Part of the ABC transporter complex LktBD involved in leukotoxin export. Transmembrane domains (TMD) form a pore in the inner membrane and the ATP-binding domain (NBD) is responsible for energy generation (Probable). ATP + H2O + proteinSide 1 = ADP + phosphate + proteinSide 2. Homodimer. In LktB the peptidase C39 domain, the ATP-binding domain (NBD) and the transmembrane domain (TMD) are fused. Belongs to the ABC transporter superfamily. Protein-1 exporter (TC 3.A.1.109) family. Leu-10 is present instead of the conserved Cys which is expected to be the active site residue of peptidase C39. Thus this protein is presumed to be without peptidase activity.