SpoIIAB is an anti-sigma factor that binds to and inhibits transcription by regulatory protein sigma F from Bacillus subtilis.

• DOI: 10.1073/pnas.90.6.2325
• Publication Date: 2006-05-31T12:41:16Z
• Authors: L Duncan; R Losick
• Keywords: Spores, Bacterial; 0301 basic medicine; Base Sequence; Transcription, Genetic; Molecular Sequence Data; Sigma Factor; Gene Expression Regulation, Bacterial; 03 medical and health sciences; Bacterial Proteins; Oligodeoxyribonucleotides; Genes, Bacterial; Operon; Escherichia coli; Mutagenesis, Site-Directed; Cloning, Molecular; Bacillus subtilis; Transcription Factors

The sigma F factor is a regulatory protein that is responsible for directing gene expression in the forespore compartment of developing cells of the spore-forming soil bacterium Bacillus subtilis. The sigma F factor is encoded by the promoter-distal member of sporulation operon spoIIA, which consists of cistrons called spoIIAA, spoIIAB, and spoIIAC. Genetic evidence indicates that the activity of sigma F is negatively regulated by the product (SpoIIAB) of the spoIIAB cistron. We now report that SpoIIAB is capable of binding to sigma F and inhibiting its capacity to direct transcription by core RNA polymerase from the promoter for a forespore-expressed gene. SpoIIAB is an anti-sigma factor that may be directly involved in the compartmentalization of sigma F-directed gene expression.