Format

Send to

Choose Destination
Microbiology. 2010 Aug;156(Pt 8):2470-83. doi: 10.1099/mic.0.039131-0. Epub 2010 May 13.

Regulation of the Escherichia coli csgD promoter: interplay between five transcription factors.

Author information

1
Department of Frontier Bioscience, Hosei University, Koganei, Tokyo 184-8584, Japan.

Abstract

Under stressful conditions in nature, Escherichia coli forms biofilms for long-term survival. Curli fimbriae are an essential architecture for cell-cell contacts within biofilms. Structural components and assembly factors of curli are encoded by two operons, csgBA and csgDEFG. The csgD gene product controls transcription of both operons. Reflecting the response of csgD expression to external stresses, a number of transcription factors participate in the regulation of the csgD promoter. Analysis of the csgD mRNA obtained from E. coli mutants in different transcription factors indicated that CpxR and H-NS act as repressors while OmpR, RstA and IHF act as activators. An acid-stress response regulator, RstA, activates csgD only under acidic conditions. These five factors bind within a narrow region of about 200 bp upstream of the csgD promoter. After pair-wise promoter-binding assays, the increase in csgD transcription in the stationary phase was suggested to be due, at least in part, to the increase in IHF level cancelling the silencing effect of H-NS. In addition, we propose a novel regulation model of this complex csgD promoter through cooperation between the two positive factors (OmpR-IHF and RstA-IHF) and also between the two negative factors (CpxR-H-NS).

PMID:
20466769
DOI:
10.1099/mic.0.039131-0
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Ingenta plc
Loading ...
Support Center