A SMALL, STABLE RNA INDUCED BY OXIDATIVE STRESS - ROLE AS A PLEIOTROPIC REGULATOR AND ANTIMUTATOR

Exposure of E. coli to hydrogen peroxide induces the transcription of a small RNA denoted oxyS. The oxyS RNA is stable, abundant, and does n ot encode a protein. oxyS activates and represses the expression of nu merous genes in E. coli, and eight targets, including genes encoding t he transcriptional regulators FhlA and sigma(s), were identified. oxyS expression also leads to a reduction in spontaneous and chemically-in duced mutagenesis. Our results suggest that the oxyS RNA acts as a reg ulator that integrates adaptation to hydrogen peroxide with other cell ular stress responses and helps to protect cells against oxidative dam age.