We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Extensive functional overlap between σ factors in Escherichia coli.
- Authors
Wade, Joseph T.; Roa, Daniel Castro; Grainger, David C.; Hurd, Douglas; Busby, Stephen J. W.; Struhl, Kevin; Nudler, Evgeny
- Abstract
Bacterial core RNA polymerase (RNAP) must associate with a σ factor to recognize promoter sequences. Escherichia coli encodes seven σ factors, each believed to be specific for a largely distinct subset of promoters. Using microarrays representing the entire E. coli genome, we identify 87 in vivo targets of σ32, the heat-shock σ factor, and estimate that there are 120–150 σ32 promoters in total. Unexpectedly, 25% of these σ32 targets are located within coding regions, suggesting novel regulatory roles for σ32. The majority of σ32 promoter targets overlap with those of σ70, the housekeeping σ factor. Furthermore, their DNA sequence motifs are often interdigitated, with RNAPσ70 and RNAPσ32 initiating transcription in vitro with similar efficiency and from identical positions. σE-regulated promoters also overlap extensively with those for σ70. These results suggest that extensive functional overlap between σ factors is an important phenomenon.
- Subjects
BACTERIAL genetics; ESCHERICHIA coli; RNA polymerases; GENE expression; NUCLEOTIDE sequence; CARRIER proteins
- Publication
Nature Structural & Molecular Biology, 2006, Vol 13, Issue 9, p806
- ISSN
1545-9993
- Publication type
Article
- DOI
10.1038/nsmb1130