5n7y | pdb_00005n7y
Solution structure of B. subtilis Sigma G inhibitor CsfB
Structural highlights
Function[GIN_BACSU] An anti-sigma-G factor, prevents premature activation of sigma-G factor in the forespore; overexpression leads to 1000-fold reduction in spore formation, spore formation stops after engulfment (PubMed:17921305, PubMed:19497328). Overexpression also inhibits sigma-G transcription activation activity (PubMed:18208527). When both Gin and sigma-G are expressed in E.coli Gin inhibits sigma-G, strongly suggesting Gin inhibits by direct physical interaction (PubMed:19497328).[1] [2] [3] Publication Abstract from PubMedGlobal changes in bacterial gene expression can be orchestrated by the coordinated activation/deactivation of alternative sigma (sigma) 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, sigma(G) and sigma(E), during spore formation by Bacillus subtilis. CsfB assembles into a symmetrical homodimer, with each monomer bound to a single Zn(2+) ion via a treble-clef zinc finger fold. Directed mutagenesis indicates that dimer formation is critical for CsfB-mediated inhibition of both sigma(G) and sigma(E), and we have characterized these interactions in vitro. This work represents an advance in our understanding of how CsfB mediates inhibition of two alternative sigma factors to drive developmental gene expression in a bacterium. Structural and Functional Insights into Bacillus subtilis Sigma Factor Inhibitor, CsfB.,Martinez-Lumbreras S, Alfano C, Evans NJ, Collins KM, Flanagan KA, Atkinson RA, Krysztofinska EM, Vydyanath A, Jackter J, Fixon-Owoo S, Camp AH, Isaacson RL Structure. 2018 Mar 3. pii: S0969-2126(18)30047-9. doi:, 10.1016/j.str.2018.02.007. PMID:29526435[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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