<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Malvankar, Nikhil S</style></author><author><style face="normal" font="default" size="100%">Vargas, Madeline</style></author><author><style face="normal" font="default" size="100%">Nevin, Kelly</style></author><author><style face="normal" font="default" size="100%">Tremblay, Pier-Luc</style></author><author><style face="normal" font="default" size="100%">Evans-Lutterodt, Kenneth</style></author><author><style face="normal" font="default" size="100%">Nykypanchuk, Dmytro</style></author><author><style face="normal" font="default" size="100%">Martz, Eric</style></author><author><style face="normal" font="default" size="100%">Tuominen, Mark T</style></author><author><style face="normal" font="default" size="100%">Lovley, Derek R</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Structural basis for metallic-like conductivity in microbial nanowires.</style></title><secondary-title><style face="normal" font="default" size="100%">mBio</style></secondary-title><alt-title><style face="normal" font="default" size="100%">mBio</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Amino Acids, Aromatic</style></keyword><keyword><style  face="normal" font="default" size="100%">Chemical Phenomena</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrophysiological Phenomena</style></keyword><keyword><style  face="normal" font="default" size="100%">Fimbriae, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Geobacter</style></keyword><keyword><style  face="normal" font="default" size="100%">Hydrogen-Ion Concentration</style></keyword><keyword><style  face="normal" font="default" size="100%">Models, Molecular</style></keyword><keyword><style  face="normal" font="default" size="100%">Nanowires</style></keyword><keyword><style  face="normal" font="default" size="100%">X-Ray Diffraction</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2015</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2015 Mar 03</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">6</style></volume><pages><style face="normal" font="default" size="100%">e00084</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;&lt;b&gt;UNLABELLED: &lt;/b&gt;Direct measurement of multiple physical properties of Geobacter sulfurreducens pili have demonstrated that they possess metallic-like conductivity, but several studies have suggested that metallic-like conductivity is unlikely based on the structures of the G. sulfurreducens pilus predicted from homology models. In order to further evaluate this discrepancy, pili were examined with synchrotron X-ray microdiffraction and rocking-curve X-ray diffraction. Both techniques revealed a periodic 3.2-Å spacing in conductive, wild-type G. sulfurreducens pili that was missing in the nonconductive pili of strain Aro5, which lack key aromatic acids required for conductivity. The intensity of the 3.2-Å peak increased 100-fold when the pH was shifted from 10.5 to 2, corresponding with a previously reported 100-fold increase in pilus conductivity with this pH change. These results suggest a clear structure-function correlation for metallic-like conductivity that can be attributed to overlapping π-orbitals of aromatic amino acids. A homology model of the G. sulfurreducens pilus was constructed with a Pseudomonas aeruginosa pilus model as a template as an alternative to previous models, which were based on a Neisseria gonorrhoeae pilus structure. This alternative model predicted that aromatic amino acids in G. sulfurreducens pili are packed within 3 to 4 Å, consistent with the experimental results. Thus, the predictions of homology modeling are highly sensitive to assumptions inherent in the model construction. The experimental results reported here further support the concept that the pili of G. sulfurreducens represent a novel class of electronically functional proteins in which aromatic amino acids promote long-distance electron transport.&lt;/p&gt;&lt;p&gt;&lt;b&gt;IMPORTANCE: &lt;/b&gt;The mechanism for long-range electron transport along the conductive pili of Geobacter sulfurreducens is of interest because these &quot;microbial nanowires&quot; are important in biogeochemical cycling as well as applications in bioenergy and bioelectronics. Although proteins are typically insulators, G. sulfurreducens pilus proteins possess metallic-like conductivity. The studies reported here provide important structural insights into the mechanism of the metallic-like conductivity of G. sulfurreducens pili. This information is expected to be useful in the design of novel bioelectronic materials.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue><custom1><style face="normal" font="default" size="100%">https://www.ncbi.nlm.nih.gov/pubmed/25736881?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Park, Kwang-Hyun</style></author><author><style face="normal" font="default" size="100%">Jung, Jong-Hyun</style></author><author><style face="normal" font="default" size="100%">Park, Sung-Goo</style></author><author><style face="normal" font="default" size="100%">Lee, Myeong-Eun</style></author><author><style face="normal" font="default" size="100%">Holden, James F</style></author><author><style face="normal" font="default" size="100%">Park, Cheon-Seok</style></author><author><style face="normal" font="default" size="100%">Woo, Eui-Jeon</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Structural features underlying the selective cleavage of a novel exo-type maltose-forming amylase from Pyrococcus sp. ST04.</style></title><secondary-title><style face="normal" font="default" size="100%">Acta Crystallogr D Biol Crystallogr</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Acta Crystallogr. D Biol. Crystallogr.