A pyridoxal-phosphate protein. Dithiothreitol or 2-sulfanylethan-1-ol (2-mercaptoethanol) can act as the reducing agent in the reaction. The enzyme from animals does not act on cysteine, serine or chloroalanine [1,3], while the enzyme from bacteria shows activity with cysteine (cf. EC
2.8.1.7, cysteine desulfurase) [2].