The divergent cts1 type VI secretion system locus of Citrobacter rodentium is controlled by multiple promoters that are silenced by H-NS, with CpxR contributing to their activation upon derepression

Graphical Abstract

The CTS1 type VI secretion system of Citrobacter rodentium is organized into the divergent clusters: cts1L and cts1R . Multiple promoters coordinate cts1 expression: four are located in the divergent regulatory region, and four additional promoters reside within cts1R . cts1 is silenced by H-NS and activated by CpxR when repression is relieved.