RRC ID 4989
Author Sinha S, Cameron AD, Redfield RJ.
Title Sxy induces a CRP-S regulon in Escherichia coli.
Journal J. Bacteriol.
Abstract Escherichia coli is not considered naturally competent, yet it has homologues of the genes that most competent bacteria use for DNA uptake and processing. In Haemophilus influenzae and Vibrio cholerae, these genes are regulated by the Sxy and cyclic AMP receptor (CRP) proteins. We used microarrays to find out whether similar regulation occurs in E. coli. Expression of sxy strongly induced 63 transcriptional units, 34 of which required CRP for transcriptional activation and had promoter sites resembling the Sxy- and CRP-dependent CRP-S motif previously characterized in H. influenzae. As previously reported, sxy expression also induced the sigma-H regulon. Flagellar operons were downregulated by sxy expression, although motility remained unaffected. The CRP-S regulon included all of E. coli's known competence gene homologues, so we investigated Sxy's effect on competence-associated phenotypes. A sxy knockout reduced both "natural" plasmid transformation and competitive fitness in long-term culture. In addition, expression of plasmid-borne sxy led to production of type IV pilin, the main subunit of the DNA uptake machinery of most bacteria. Although H. influenzae Sxy only weakly activated the E. coli Sxy regulon, induction was dramatically improved when it was coexpressed with its cognate CRP, suggesting that intimate interactions between Sxy and CRP are required for transcriptional activation at CRP-S sites.
Volume 191(16)
Pages 5180-95
Published 2009-8
DOI 10.1128/JB.00476-09
PII JB.00476-09
PMID 19502395
PMC PMC2725579
MeSH Bacterial Proteins / genetics Bacterial Proteins / physiology Escherichia coli / genetics* Escherichia coli Proteins / genetics Escherichia coli Proteins / physiology* Fimbriae Proteins / genetics Fimbriae Proteins / metabolism Flagella / genetics Gene Expression Regulation, Bacterial / genetics Gene Expression Regulation, Bacterial / physiology Genetic Complementation Test Microscopy, Electron, Transmission Oligonucleotide Array Sequence Analysis Operon / genetics Phenotype Polymerase Chain Reaction Receptors, Cyclic AMP / genetics* Regulon / genetics* Trans-Activators / genetics Trans-Activators / physiology
IF 3.219
Times Cited 21
Prokaryotes E. coli ME9062(BW25113) JW0942 JW3778 JW5702 JW1908