preferred_name: N(6)-L-threonylcarbamoyladenosine(37) in tRNA + [sulfur carrier]-SH + AH2 + S-adenosyl-L-methionine => 2-sulfanyl-N(6)-L-threonylcarbamoyladenosine(37) in tRNA + [sulfur carrier]-H + 5'-deoxyadenosine + L-methionine + A + H(+)