@article {515,
	title = {c-Type cytochromes in Pelobacter carbinolicus.},
	journal = {Appl Environ Microbiol},
	volume = {72},
	year = {2006},
	month = {2006 Nov},
	pages = {6980-5},
	abstract = {Previous studies failed to detect c-type cytochromes in Pelobacter species despite the fact that other close relatives in the Geobacteraceae, such as Geobacter and Desulfuromonas species, have abundant c-type cytochromes. Analysis of the recently completed genome sequence of Pelobacter carbinolicus revealed 14 open reading frames that could encode c-type cytochromes. Transcripts for all but one of these open reading frames were detected in acetoin-fermenting and/or Fe(III)-reducing cells. Three putative c-type cytochrome genes were expressed specifically during Fe(III) reduction, suggesting that the encoded proteins may participate in electron transfer to Fe(III). One of these proteins was a periplasmic triheme cytochrome with a high level of similarity to PpcA, which has a role in Fe(III) reduction in Geobacter sulfurreducens. Genes for heme biosynthesis and system II cytochrome c biogenesis were identified in the genome and shown to be expressed. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels of protein extracted from acetoin-fermenting P. carbinolicus cells contained three heme-staining bands which were confirmed by mass spectrometry to be among the 14 predicted c-type cytochromes. The number of cytochrome genes, the predicted amount of heme c per protein, and the ratio of heme-stained protein to total protein were much smaller in P. carbinolicus than in G. sulfurreducens. Furthermore, many of the c-type cytochromes that genetic studies have indicated are required for optimal Fe(III) reduction in G. sulfurreducens were not present in the P. carbinolicus genome. These results suggest that further evaluation of the functions of c-type cytochromes in the Geobacteraceae is warranted.},
	keywords = {Bacterial Proteins, Cytochromes c, Deltaproteobacteria, Heme, Polymerase Chain Reaction, Proteomics, Reverse Transcriptase Polymerase Chain Reaction, RNA, Messenger},
	issn = {0099-2240},
	doi = {10.1128/AEM.01128-06},
	author = {Haveman, Shelley A and Holmes, Dawn E and Ding, Yan-Huai R and Ward, Joy E and Didonato, Raymond J and Lovley, Derek R}
}
@article {536,
	title = {OmcF, a putative c-Type monoheme outer membrane cytochrome required for the expression of other outer membrane cytochromes in Geobacter sulfurreducens.},
	journal = {J Bacteriol},
	volume = {187},
	year = {2005},
	month = {2005 Jul},
	pages = {4505-13},
	abstract = {Outer membrane cytochromes are often proposed as likely agents for electron transfer to extracellular electron acceptors, such as Fe(III). The omcF gene in the dissimilatory Fe(III)-reducing microorganism Geobacter sulfurreducens is predicted to code for a small outer membrane monoheme c-type cytochrome. An OmcF-deficient strain was constructed, and its ability to reduce and grow on Fe(III) citrate was found to be impaired. Following a prolonged lag phase (150 h), the OmcF-deficient strain developed the ability to grow in Fe(III) citrate medium with doubling times and yields that were ca. 145\% and 70\% of those of the wild type, respectively. Comparison of the c-type cytochrome contents of outer membrane-enriched fractions prepared from wild-type and OmcF-deficient cultures confirmed the outer membrane association of OmcF and revealed multiple changes in the cytochrome content of the OmcF-deficient strain. These changes included loss of expression of two previously characterized outer membrane cytochromes, OmcB and OmcC, and overexpression of a third previously characterized outer membrane cytochrome, OmcS, during growth on Fe(III) citrate. The omcB and omcC transcripts could not be detected in the OmcF-deficient mutant by either reverse transcriptase PCR or Northern blot analyses. Expression of the omcF gene in trans restored both the capacity of the OmcF-deficient mutant to reduce Fe(III) and wild-type levels of omcB and omcC mRNA and protein. Thus, elimination of OmcF may impair Fe(III) reduction by influencing expression of OmcB, which has previously been demonstrated to play a critical role in Fe(III) reduction.},
	keywords = {Amino Acid Sequence, Bacterial Outer Membrane Proteins, Cytochromes c, Ferric Compounds, Gene Deletion, Gene Expression Regulation, Bacterial, Geobacter, Molecular Sequence Data, Oxidation-Reduction, Sequence Alignment},
	issn = {0021-9193},
	doi = {10.1128/JB.187.13.4505-4513.2005},
	author = {Kim, Byoung-Chan and Leang, Ching and Ding, Yan-Huai R and Glaven, Richard H and Coppi, Maddalena V and Lovley, Derek R}
}
