@article {3131,
	title = {A Geobacter sulfurreducens strain expressing pseudomonas aeruginosa type IV pili localizes OmcS on pili but is deficient in Fe(III) oxide reduction and current production.},
	journal = {Appl Environ Microbiol},
	volume = {80},
	year = {2014},
	month = {2014 Feb},
	pages = {1219-24},
	abstract = {<p>The conductive pili of Geobacter species play an important role in electron transfer to Fe(III) oxides, in long-range electron transport through current-producing biofilms, and in direct interspecies electron transfer. Although multiple lines of evidence have indicated that the pili of Geobacter sulfurreducens have a metal-like conductivity, independent of the presence of c-type cytochromes, this claim is still controversial. In order to further investigate this phenomenon, a strain of G. sulfurreducens, designated strain PA, was constructed in which the gene for the native PilA, the structural pilin protein, was replaced with the PilA gene of Pseudomonas aeruginosa PAO1. Strain PA expressed and properly assembled P. aeruginosa PilA subunits into pili and exhibited a profile of outer surface c-type cytochromes similar to that of a control strain expressing the G. sulfurreducens PilA. Surprisingly, the strain PA pili were decorated with the c-type cytochrome OmcS in a manner similar to the control strain. However, the strain PA pili were 14-fold less conductive than the pili of the control strain, and strain PA was severely impaired in Fe(III) oxide reduction and current production. These results demonstrate that the presence of OmcS on pili is not sufficient to confer conductivity to pili and suggest that there are unique structural features of the G. sulfurreducens PilA that are necessary for conductivity.</p>},
	keywords = {Amino Acid Sequence, Cytochromes c, Electricity, Ferric Compounds, Fimbriae Proteins, Fimbriae, Bacterial, Geobacter, Methanosarcinaceae, Molecular Sequence Data, Oxidation-Reduction, Pseudomonas aeruginosa, Sequence Alignment},
	issn = {1098-5336},
	doi = {10.1128/AEM.02938-13},
	author = {Liu, Xing and Tremblay, Pier-Luc and Malvankar, Nikhil S and Nevin, Kelly P and Lovley, Derek R and Vargas, Madeline}
}
@article {3151,
	title = {Outer cell surface components essential for Fe(III) oxide reduction by Geobacter metallireducens.},
	journal = {Appl Environ Microbiol},
	volume = {79},
	year = {2013},
	month = {2013 Feb},
	pages = {901-7},
	abstract = {<p>Geobacter species are important Fe(III) reducers in a diversity of soils and sediments. Mechanisms for Fe(III) oxide reduction have been studied in detail in Geobacter sulfurreducens, but a number of the most thoroughly studied outer surface components of G. sulfurreducens, particularly c-type cytochromes, are not well conserved among Geobacter species. In order to identify cellular components potentially important for Fe(III) oxide reduction in Geobacter metallireducens, gene transcript abundance was compared in cells grown on Fe(III) oxide or soluble Fe(III) citrate with whole-genome microarrays. Outer-surface cytochromes were also identified. Deletion of genes for c-type cytochromes that had higher transcript abundance during growth on Fe(III) oxides and/or were detected in the outer-surface protein fraction identified six c-type cytochrome genes, that when deleted removed the capacity for Fe(III) oxide reduction. Several of the c-type cytochromes which were essential for Fe(III) oxide reduction in G. metallireducens have homologs in G. sulfurreducens that are not important for Fe(III) oxide reduction. Other genes essential for Fe(III) oxide reduction included a gene predicted to encode an NHL (Ncl-1-HT2A-Lin-41) repeat-containing protein and a gene potentially involved in pili glycosylation. Genes associated with flagellum-based motility, chemotaxis, and pili had higher transcript abundance during growth on Fe(III) oxide, consistent with the previously proposed importance of these components in Fe(III) oxide reduction. These results demonstrate that there are similarities in extracellular electron transfer between G. metallireducens and G. sulfurreducens but the outer-surface c-type cytochromes involved in Fe(III) oxide reduction are different.</p>},
	keywords = {Bacterial Proteins, Culture Media, Cytochromes c, Electron Transport, Ferric Compounds, Gene Deletion, Gene Expression Profiling, Geobacter, Microarray Analysis, Oxidation-Reduction},
	issn = {1098-5336},
	doi = {10.1128/AEM.02954-12},
	author = {Smith, Jessica A and Lovley, Derek R and Tremblay, Pier-Luc}
}
