additional information |
mutation of a prominent surface loop that links the first and second beta-strands in all lipoyl domains, of E2 dihydrolipoyl acetyltransferase. Deletion of the loop (four residues) renders the domain incapable of reductive acetylation by pyruvate dehydrogenase complex subunit E1p in the presence of pyruvate. Additional exchange of the two residues on the C-terminal side of the loop (V14A, E15T) has no effect. Exchanging the residue on the N-terminal side of the lipoyl-lysine beta-turn in the E2p and E2o domains (G39T), both singly and in conjunction with the loop exchange, has no effect on the ability of the E2p domain to be reductively acetylated but does confer a slight increase in susceptibility to reductive succinylation. All mutant E2p domains, apart from that with the loop deletion, are readily lipoylated in vitro by lipoate protein ligase A |
Escherichia coli |