<p>This entry represents RNA polymerase sporulation-specific sigma factors, including SigK and SigE. Sigma factors are initiation factors that promote the attachment of RNA polymerase to specific initiation sites and are then released. This sigma factor is responsible for the expression of sporulation specific genes. Gene regulation during Bacillus sporulation involves the activation and inactivation of multiple sigma subunits of RNA polymerase in a cascade. In the mother cell compartment of sporulating Bacillus cells, expression of the sigE gene, encoding the earlier-acting sigma factor, sigmaE, is negatively regulated by the later-acting sigma factor, sigmaK [<cite idref="PUB00042716"/>].</p> RNA polymerase sporulation-specific sigma factor, SigK/SigE