Isolation of a Bacillus subtilis spoIIGA allele that suppresses processing-negative mutations in the Pro-σ(E) gene (sigE)

σ(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- σ(E)). A mutation which facilitates the conversion of inefficiently processed Pro-σ(E) variants into mature σ(E) was identified and mapped to spoIIGA. The isolation of such a mutation argues that SpoIIGA is directly involved in the Pro-σ(E) processing reaction.