May be involved in the ESX-1 / type VII specialized secretion system (T7SS), which exports several proteins including EsxA and EsxB (Probable). Involved in DNA conjugation in the recipient strain (PubMed:18554329). Loss of DNA conjugation when disrupted in recipient strain; strain still secretes EsxB (PubMed:18554329). In the well characterized mc(2)155 strain this gene is interrupted and its 5' end is replaced; the last third of the protein is nearly identical in both strains (from residue 468 on in this entry). DNA conjugation in M.smegmatis is unidirectional with distinct donor and recipient strains; mc(2)155 is a donor strain while MKD8 is a recipient strain. Mutations in a donor strain that alter DNA transfer do not always alter DNA transfer in a recipient strain. Truncated N-terminus.