(2R,3R,5S,6R)-6-(ethyl)-2-(S-pantetheinyl)-carbapenam-3-carboxylate + cob(III)alamin + 5'-deoxyadenosine + L-methionine => (2R,3R,5S,6R)-6-(methyl)-2-(S-pantetheinyl)-carbapenam-3-carboxylate + methylcob(III)alamin + S-adenosyl-L-methionine
(2r,3r,5s,6r)-6-(ethyl)-2-(s-pantetheinyl)-carbapenam-3-carboxylate + cob(iii)alamin + 5'-deoxyadenosine + l-methionine => (2r,3r,5s,6r)-6-(methyl)-2-(s-pantetheinyl)-carbapenam-3-carboxylate + methylcob(iii)alamin + s-adenosyl-l-methionine