Catalyzes the amidotransfer (transamidation) of the octanoyl moiety from octanoyl-GcvH to the lipoyl domain of the E2 subunit of lipoate-dependent enzymes. L-lysyl-[lipoyl-carrier protein] + N(6)-octanoyl-L-lysyl-[glycine-cleavage complex H protein] = L-lysyl-[glycine-cleavage complex H protein] + N(6)-octanoyl-L-lysyl-[lipoyl-carrier protein] Protein modification; protein lipoylation via endogenous pathway; protein N(6)-(lipoyl)lysine from octanoyl-[acyl-carrier-protein]. The reaction proceeds via a thioester-linked acyl-enzyme intermediate. Belongs to the octanoyltransferase LipL family.