We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
PilR, a transcriptional regulator for pilin and other genes required for Fe(III) reduction in Geobacter sulfurreducens.
- Authors
Juárez, Katy; Kim, Byoung-Chan; Nevin, Kelly; Olvera, Leticia; Reguera, Gemma; Lovley, Derek R; Methé, Barbara A
- Abstract
Growth using Fe(III) as a terminal electron acceptor is a critical physiological process in Geobacter sulfurreducens. However, the mechanisms of electron transfer during Fe(III) reduction are only now being understood. It has been demonstrated that the pili in G. sulfurreducens function as microbial nanowires conducting electrons onto Fe(III) oxides. A number of c-type cytochromes have also been shown to play important roles in Fe(III) reduction. However, the regulatory networks controlling the expression of the genes involved in such processes are not well known. Here we report that the expression of pilA, which encodes the pilistructural protein, is directly regulated by a two-component regulatory system in which PilR functions as an RpoN-dependent enhancer binding protein. Surprisingly, a deletion of the pilR gene affected not only insoluble Fe(III) reduction, which requires pili, but also soluble Fe(III) reduction, which, in contrast, does not require pili. Gene expression profiling using whole-genome DNA microarray and quantitative RT-PCR analyses obtained with a PilR-deficient mutant revealed that the expression of pilA and other pilin-related genes are downregulated, while many c-type cytochromes involved in Fe(III) reduction were differentially regulated. This is the first instance of an enhancer binding protein implicated in regulating genes involved in Fe(III) respiratory functions.
- Publication
Journal of molecular microbiology and biotechnology, 2009, Vol 16, Issue 3-4, p146
- ISSN
1660-2412
- Publication type
Journal Article
- DOI
10.1159/000115849