preferred_name: L-arginyl-[methyl-coenzyme M reductase] + AH2 + 2 S-adenosyl-L-methionine => (5S)-C-methyl-L-arginyl-[methyl-coenzyme M reductase] + 5'-deoxyadenosine + L-methionine + A + S-adenosyl-L-homocysteine + 2 H(+)