EC 18.104.22.168 - L-serine ammonia-lyase
IntEnz Enzyme Nomenclature
L-serine hydro-lyase (deaminating)
- (1) L-serine = pyruvate + NH3
- (1a) L-serine = 2-aminoprop-2-enoate + H2O
- (1b) 2-aminoprop-2-enoate = 2-iminopropanoate (spontaneous)
- (1c) 2-iminopropanoate + H2O = pyruvate + NH3 (spontaneous)
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, L-serine dehydratase), followed by tautomerization to an imine form and hydrolysis of the C-N bond. The latter reaction, which can occur spontaneously, is also be catalysed by EC 126.96.36.199, 2-iminobutanoate/2-iminopropanoate deaminase. This reaction is also carried out by EC 188.8.131.52, threonine ammonia-lyase, from a number of sources.
Links to other databases
Occurrence of a catabolic L-serine (L-threonine) deaminase in Saccharomyces cerevisiae.Eur. J. Biochem. 123: 571-576 (1982). [PMID: 7042346]
L-Serine dehydratase from rat liver. Purification and some properties.Biochim. Biophys. Acta 321: 361-368 (1973). [PMID: 4750769]
L-Serine dehydratase (rat liver).Methods Enzymol. 17B: 346-351 (1971).
E. L-Serine dehydratase (Clostridium acidiurica).Methods Enzymol. 17B: 351-566 (1971).
L-Serine dehydratase (Escherichia coli).Methods Enzymol. 17B: 356-360 (1971).
Bacterial L-serine dehydratases: a new family of enzymes containing iron-sulfur clusters.Trends Biochem. Sci. 18: 297-300 (1993). [PMID: 8236444]
Crystal structure of serine dehydratase from rat liver.Biochemistry 42: 12854-12865 (2003). [PMID: 14596599]
[EC 184.108.40.206 created 1961 as EC 220.127.116.11, transfered 2001 to EC 18.104.22.168, modified 2014]