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Amylases</style></keyword><keyword><style  face="normal" font="default" size="100%">Catalytic Domain</style></keyword><keyword><style  face="normal" font="default" size="100%">Maltose</style></keyword><keyword><style  face="normal" font="default" size="100%">Models, Molecular</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutagenesis, Site-Directed</style></keyword><keyword><style  face="normal" font="default" size="100%">Protein Conformation</style></keyword><keyword><style  face="normal" font="default" size="100%">Proteolysis</style></keyword><keyword><style  face="normal" font="default" size="100%">Pyrococcus</style></keyword><keyword><style  face="normal" font="default" size="100%">Substrate Specificity</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2014</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2014 Jun</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">70</style></volume><pages><style face="normal" font="default" size="100%">1659-68</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;A novel maltose-forming &amp;alpha;-amylase (PSMA) was recently found in the hyperthermophilic archaeon Pyrococcus sp. ST04. This enzyme shows &amp;lt;13% amino-acid sequence identity to other known &amp;alpha;-amylases and displays a unique enzymatic property in that it hydrolyzes both &amp;alpha;-1,4-glucosidic and &amp;alpha;-1,6-glucosidic linkages of substrates, recognizing only maltose units, in an exo-type manner. Here, the crystal structure of PSMA at a resolution of 1.8 &amp;Aring; is reported, showing a tight ring-shaped tetramer with monomers composed of two domains: an N-domain (amino acids 1-341) with a typical GH57 family (&amp;beta;/&amp;alpha;)7-barrel fold and a C-domain (amino acids 342-597) composed of &amp;alpha;-helical bundles. A small closed cavity observed in proximity to the catalytic residues Glu153 and Asp253 at the domain interface has the appropriate volume and geometry to bind a maltose unit, accounting for the selective exo-type maltose hydrolysis of the enzyme. A narrow gate at the putative subsite +1 formed by residue Phe218 and Phe452 is essential for specific cleavage of glucosidic bonds. The closed cavity at the active site is connected to a short substrate-binding channel that extends to the central hole of the tetramer, exhibiting a geometry that is significantly different from classical maltogenic amylases or &amp;beta;-amylases. The structural features of this novel exo-type maltose-forming &amp;alpha;-amylase provide a molecular basis for its unique enzymatic characteristics and for its potential use in industrial applications and protein engineering.&lt;/p&gt;
</style></abstract><issue><style face="normal" font="default" size="100%">Pt 6</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Prilusky, Jaime</style></author><author><style face="normal" font="default" size="100%">Hodis, Eran</style></author><author><style face="normal" font="default" size="100%">Canner, David</style></author><author><style face="normal" font="default" size="100%">Decatur, Wayne A</style></author><author><style face="normal" font="default" size="100%">Oberholser, Karl</style></author><author><style face="normal" font="default" size="100%">Martz, Eric</style></author><author><style face="normal" font="default" size="100%">Berchanski, Alexander</style></author><author><style face="normal" font="default" size="100%">Harel, Michal</style></author><author><style face="normal" font="default" size="100%">Sussman, Joel L</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Proteopedia: a status report on the collaborative, 3D web-encyclopedia of proteins and other biomolecules.</style></title><secondary-title><style face="normal" font="default" size="100%">J Struct Biol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">J. Struct. Biol.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Encyclopedias as Topic</style></keyword><keyword><style  face="normal" font="default" size="100%">Information Dissemination</style></keyword><keyword><style  face="normal" font="default" size="100%">Information Management</style></keyword><keyword><style  face="normal" font="default" size="100%">Information Services</style></keyword><keyword><style  face="normal" font="default" size="100%">Models, Molecular</style></keyword><keyword><style  face="normal" font="default" size="100%">Molecular Biology</style></keyword><keyword><style  face="normal" font="default" size="100%">Online Systems</style></keyword><keyword><style  face="normal" font="default" size="100%">Protein Conformation</style></keyword><keyword><style  face="normal" font="default" size="100%">Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">User-Computer Interface</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2011 Aug</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">175</style></volume><pages><style face="normal" font="default" size="100%">244-52</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Proteopedia is a collaborative, 3D web-encyclopedia of protein, nucleic acid and other biomolecule structures. Created as a means for communicating biomolecule structures to a diverse scientific audience, Proteopedia (http://www.proteopedia.org) presents structural annotation in an intuitive, interactive format and allows members of the scientific community to easily contribute their own annotations. Here, we provide a status report on Proteopedia by describing advances in the web resource since its inception three and a half years ago, focusing on features of potential direct use to the scientific community. We discuss its progress as a collaborative 3D-encyclopedia of structures as well as its use as a complement to scientific publications and PowerPoint presentations. We also describe Proteopedia's use for 3D visualization in structure-related pedagogy.