An epigenetic switch involving overlapping fur and DNA methylation optimizes expression of a type VI secretion gene cluster.

ABSTRACT: Type VI secretion systems (T6SS) are macromolecular machines of the cell envelope of Gram-negative bacteria responsible for bacterial killing and/or virulence towards different host cells. Here, we characterized the regulatory mechanism underlying expression of the enteroagregative Escherichia coli sci1 T6SS gene cluster. We identified Fur as the main regulator of the sci1 cluster. A detailed analysis of the promoter region showed the presence of three GATC motifs, which are target of the DNA adenine methylase Dam. Using a combination of reporter fusion, gel shift, and in vivo and in vitro Dam methylation assays, we dissected the regulatory role of Fur and Dam-dependent methylation. We showed that the sci1 gene cluster expression is under the control of an epigenetic switch depending on me

SUBMITTER: Brunet YR 

PROVIDER: S-EPMC3145626 | biostudies-literature | 2011 Jul

REPOSITORIES: biostudies-literature