Identification of rocA, a positive regulator of covR expression in the group A streptococcus.

ABSTRACT: In the group A streptococcus (GAS; Streptococcus pyogenes), a two-component system known as CovRS (or CsrRS) regulates about 15% of the genes, including several important virulence factors like the hyaluronic acid capsule. Most of these genes, including covR itself, are negatively regulated by CovR. We have isolated two independent ISS1 insertions in an open reading frame (ORF) that increases CovR expression as measured by a Pcov-gusA reporter fusion in single copy in the GAS chromosome. This ORF, named rocA for "regulator of Cov," activates covR transcription about threefold. As expected, a rocA mutant is mucoid and produces more transcript from the has promoter since this promoter is repressed by CovR. This effect is dependent on the presence of a wild-type covR gene. In contrast to its

SUBMITTER: Biswas I 

PROVIDER: S-EPMC154078 | biostudies-literature | 2003 May

REPOSITORIES: biostudies-literature