Sporulation regulator, sensor kinase SpoOB-type, helix hairpin <p> 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 [<cite idref="PUB00042582"/>].</p><p>SpoOB has an alpha-beta core structure that resembles the histidine kinase fold, but lacks the kinase ATP-binding site [<cite idref="PUB00028707"/>]. This entry represents a helix hairpin domain found at the N-terminal of SpoOB, as well as in other sensor kinases.</p>