Catalyzes the lipoylation of proteins, such as GcvH (SAV0833) and GcvH-L (SAV0324), likely via the ATP-dependent activation of lipoate to lipoyl-AMP and the transfer of the activated lipoyl onto the lipoyl domain of the target protein. (R)-lipoate + ATP + L-lysyl-[lipoyl-carrier protein] = (R)-N(6)-lipoyl-L-lysyl-[lipoyl-carrier protein] + AMP + diphosphate + H(+) Protein modification; protein lipoylation via exogenous pathway; protein N(6)-(lipoyl)lysine from lipoate: step 1/2. Protein modification; protein lipoylation via exogenous pathway; protein N(6)-(lipoyl)lysine from lipoate: step 2/2.