L-cysteinyl-[cysteine desulfurase] + L-cysteine <=> S-sulfanyl-L-cysteinyl-[cysteine desulfurase] + L-alanine
l-cysteinyl-[cysteine desulfurase] + l-cysteine <=> s-sulfanyl-l-cysteinyl-[cysteine desulfurase] + l-alanine