This is a family of unknown function. However, family members such as yjcZ has been shown to be sporulation specific and transcribed by the SigK RNA polymerase beginning at t4 of sporulation [1].

1: Bacillus subtilis spoVIF (yjcC) gene, involved in coat assembly and spore resistance. Kuwana R, Yamamura S, Ikejiri H, Kobayashi K, Ogasawara N, Asai K, Sadaie Y, Takamatsu H, Watabe K; Microbiology. 2003;149:3011-3021. PMID:14523132