<?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%">Chen, Meng</style></author><author><style face="normal" font="default" size="100%">Lopes, John M</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Multiple basic helix-loop-helix proteins regulate expression of the ENO1 gene of Saccharomyces cerevisiae.</style></title><secondary-title><style face="normal" font="default" size="100%">Eukaryot Cell</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Eukaryotic Cell</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Basic Helix-Loop-Helix Transcription Factors</style></keyword><keyword><style  face="normal" font="default" size="100%">beta-Galactosidase</style></keyword><keyword><style  face="normal" font="default" size="100%">Chromatin Immunoprecipitation</style></keyword><keyword><style  face="normal" font="default" size="100%">E-Box Elements</style></keyword><keyword><style  face="normal" font="default" size="100%">Epistasis, Genetic</style></keyword><keyword><style  face="normal" font="default" size="100%">Evolution, Molecular</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene Expression Regulation, Fungal</style></keyword><keyword><style  face="normal" font="default" size="100%">Genes, Dominant</style></keyword><keyword><style  face="normal" font="default" size="100%">Models, Biological</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutation</style></keyword><keyword><style  face="normal" font="default" size="100%">Phosphopyruvate Hydratase</style></keyword><keyword><style  face="normal" font="default" size="100%">Promoter Regions, Genetic</style></keyword><keyword><style  face="normal" font="default" size="100%">Recombinant Fusion Proteins</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></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2007 May</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">6</style></volume><pages><style face="normal" font="default" size="100%">786-96</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The basic helix-loop-helix (bHLH) eukaryotic transcription factors have the ability to form multiple dimer combinations. This property, together with limited DNA-binding specificity for the E box (CANNTG), makes them ideally suited for combinatorial control of gene expression. We tested the ability of all nine Saccharomyces cerevisiae bHLH proteins to regulate the enolase-encoding gene ENO1. ENO1 was known to be activated by the bHLH protein Sgc1p. Here we show that expression of an ENO1-lacZ reporter was also regulated by the other eight bHLH proteins, namely, Ino2p, Ino4p, Cbf1p, Rtg1p, Rtg3p, Pho4p, Hms1p, and Ygr290wp. ENO1-lacZ expression was also repressed by growth in inositol-choline-containing medium. Epistatic analysis and chromatin immunoprecipitation experiments showed that regulation by Sgc1p, Ino2p, Ino4p, and Cbf1p and repression by inositol-choline required three distal E boxes, E1, E2, and E3. The pattern of bHLH binding to the three E boxes and experiments with two dominant-negative mutant alleles of INO4 and INO2 support the model that bHLH dimer selection affects ENO1-lacZ expression. These results support the general model that bHLH proteins can coordinate different biological pathways via multiple mechanisms.</style></abstract><issue><style face="normal" font="default" size="100%">5</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/17351075?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%">Boonsombat, Ruethairat</style></author><author><style face="normal" font="default" size="100%">Yeh, Su-Ping</style></author><author><style face="normal" font="default" size="100%">Milne, Amy</style></author><author><style face="normal" font="default" size="100%">Sandler, Steven J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">A novel dnaC mutation that suppresses priB rep mutant phenotypes in Escherichia coli K-12.</style></title><secondary-title><style face="normal" font="default" size="100%">Mol Microbiol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Mol. Microbiol.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">DNA Replication</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%">Escherichia coli Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Genes, Dominant</style></keyword><keyword><style  face="normal" font="default" size="100%">Genes, Lethal</style></keyword><keyword><style  face="normal" font="default" size="100%">Genes, Recessive</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutant Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutation</style></keyword><keyword><style  face="normal" font="default" size="100%">Phenotype</style></keyword><keyword><style  face="normal" font="default" size="100%">Suppression, Genetic</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2006</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2006 May</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">60</style></volume><pages><style face="normal" font="default" size="100%">973-83</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The loading of a replisome in prokaryotic and eukaryotic cells at an origin of DNA replication and during replication restart is a highly ordered and regulated process. During replication restart in Escherichia coli, the PriA, PriB, PriC, DnaT and Rep proteins form multiple pathways that bind to repaired replication forks. These complexes are then recognized by DnaC as sites to load DnaB, the replicative helicase. Several dnaC mutations have been isolated that suppress phenotypes of some replication restart mutants. A new dnaC mutation (dnaC824) is reported here that efficiently suppresses priB rep mutant phenotypes. Furthermore, it is shown that dnaC824 will suppress phenotypes of priB priA300, rep priA300 and priB priC strains. Unlike other dnaC suppressors, it can only weakly suppress the absence of priA. Others have reported a different type of dnaC mutation, dnaC1331, is able to mimic priB mutant phenotypes. This is supported herein by showing that like dnaC1331, a priB mutation is synthetically lethal with a dam mutation and this can be rescued by a mutH mutation. Furthermore, priB dam lethality can also be suppressed by dnaC824. Like a priB mutation, a dnaC1331 mutation causes a priA2::kan-like phenotype when combined with priA300. Lastly, we show that dnaC824 is dominant to wild type and that dnaC1331 is recessive to wild type. Several models are discussed for the action of these mutant dnaC proteins in replication restart.</style></abstract><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/16677308?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%">Genetic evidence for pre-recruitment as the mechanism of transcription activation by SoxS of Escherichia coli: the dominance of DNA binding mutations of SoxS.</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%">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, Bacterial</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, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Genes, Dominant</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutation</style></keyword><keyword><style  face="normal" font="default" size="100%">Regulon</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%">2004</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2004 Nov 12</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">344</style></volume><pages><style face="normal" font="default" size="100%">1-10</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">SoxS, the direct transcriptional activator of the Escherichia coli superoxide (SoxRS) regulon, displays several unusual characteristics which suggest that it is unlikely to activate transcription by the ususal recruitment mechanism. Thus, agents that generate superoxide endogenously and thereby provoke the defense response elicit the de novo synthesis of SoxS, and with the SoxS binding site being highly degenerate, the number of SoxS binding sites per cell far exceeds the number of SoxS molecules per cell. To account for these distinctive features of the SoxRS system, we proposed &quot;pre-recruitment&quot; as the mechanism by which SoxS activates transcription of the regulon's genes. In pre-recruitment, newly synthesized SoxS molecules form binary complexes with RNA polymerase in solution. These complexes provide the information content to allow the 2500 molecules of SoxS per cell to scan the 65,000 SoxS binding sites per cell for the 200 binding sites per cell that reside within SoxS-dependent promoters. As a test of whether SoxS activates transcription by recruitment or pre-recruitment, we determined the dominance relationships of SoxS mutations conferring defective DNA binding. We found that soxS DNA binding mutations are dominant to the wild-type allele, a result consistent with the pre-recruitment hypothesis, but opposite to that expected for an activator that functions by recruitment. Moreover, whereas positive control mutations of activators functioning by recruitment are usually dominant, a soxS positive control mutation was not. Lastly, with the SoxRS system as an example, we discuss the physiological requirement for stringent regulation of transcriptional activators that function by pre-recruitment.</style></abstract><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/15504398?dopt=Abstract</style></custom1></record></records></xml>