ISOLATION OF A BACILLUS-SUBTILIS SPOIIGA ALLELE THAT SUPPRESSES PROCESSING-NEGATIVE MUTATIONS IN THE PRO-SIGMA(E) GENE (SIGE)

sigma(E), a sporulation-essential sigma factor of Bacillus subtilis, is formed by a developmentally regulated proteolysis which removes 27 to 29 amino acids from the amino terminus of an inactive precursor protein (Pro-sigma(E)). A mutation which facilitates the conversion of inefficiently processed Pro-sigma(E) variants into mature sigma(E) was identified and mapped to spoIIGA. The isolation of such a mutation argues that SpoIIGA is directly involved in the Pro-sigma(E) processing reaction.