</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/21536137?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Martz, Eric</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Proteopedia.Org: a scientific &quot;Wiki&quot; bridging the rift between 3D structure and function of biomacromolecules.</style></title><secondary-title><style face="normal" font="default" size="100%">Biopolymers</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Biopolymers</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Computational Biology</style></keyword><keyword><style  face="normal" font="default" size="100%">Imaging, Three-Dimensional</style></keyword><keyword><style  face="normal" font="default" size="100%">Internet</style></keyword><keyword><style  face="normal" font="default" size="100%">Models, Molecular</style></keyword><keyword><style  face="normal" font="default" size="100%">Protein Structure, Quaternary</style></keyword><keyword><style  face="normal" font="default" size="100%">Protein Structure, Tertiary</style></keyword><keyword><style  face="normal" font="default" size="100%">Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Structure-Activity Relationship</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2009</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">92</style></volume><pages><style face="normal" font="default" size="100%">76-7</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><issue><style face="normal" font="default" size="100%">1</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/19117028?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Hodis, Eran</style></author><author><style face="normal" font="default" size="100%">Prilusky, Jaime</style></author><author><style face="normal" font="default" size="100%">Martz, Eric</style></author><author><style face="normal" font="default" size="100%">Silman, Israel</style></author><author><style face="normal" font="default" size="100%">Moult, John</style></author><author><style face="normal" font="default" size="100%">Sussman, Joel L</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Proteopedia - a scientific 'wiki' bridging the rift between three-dimensional structure and function of biomacromolecules.</style></title><secondary-title><style face="normal" font="default" size="100%">Genome Biol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Genome Biol.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Databases, Protein</style></keyword><keyword><style  face="normal" font="default" size="100%">Internet</style></keyword><keyword><style  face="normal" font="default" size="100%">Models, Molecular</style></keyword><keyword><style  face="normal" font="default" size="100%">Protein Conformation</style></keyword><keyword><style  face="normal" font="default" size="100%">Protein Structure, Tertiary</style></keyword><keyword><style  face="normal" font="default" size="100%">Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Software</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2008</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">9</style></volume><pages><style face="normal" font="default" size="100%">R121</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Many scientists lack the background to fully utilize the wealth of solved three-dimensional biomacromolecule structures. Thus, a resource is needed to present structure/function information in a user-friendly manner to a broad scientific audience. Proteopedia http://www.proteopedia.org is an interactive, wiki web-resource whose pages have embedded three-dimensional structures surrounded by descriptive text containing hyperlinks that change the appearance (view, representations, colors, labels) of the adjacent three-dimensional structure to reflect the concept explained in the text.</style></abstract><issue><style face="normal" font="default" size="100%">8</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/18673581?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Stern, Adi</style></author><author><style face="normal" font="default" size="100%">Doron-Faigenboim, Adi</style></author><author><style face="normal" font="default" size="100%">Erez, Elana</style></author><author><style face="normal" font="default" size="100%">Martz, Eric</style></author><author><style face="normal" font="default" size="100%">Bacharach, Eran</style></author><author><style face="normal" font="default" size="100%">Pupko, Tal</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Selecton 2007: advanced models for detecting positive and purifying selection using a Bayesian inference approach.</style></title><secondary-title><style face="normal" font="default" size="100%">Nucleic Acids Res</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Nucleic Acids Res.