Gene encoding two alkali-soluble components of the spore coat from Bacillus subtilis

We report the cloning and characterization of a gene called cotF from Bacillus subtilis that encodes alkali-soluble polypeptides of 5 and 8 kDa that are components of the spore coat. The 5- and 8-kDa polypeptides are generated by proteolytic cleavage of the primary product of the cotF gene, which is 160 codons in length and is capable of encoding a polypeptide of 19 kDa. Amino acid sequence analysis indicates that the 5-kDa species is derived from the NH2-terminal portion of the primary gene product and that the 8-kDa species is derived from the COOH-terminal portion. A mutant bearing an in vitro-constructed cotF null mutation produced normal-looking spores that contained an apparently complete set of coat proteins except for the absence of the 5- and 8-kDa polypeptides. The map position of cotF is 349 degrees. Transcription of cotF commenced coincidently (during h 6 of sporulation) with genes known to be under the control of sporulation transcription factor sigma kappa.