Structural and Functional Insights into Bacillus subtilis Sigma Factor Inhibitor, CsfB.

ABSTRACT: Global changes in bacterial gene expression can be orchestrated by the coordinated activation/deactivation of alternative sigma (σ) factor subunits of RNA polymerase. Sigma factors themselves are regulated in myriad ways, including via anti-sigma factors. Here, we have determined the solution structure of anti-sigma factor CsfB, responsible for inhibition of two alternative sigma factors, σ^G and σ^E, during spore formation by Bacillus subtilis. CsfB assembles into a symmetrical homodimer, with each monomer bound to a single Zn²⁺ ion via a treble-clef zinc finger fold. Directed mutagenesis indicates that dimer formation is critical for CsfB-mediated inhibition of both σ^G and σ^E, and we have characterized these interactions in vitro. This

SUBMITTER: Martinez-Lumbreras S 

PROVIDER: S-EPMC5890618 | biostudies-literature | 2018 Apr

REPOSITORIES: biostudies-literature