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Algorithms</style></keyword><keyword><style  face="normal" font="default" size="100%">Amino Acid Sequence</style></keyword><keyword><style  face="normal" font="default" size="100%">Amino Acid Substitution</style></keyword><keyword><style  face="normal" font="default" size="100%">Amino Acids</style></keyword><keyword><style  face="normal" font="default" size="100%">Animals</style></keyword><keyword><style  face="normal" font="default" size="100%">Bayes Theorem</style></keyword><keyword><style  face="normal" font="default" size="100%">Computational Biology</style></keyword><keyword><style  face="normal" font="default" size="100%">Computer Simulation</style></keyword><keyword><style  face="normal" font="default" size="100%">Humans</style></keyword><keyword><style  face="normal" font="default" size="100%">Internet</style></keyword><keyword><style  face="normal" font="default" size="100%">Models, Molecular</style></keyword><keyword><style  face="normal" font="default" size="100%">Molecular Sequence Data</style></keyword><keyword><style  face="normal" font="default" size="100%">Phylogeny</style></keyword><keyword><style  face="normal" font="default" size="100%">Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Sequence Analysis, Protein</style></keyword><keyword><style  face="normal" font="default" size="100%">Software</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2007 Jul</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">35</style></volume><pages><style face="normal" font="default" size="100%">W506-11</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Biologically significant sites in a protein may be identified by contrasting the rates of synonymous (K(s)) and non-synonymous (K(a)) substitutions. This enables the inference of site-specific positive Darwinian selection and purifying selection. We present here Selecton version 2.2 (http://selecton.bioinfo.tau.ac.il), a web server which automatically calculates the ratio between K(a) and K(s) (omega) at each site of the protein. This ratio is graphically displayed on each site using a color-coding scheme, indicating either positive selection, purifying selection or lack of selection. Selecton implements an assembly of different evolutionary models, which allow for statistical testing of the hypothesis that a protein has undergone positive selection. Specifically, the recently developed mechanistic-empirical model is introduced, which takes into account the physicochemical properties of amino acids. Advanced options were introduced to allow maximal fine tuning of the server to the user's specific needs, including calculation of statistical support of the omega values, an advanced graphic display of the protein's 3-dimensional structure, use of different genetic codes and inputting of a pre-built phylogenetic tree. Selecton version 2.2 is an effective, user-friendly and freely available web server which implements up-to-date methods for computing site-specific selection forces, and the visualization of these forces on the protein's sequence and structure.</style></abstract><issue><style face="normal" font="default" size="100%">Web Server issue</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/17586822?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Landau, Meytal</style></author><author><style face="normal" font="default" size="100%">Mayrose, Itay</style></author><author><style face="normal" font="default" size="100%">Rosenberg, Yossi</style></author><author><style face="normal" font="default" size="100%">Glaser, Fabian</style></author><author><style face="normal" font="default" size="100%">Martz, Eric</style></author><author><style face="normal" font="default" size="100%">Pupko, Tal</style></author><author><style face="normal" font="default" size="100%">Ben-Tal, Nir</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">ConSurf 2005: the projection of evolutionary conservation scores of residues on protein structures.</style></title><secondary-title><style face="normal" font="default" size="100%">Nucleic Acids Res</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Nucleic Acids Res.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Amino Acid Substitution</style></keyword><keyword><style  face="normal" font="default" size="100%">Amino Acids</style></keyword><keyword><style  face="normal" font="default" size="100%">Bacterial Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Bayes Theorem</style></keyword><keyword><style  face="normal" font="default" size="100%">Evolution, Molecular</style></keyword><keyword><style  face="normal" font="default" size="100%">Internet</style></keyword><keyword><style  face="normal" font="default" size="100%">Models, Molecular</style></keyword><keyword><style  face="normal" font="default" size="100%">Potassium Channels</style></keyword><keyword><style  face="normal" font="default" size="100%">Protein Conformation</style></keyword><keyword><style  face="normal" font="default" size="100%">Software</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2005</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2005 Jul 1</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">33</style></volume><pages><style face="normal" font="default" size="100%">W299-302</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Key amino acid positions that are important for maintaining the 3D structure of a protein and/or its function(s), e.g. catalytic activity, binding to ligand, DNA or other proteins, are often under strong evolutionary constraints. Thus, the biological importance of a residue often correlates with its level of evolutionary conservation within the protein family. ConSurf (http://consurf.tau.ac.il/) is a web-based tool that automatically calculates evolutionary conservation scores and maps them on protein structures via a user-friendly interface. Structurally and functionally important regions in the protein typically appear as patches of evolutionarily conserved residues that are spatially close to each other. We present here version 3.0 of ConSurf. This new version includes an empirical Bayesian method for scoring conservation, which is more accurate than the maximum-likelihood method that was used in the earlier release. Various additional steps in the calculation can now be controlled by a number of advanced options, thus further improving the accuracy of the calculation. Moreover, ConSurf version 3.0 also includes a measure of confidence for the inferred amino acid conservation scores.