This proteins are involved in transferring a group of integrating conjugative DNA elements, such as pSAM2 from Streptomyces ambofaciens ([1]). Their precise role is not known.

1: Transfer functions of the conjugative integrating element pSAM2 from Streptomyces ambofaciens: characterization of a kil-kor system associated with transfer. Hagege J, Pernodet JL, Sezonov G, Gerbaud C, Friedmann A, Guerineau M; J Bacteriol 1993;175:5529-5538. PMID:8366038

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