Protein
Sporulation inhibitor sda
Organism
Bacillus subtilis (strain 168)
Function
Mediates a developmental checkpoint inhibiting initiation of sporulation (by preventing phosphorylation of spo0A) in response to defects in the replication initiation machinery. Inhibits autophosphorylation of the histidine protein kinase KinA, forming a molecular barricade that prevents productive interaction between the ATP-binding site in the catalytic domain and the phosphorylatable His in the phosphotransfer domain of KinA. Probably also inhibits the activity of KinB, but has relatively little effect on KinC. Has at least one target in vivo in addition to KinA as sda does not require KinA to inhibit sporulation.
Sequence
MNWVPSMRKLSDELLIESYFKATEMNLNRDFIELIENEIKRRSLGHIISVSS