</style></abstract><issue><style face="normal" font="default" size="100%">Web Server issue</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/15980475?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Griffith, Kevin L</style></author><author><style face="normal" font="default" size="100%">Wolf, Richard E</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">A comprehensive alanine scanning mutagenesis of the Escherichia coli transcriptional activator SoxS: identifying amino acids important for DNA binding and transcription activation.</style></title><secondary-title><style face="normal" font="default" size="100%">J Mol Biol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">J. Mol. Biol.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Alanine</style></keyword><keyword><style  face="normal" font="default" size="100%">Amino Acid Substitution</style></keyword><keyword><style  face="normal" font="default" size="100%">Base Sequence</style></keyword><keyword><style  face="normal" font="default" size="100%">Binding Sites</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA-Binding Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrophoretic Mobility Shift Assay</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene Expression Regulation, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Genes, Lethal</style></keyword><keyword><style  face="normal" font="default" size="100%">Hydrophobic and Hydrophilic Interactions</style></keyword><keyword><style  face="normal" font="default" size="100%">Lac Operon</style></keyword><keyword><style  face="normal" font="default" size="100%">Models, Molecular</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutagenesis</style></keyword><keyword><style  face="normal" font="default" size="100%">Nucleic Acid Conformation</style></keyword><keyword><style  face="normal" font="default" size="100%">Phenotype</style></keyword><keyword><style  face="normal" font="default" size="100%">Phosphates</style></keyword><keyword><style  face="normal" font="default" size="100%">Promoter Regions, Genetic</style></keyword><keyword><style  face="normal" font="default" size="100%">Protein Binding</style></keyword><keyword><style  face="normal" font="default" size="100%">Protein Structure, Tertiary</style></keyword><keyword><style  face="normal" font="default" size="100%">Structure-Activity Relationship</style></keyword><keyword><style  face="normal" font="default" size="100%">Trans-Activators</style></keyword><keyword><style  face="normal" font="default" size="100%">Transcriptional Activation</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2002</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2002 Sep 13</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">322</style></volume><pages><style face="normal" font="default" size="100%">237-57</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">SoxS is the direct transcriptional activator of the superoxide regulon. SoxS recognizes a highly degenerate &quot;soxbox&quot; DNA sequence, and activates transcription from class I and class II promoters. SoxS is the smallest member of the AraC/XylS family of transcription regulators whose hallmark is dual helix-turn-helix (HTH) DNA-binding motifs. Evidence suggests that the N-terminal HTH motif of SoxS interacts with a highly conserved region of the soxbox termed recognition element 1 (RE1), while the C-terminal HTH motif interacts with the less conserved recognition element 2 (RE2). In the work described here, we prepared a complete library of 101 SoxS mutants containing single alanine substitutions of SoxS, and we characterized the mutant proteins in vivo and in vitro. With SoxS being closely related to MarA, we analyzed the effects of the SoxS mutations in the context of the MarA-mar crystal structure and with respect to the NMR study of MarA-DNA complexes in solution. From the properties of the alanine substitutions, we conclude the following. (1) Surface-exposed residues of helix 3 and helix 6, the recognition helices of the dual HTH motifs, are important to DNA binding and transcription activation; however, substitutions of residues predicted from the MarA-mar crystal structure to make contact with the sugar-phosphate backbone are more detrimental to DNA binding than mutations predicted to make base-specific contacts. (2) Substitution of several residues within the recognition helix predicted to make base-specific contacts with RE2 have relatively little effect on DNA-binding, suggesting the possibility of alternative protein-DNA interactions than those inferred from the MarA-mar crystal structure. (3) DNA binding and transcription activation were reduced by substitution of conserved amino acid residues comprising the hydrophobic core, presumably because they disrupt the structural integrity of SoxS. (4) Mutant K30A appears to be a positive control mutant defective in a protein-protein interaction with RNA polymerase that is required for transcription activation at all SoxS-dependent promoters because it binds and bends DNA normally but fails to activate transcription from both classes of promoters. Alanine substitutions of surface-exposed residues H3, K5, D9, S31, and V45 confer a similar phenotype. Since these residues are near K30 on the surface of the protein, the surface formed by the six residues may be used to make protein-protein interactions with RNA polymerase that are required for transcription activation at both class I and class II SoxS-dependent promoters. (5) Mutants F74A, D75A, M78A, D79A and Q85A appear to define a surface required for protein-protein interaction with RNA polymerase specifically at class II promoters because these positive control mutants bind and bend DNA normally but are defective in activation of class II promoters but not class I promoters. These SoxS mutants that bind and bend DNA normally but are defective in transcription activation represent the first positive control mutants with putative defects in protein-protein interactions with RNA polymerase among the SoxS/MarA/Rob subset of the AraC/XylS family of transcription regulators.