This family of proteins is involved in sporulation. In B. subtilis its expression is regulated by the early mother-cell-specific transcription factor sigma-E [1].

1: Identification of sporulation genes by genome-wide analysis of the sigmaE regulon of Bacillus subtilis. Feucht A, Evans L, Errington J; Microbiology. 2003;149:3023-3034. PMID:14523133