@article {422,
	title = {Genome diversity of the TetR family of transcriptional regulators in a metal-reducing bacterial family Geobacteraceae and other microbial species.},
	journal = {OMICS},
	volume = {15},
	year = {2011},
	month = {2011 Jul-Aug},
	pages = {495-506},
	abstract = {Members of the TetR family of bacterial transcriptional regulators affect expression of genes whose products are involved in a variety of important functions, including osmotic stress, catabolic pathways, homeostasis, biosynthesis of antibiotics, expression of efflux pumps, multidrug resistance, and virulence of pathogenic bacteria. We used genome sequence information to carry out phylogenetic classification of 864 TetR family members with a special focus on TetR regulators in Geobacteraceae, an environmentally important family of delta-Proteobacteria. The genome of Geobacter sulfurreducens, a model representative of Geobacteraceae, contains nine genes from the tetR family. Several of these genes are located immediately upstream of operons encoding functionally important c-type cytochromes. Computational analyses identified the presence of conserved promoters and other regulatory binding sites upstream of several G. sulfurreducens tetR genes. This suggests the possibility of an intermediary role of TetR family proteins in Geobacteraceae in regulatory cascades involving a variety of sigma factors. In order to understand the role of the TetR regulatory family in Geobacteraceae, we have inferred phylogenetic relationships among the Geobacteraceae TetR proteins and their homologs in other microbial species.},
	keywords = {Bacterial Proteins, Binding Sites, Gram-Negative Bacteria, Metals, Oxidation-Reduction, Phylogeny, Promoter Regions, Genetic, Sigma Factor},
	issn = {1557-8100},
	doi = {10.1089/omi.2010.0117},
	author = {Krushkal, Julia and Sontineni, Sreedhar and Leang, Ching and Qu, Yanhua and Adkins, Ronald M and Lovley, Derek R}
}
@article {537,
	title = {Regulation of two highly similar genes, omcB and omcC, in a 10 kb chromosomal duplication in Geobacter sulfurreducens.},
	journal = {Microbiology},
	volume = {151},
	year = {2005},
	month = {2005 Jun},
	pages = {1761-7},
	abstract = {The Fe(III)-reducing micro-organism Geobacter sulfurreducens requires an outer-membrane c-type cytochrome, OmcB, for Fe(III) reduction, but a related cytochrome, OmcC, which is 73 \% identical to OmcB, is not required. The omcB and omcC genes are part of a tandem chromosomal duplication consisting of two repeated clusters of four genes. The 2.7 kb sequences preceding omcB and omcC are identical with the exception of a single base pair change. Studies that combined genetic, Northern blotting and primer extension analyses demonstrated that both omcB and omcC are transcribed as monocistronic and polycistronic (orf1-orf2-omcB/omcC) transcripts. All of the promoters for the various transcripts were found to be located within the 2.7 kb identical region upstream of omcB and omcC. The sequences of the promoter regions for the two monocistronic transcripts are identical and equidistant from the omcB or omcC start codons. The promoters for the two polycistronic transcripts, in contrast, are distinct. One is specific for transcription of orf1-orf2-omcB and the other is associated with transcription of orf1-orf2-omcC. Studies with an RpoS-deficient mutant suggested that transcription from all four promoters is RpoS dependent under one or more growth conditions. Deletion of orfR, a gene immediately upstream of orf1-orf2-omcB that encodes a putative transcriptional regulator, significantly lowered the omcB transcription when Fe(III) was the electron acceptor and partially inhibited Fe(III) reduction. In contrast, levels of omcC transcripts were unaffected in the orfR mutant. These results indicate that omcB and omcC operons represent a rare instance in which duplicated operons, located in tandem on the chromosome, have different transcriptional regulation.},
	keywords = {Bacterial Outer Membrane Proteins, Bacterial Proteins, Blotting, Northern, DNA, Bacterial, Gene Deletion, Gene Expression Regulation, Bacterial, Geobacter, Molecular Sequence Data, Operon, Promoter Regions, Genetic, RNA, Bacterial, RNA, Messenger, Sequence Analysis, DNA, Sigma Factor, Transcription, Genetic},
	issn = {1350-0872},
	doi = {10.1099/mic.0.27870-0},
	author = {Leang, Ching and Lovley, Derek R}
}
