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 22.214.171.124
, 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 126.96.36.199
, 2-iminobutanoate/2-iminopropanoate deaminase . The enzymes from a number of sources also act on L-serine, cf. EC 188.8.131.52
, L-serine ammonia-lyase.