An ATPase (shown for residues 72-479) (PubMed:26396239). Part of the ESX-1 / type VII specialized secretion system (T7SS), which exports several proteins including EsxA and EsxB (PubMed:15687187). Plays a role in DNA conjugation, in both donor and recipient strains (PubMed:15314236). Part of the ESX-1 / type VII secretion system (T7SS), which is composed of cytosolic and membrane components. The ESX-1 membrane complex is composed of EccB1, EccCa1, EccCb1, EccD1 and EccE1 (By similarity). Has a discontinuous central core of beta sheets stabilized by a disulfide bond that is flanked by 2 structural domain repeats on each side; the protein forms an elongated 'S'-shaped structure (PubMed:26922638). Increases efficiency of DNA conjugation when disrupted in donor strain (PubMed:15314236). Loss of secretion of EsxA and EsxB, but not their expression (PubMed:15687187). 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. Belongs to the EccB family.