Genome diversity of the TetR family of transcriptional regulators in a metal-reducing bacterial family Geobacteraceae and other microbial species.

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 ...