(sulfur carrier)-SH + L-alanine => (sulfur carrier)-H + L-cysteine
(sulfur carrier)-sh + l-alanine => (sulfur carrier)-h + l-cysteine
(sulfur carrier)-SH + L-alanine => (sulfur carrier)-H + L-cysteine
(sulfur carrier)-sh + l-alanine => (sulfur carrier)-h + l-cysteine