... processing unit Fig E2 and E3BP domains and their binding interactions E2 subunit domains: L1, N-terminal lipoyl domain; L2, inner lipoyl domain; B, E1 binding domain; I, oligomer-forming, acetyl-transferase-catalyzing ... L2 In a second region at the other end of the L2 domain, mutation of glutamates 16 2, 17 9 and 18 2, and glutamine 18 1 greatly reduces binding Indeed, substitution of alanine or glutamine for Glu182 ... acetyl-transferase-catalyzing inner domain E3BP domains: L3, N-terminal lipoyl domain; B, E3 binding domain; I, inner domain which associates with the inner domain of E2 Dotted connections indicate binding interactions...