Sporulation initiation phospho-transferase B, C-terminal
SMART accession number:SM01317
Description: Sporulation initiation phospho-transferase B or SpoOB is part of a phospho-relay that initiates sporulation in Bacillus subtilis. Spo0B is a two-domain protein consisting of an N-terminal alpha-helical hairpin domain and a C-terminal alpha/beta domain, represented by this family. Two subunits of Spo0B dimerise by a parallel association of helical hairpins to form a novel four-helix bundle from which the active histidine - involved in the auto-phosphorylation - protrudes. In the phospho-relay, the signal-receptor histidine kinases are dephosphorylated by a common response regulator, Spo0F. Spo0B then takes phosphorylated Spo0F as substrate hereby mediating the transfer of a phosphoryl group to Spo0A, the ultimate transcription factor.
Interpro abstract (IPR016122):

Response regulatory proteins such as sensor kinases control a variety of environmentally induced responses in bacteria. SpoOB is a response regulator that responds to nutritional stress by inducing sporulation. SpoOB is a phosphotransferase that acts upon SpoOA using SpoOF as the phosphor-donor. Phosphorylated SpoOA ca activate sporulation-specific gene transcription [ (PUBMED:1664534) ].

SpoOB has an alpha-beta core structure that resembles the histidine kinase fold, but lacks the kinase ATP-binding site [ (PUBMED:9809070) ]. This domain is found at the C teminus of SpoOB, as well as in other sensor kinases.

Family alignment:
View or

There are 146 SPOB_ab domains in 146 proteins in SMART's nrdb database.

Click on the following links for more information.