Small domain family found in proteins of of unknown function. Some are secreted (e.g. Swiss:O25998) and implicated in motility in bacteria. Also occurs in Leishmania spp. as an essential gene. Over-expression in L.amazonensis increases virulence (Swiss:O43987; [1]). A pair of cysteine residues show correlated conservation, suggesting that they form a disulphide bond.

1: Leishmania: overexpression and comparative structural analysis of the stage-regulated meta 1 gene. Uliana SR, Goyal N, Freymuller E, Smith DF; Exp Parasitol 1999;92:183-191. PMID:10403759

2: New Knowledge from Old: In silico discovery of novel protein domains in Streptomyces coelicolor. Yeats C, Bentley S, Bateman A; BMC Microbiol 2003;3:3-3. PMID:12625841