Most enzymes that catalyse this reaction are pyridoxal-phosphate-dependent, although some enzymes contain an iron-sulfur cluster instead. The reaction catalysed by both types of enzymes involves the initial elimination of water to form an enamine intermediate (hence the enzyme's original classification as EC 184.108.40.206
, threonine dehydratase), followed by tautomerization to an imine form and hydrolysis of the C-N bond [3,5]. The latter reaction, which can occur spontaneously, is also be catalysed by EC 220.127.116.11
, 2-iminobutanoate/2-iminopropanoate deaminase . The enzymes from a number of sources also act on L-serine, cf. EC 18.104.22.168
, L-serine ammonia-lyase.