CroS_R391 , an ortholog of the λ Cro repressor, plays a major role in suppressing polV_R391 -dependent mutagenesis.

ABSTRACT: When subcloned into low-copy-number expression vectors, rumAB, encoding polV_R391 (RumA'₂ B), is best characterized as a potent mutator giving rise to high levels of spontaneous mutagenesis in vivo. This is in dramatic contrast to the poorly mutable phenotype when polV_R391 is expressed from the native 88.5 kb R391, suggesting that R391 expresses cis-acting factors that suppress the expression and/or the activity of polV_R391 . Indeed, we recently discovered that SetR_R391 , an ortholog of λ cI repressor, is a transcriptional repressor of rumAB. Here, we report that CroS_R391 , an ortholog of λ Cro, also serves as a potent transcriptional repressor of rumAB. Levels of RumA are dependent upon an interplay between SetR_R391

SUBMITTER: McDonald JP 

PROVIDER: S-EPMC8460599 | biostudies-literature | 2021 Sep

REPOSITORIES: biostudies-literature