Genome-wide gene regulation of biosynthesis and energy generation by a novel transcriptional repressor in Geobacter species.

TitleGenome-wide gene regulation of biosynthesis and energy generation by a novel transcriptional repressor in Geobacter species.
Publication TypeJournal Article
Year of Publication2010
AuthorsUeki T, Lovley DR
JournalNucleic Acids Res
Volume38
Issue3
Pagination810-21
Date Published2010 Jan
ISSN1362-4962
KeywordsBacterial Proteins, Base Sequence, Citrate (si)-Synthase, Gene Expression Regulation, Bacterial, Genome, Bacterial, Geobacter, Molecular Sequence Data, Promoter Regions, Genetic, Repressor Proteins, Transcription, Genetic
Abstract

Geobacter species play important roles in bioremediation of contaminated environments and in electricity production from waste organic matter in microbial fuel cells. To better understand physiology of Geobacter species, expression and function of citrate synthase, a key enzyme in the TCA cycle that is important for organic acid oxidation in Geobacter species, was investigated. Geobacter sulfurreducens did not require citrate synthase for growth with hydrogen as the electron donor and fumarate as the electron acceptor. Expression of the citrate synthase gene, gltA, was repressed by a transcription factor under this growth condition. Functional and comparative genomics approaches, coupled with genetic and biochemical assays, identified a novel transcription factor termed HgtR that acts as a repressor for gltA. Further analysis revealed that HgtR is a global regulator for genes involved in biosynthesis and energy generation in Geobacter species. The hgtR gene was essential for growth with hydrogen, during which hgtR expression was induced. These findings provide important new insights into the mechanisms by which Geobacter species regulate their central metabolism under different environmental conditions.

DOI10.1093/nar/gkp1085
Alternate JournalNucleic Acids Res.
PubMed ID19939938