Expression of a cryptic secondary sigma factor gene unveils natural competence for DNA transformation in Staphylococcus aureus.

ABSTRACT: It has long been a question whether Staphylococcus aureus, a major human pathogen, is able to develop natural competence for transformation by DNA. We previously showed that a novel staphylococcal secondary sigma factor, SigH, was a likely key component for competence development, but the corresponding gene appeared to be cryptic as its expression could not be detected during growth under standard laboratory conditions. Here, we have uncovered two distinct mechanisms allowing activation of SigH production in a minor fraction of the bacterial cell population. The first is a chromosomal gene duplication rearrangement occurring spontaneously at a low frequency [≤10(-5)], generating expression of a new chimeric sigH gene. The second involves post-transcriptional regulation through an upstream

SUBMITTER: Morikawa K 

PROVIDER: S-EPMC3486894 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature