RNA polymerase sigma-H factor <p>This entry represents RNA polymerase sigma-H factor found in bacteria. Sigma factors are initiation factors that promote the attachment of RNA polymerase to specific initiation sites and are then released. The major sigma factor in most bacteria is sigma-A. Sigma-H, the sigH (spo0H) gene product, directs the transcription of several genes that function in the transition from exponential growth to stationary phase, including the initiation of spore formation and entry into the state of genetic competence [<cite idref="PUB00042715"/>].</p>