</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/12217688?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Sandler, S J</style></author><author><style face="normal" font="default" size="100%">Satin, L H</style></author><author><style face="normal" font="default" size="100%">Samra, H S</style></author><author><style face="normal" font="default" size="100%">Clark, A J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">recA-like genes from three archaean species with putative protein products similar to Rad51 and Dmc1 proteins of the yeast Saccharomyces cerevisiae.</style></title><secondary-title><style face="normal" font="default" size="100%">Nucleic Acids Res</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Nucleic Acids Res.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Amino Acid Sequence</style></keyword><keyword><style  face="normal" font="default" size="100%">Archaea</style></keyword><keyword><style  face="normal" font="default" size="100%">Base Sequence</style></keyword><keyword><style  face="normal" font="default" size="100%">Cell Cycle Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA-Binding Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli</style></keyword><keyword><style  face="normal" font="default" size="100%">Halobacteriaceae</style></keyword><keyword><style  face="normal" font="default" size="100%">Methanococcus</style></keyword><keyword><style  face="normal" font="default" size="100%">Models, Molecular</style></keyword><keyword><style  face="normal" font="default" size="100%">Molecular Sequence Data</style></keyword><keyword><style  face="normal" font="default" size="100%">Phylogeny</style></keyword><keyword><style  face="normal" font="default" size="100%">Rad51 Recombinase</style></keyword><keyword><style  face="normal" font="default" size="100%">Rec A Recombinases</style></keyword><keyword><style  face="normal" font="default" size="100%">Saccharomyces cerevisiae</style></keyword><keyword><style  face="normal" font="default" size="100%">Saccharomyces cerevisiae Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Sequence Alignment</style></keyword><keyword><style  face="normal" font="default" size="100%">Sulfolobus</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1996</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1996 Jun 1</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">24</style></volume><pages><style face="normal" font="default" size="100%">2125-32</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The process of homologous recombination has been documented in bacterial and eucaryotic organisms. The Escherichia coli RecA and Saccharomyces cerevisiae Rad51 proteins are the archetypal members of two related families of proteins that play a central role in this process. Using the PCR process primed by degenerate oligonucleotides designed to encode regions of the proteins showing the greatest degree of identity, we examined DNA from three organisms of a third phylogenetically divergent group, Archaea, for sequences encoding proteins similar to RecA and Rad51. The archaeans examined were a hyperthermophilic acidophile, Sulfolobus sofataricus (Sso); a halophile, Haloferax volcanii (Hvo); and a hyperthermophilic piezophilic methanogen, Methanococcus jannaschii (Mja). The PCR generated DNA was used to clone a larger genomic DNA fragment containing an open reading frame (orf), that we refer to as the radA gene, for each of the three archaeans. As shown by amino acid sequence alignments, percent amino acid identities and phylogenetic analysis, the putative proteins encoded by all three are related to each other and to both the RecA and Rad51 families of proteins. The putative RadA proteins are more similar to the Rad51 family (approximately 40% identity at the amino acid level) than to the RecA family (approximately 20%). Conserved sequence motifs, putative tertiary structures and phylogenetic analysis implied by the alignment are discussed. The 5' ends of mRNA transcripts to the Sso radA were mapped. The levels of radA mRNA do not increase after treatment with UV irradiation as do recA and RAD51 transcripts in E.coli and S.cerevisiae. Hence it is likely that radA in this organism is a constitutively expressed gene and we discuss possible implications of the lack of UV-inducibility.</style></abstract><issue><style face="normal" font="default" size="100%">11</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/8668545?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Norkin, L C</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Virus receptors: implications for pathogenesis and the design of antiviral agents.</style></title><secondary-title><style face="normal" font="default" size="100%">Clin Microbiol Rev</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Clin. Microbiol. Rev.