Structural highlights
Function
[SP2AB_GEOSE] Binds to sigma F and blocks its ability to form an RNA polymerase holoenzyme (E-sigma F). Phosphorylates SpoIIAA on a serine residue. This phosphorylation may enable SpoIIAA to act as an anti-anti-sigma factor that counteracts SpoIIAB and thus releases sigma F from inhibition.[HAMAP-Rule:MF_00637] [O32728_GEOSE] Sigma factors are initiation factors that promote the attachment of RNA polymerase to specific initiation sites and are then released.[RuleBase:RU000715]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Cell type-specific transcription during Bacillus sporulation is established by sigmaF. SpoIIAB is an anti-sigma that binds and negatively regulates sigmaF, as well as a serine kinase that phosphorylates and inactivates the anti-anti-sigma SpoIIAA. The crystal structure of sigmaF bound to the SpoIIAB dimer in the low-affinity, ADP form has been determined at 2.9 A resolution. SpoIIAB adopts the GHKL superfamily fold of ATPases and histidine kinases. A domain of sigmaF contacts both SpoIIAB monomers, while 80% of the sigma factor is disordered. The interaction occludes an RNA polymerase binding surface of sigmaF, explaining the SpoIIAB anti-sigma activity. The structure also explains the specificity of SpoIIAB for its target sigma factors and, in combination with genetic and biochemical data, provides insight into the mechanism of SpoIIAA anti-anti-sigma activity.
Crystal structure of the Bacillus stearothermophilus anti-sigma factor SpoIIAB with the sporulation sigma factor sigmaF.,Campbell EA, Masuda S, Sun JL, Muzzin O, Olson CA, Wang S, Darst SA Cell. 2002 Mar 22;108(6):795-807. PMID:11955433[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Campbell EA, Masuda S, Sun JL, Muzzin O, Olson CA, Wang S, Darst SA. Crystal structure of the Bacillus stearothermophilus anti-sigma factor SpoIIAB with the sporulation sigma factor sigmaF. Cell. 2002 Mar 22;108(6):795-807. PMID:11955433
