This large family of proteins contains several highly conserved charged amino acids, suggesting this may be an enzymatic domain (Bateman A pers. obs). The family includes SanA Swiss:P33017 that is involved in Vancomycin resistance [1]. This protein may be involved in murein synthesis [2].

1: Amplification of a novel gene, sanA, abolishes a vancomycin-sensitive defect in Escherichia coli. Rida S, Caillet J, Alix JH; J Bacteriol 1996;178:94-102. PMID:8550448

2: The sfiX, rfe and metN genes of Salmonella typhimurium and their involvement in the His(c) pleiotropic response. Mouslim C, Cano DA, Casadesus J; Mol Gen Genet 1998;259:46-53. PMID:9738879