Studies of SpoIIAB mutant proteins elucidate the mechanisms that regulate the developmental transcription factor sigmaF in Bacillus subtilis.

ABSTRACT: SigmaF, the first compartment-specific sigma factor of sporulation, is regulated by an anti-sigma factor, SpoIIAB (AB) and its antagonist SpoIIAA (AA). AB can bind to sigmaF in the presence of ATP or to AA in the presence of ADP; in addition, AB can phosphorylate AA. The ability of AB to switch between its two binding partners regulates sigmaF. Early in sporulation, AA activates sigmaF by releasing it from its complex with AB. We have previously proposed a reaction scheme for the phosphorylation of AA by AB which accounts for AA's regulatory role. A crucial feature of this scheme is a conformational change in AB that accompanies its switch in binding partner. In the present study, we have studied three AB mutants, all of which have amino-acid replacements in the nucleotide-binding region;

SUBMITTER: Shu JC 

PROVIDER: S-EPMC1134100 | biostudies-literature | 2004 Nov

REPOSITORIES: biostudies-literature