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Antigens, CD4</style></keyword><keyword><style  face="normal" font="default" size="100%">Antiviral Agents</style></keyword><keyword><style  face="normal" font="default" size="100%">Coronavirus</style></keyword><keyword><style  face="normal" font="default" size="100%">Drug Design</style></keyword><keyword><style  face="normal" font="default" size="100%">Herpesviridae</style></keyword><keyword><style  face="normal" font="default" size="100%">HIV</style></keyword><keyword><style  face="normal" font="default" size="100%">Humans</style></keyword><keyword><style  face="normal" font="default" size="100%">Intercellular Adhesion Molecule-1</style></keyword><keyword><style  face="normal" font="default" size="100%">Models, Molecular</style></keyword><keyword><style  face="normal" font="default" size="100%">Picornaviridae</style></keyword><keyword><style  face="normal" font="default" size="100%">Receptors, Virus</style></keyword><keyword><style  face="normal" font="default" size="100%">Retroviridae</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1995</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1995 Apr</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">8</style></volume><pages><style face="normal" font="default" size="100%">293-315</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">A virus initiates infection by attaching to its specific receptor on the surface of a susceptible host cell. This prepares the way for the virus to enter the cell. Consequently, the expression of the receptor on specific cells and tissues of the host is a major determinant of the route of entry of the virus into the host and of the patterns of virus spread and pathogenesis in the host. This review emphasizes the virus-receptor interactions of human immunodeficiency virus, the rhinoviruses, the herpesviruses, and the coronaviruses. These interactions are often found to be complex and dynamic, involving multiple sites or factors on both the virus and the host cell. Also, the receptor may play an important role in virus entry per se in addition to its role in virus binding. In the cases of human immunodeficiency virus and the rhinoviruses, ingenious approaches to therapeutic strategies based on inhibiting virus attachment and entry are under development and in clinical trials.</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/7621403?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Hendrickson, W A</style></author><author><style face="normal" font="default" size="100%">Ward, K B</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Atomic models for the polypeptide backbones of myohemerythrin and hemerythrin.</style></title><secondary-title><style face="normal" font="default" size="100%">Biochem Biophys Res Commun</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Biochem. Biophys. Res. Commun.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Animals</style></keyword><keyword><style  face="normal" font="default" size="100%">Cnidaria</style></keyword><keyword><style  face="normal" font="default" size="100%">Computers</style></keyword><keyword><style  face="normal" font="default" size="100%">Hemerythrin</style></keyword><keyword><style  face="normal" font="default" size="100%">Metalloproteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Models, Molecular</style></keyword><keyword><style  face="normal" font="default" size="100%">Muscle Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Protein Conformation</style></keyword><keyword><style  face="normal" font="default" size="100%">Species Specificity</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1975</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1975 Oct 27</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">66</style></volume><pages><style face="normal" font="default" size="100%">1349-56</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><issue><style face="normal" font="default" size="100%">4</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/5?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Bose, K S</style></author><author><style face="normal" font="default" size="100%">Sarma, R H</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Delineation of the intimate details of the backbone conformation of pyridine nucleotide coenzymes in aqueous solution.</style></title><secondary-title><style face="normal" font="default" size="100%">Biochem Biophys Res Commun</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Biochem. Biophys. Res. Commun.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Fourier Analysis</style></keyword><keyword><style  face="normal" font="default" size="100%">Magnetic Resonance Spectroscopy</style></keyword><keyword><style  face="normal" font="default" size="100%">Models, Molecular</style></keyword><keyword><style  face="normal" font="default" size="100%">Molecular Conformation</style></keyword><keyword><style  face="normal" font="default" size="100%">NAD</style></keyword><keyword><style  face="normal" font="default" size="100%">NADP</style></keyword><keyword><style  face="normal" font="default" size="100%">Structure-Activity Relationship</style></keyword><keyword><style  face="normal" font="default" size="100%">Temperature</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1975</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1975 Oct 27</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">66</style></volume><pages><style face="normal" font="default" size="100%">1173-9</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><issue><style face="normal" font="default" size="100%">4</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/2?dopt=Abstract</style></custom1></record></records></xml>