(GenBank) Lipoyltransferase (EC 2.3.1.-) (Lipoyl-[acyl-carrier protein]-protein -N-lipoyltransferase) (Lipoate-protein ligase B).,Catalyzes the transfer of the endogenously synthesized lipoate to apoproteins creating an amide linkage that joins the free carboxyl group of lipoic acid to the epsilon-amino group of a specific lysine residue in lipoate-dependent enzymes. Utilizes lipoyl-acyl-carrier protein as a source of lipoyl groups although octanoyl groups from octanoyl-ACP can also be transferred to the lipoyl domain of apoproteins (By similarity).