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EMBO J. 1999 Aug 2;18(15):4292-8.

RsrA, an anti-sigma factor regulated by redox change.

Author information

1
Department of Microbiology, College of Natural Sciences, and Research Center for Molecular Microbiology, Seoul National University, Seoul 151-742, Korea.

Abstract

SigR (sigma(R)) is a sigma factor responsible for inducing the thioredoxin system in response to oxidative stress in the antibiotic-producing, Gram-positive bacterium Streptomyces coelicolor A3(2). Here we identify a redox-sensitive, sigma(R)-specific anti-sigma factor, RsrA, which binds sigma(R) and inhibits sigma(R)-directed transcription in vitro only under reducing conditions. Exposure to H(2)O(2) or to the thiol-specific oxidant diamide caused the dissociation of the sigma(R)-RsrA complex, thereby allowing sigma(R)-dependent transcription. This correlated with intramolecular disulfide bond formation in RsrA. Thioredoxin was able to reduce oxidized RsrA, suggesting that sigma(R), RsrA and the thioredoxin system comprise a novel feedback homeostasis loop that senses and responds to changes in the intracellular thiol-disulfide redox balance.

PMID:
10428967
PMCID:
PMC1171505
DOI:
10.1093/emboj/18.15.4292
[Indexed for MEDLINE]
Free PMC Article

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