label: [sulfur-carrier protein]-S-sulfanyl-L-cysteine + [sulfur carrier]-H <=> [sulfur-carrier protein]-L-cysteine + [sulfur carrier]-SH
label_lc: [sulfur-carrier protein]-s-sulfanyl-l-cysteine + [sulfur carrier]-h <=> [sulfur-carrier protein]-l-cysteine + [sulfur carrier]-sh