This family contains the bacterial stage V sporulation protein AD (SpoVAD), which is approximately 340 residues long. This is one of six proteins encoded by the spoVA operon, which is transcribed exclusively in the forespore at about the time of dipicolinic acid (DPA) synthesis in the mother cell. The functions of the proteins encoded by the spoVA operon are unknown, but it has been suggested they are involved in DPA transport during sporulation [1].

1: The products of the spoVA operon are involved in dipicolinic acid uptake into developing spores of Bacillus subtilis. Tovar-Rojo F, Chander M, Setlow B, Setlow P; J Bacteriol 2002;184:584-587. PMID:11751839