Threonine ammonia-lyase

From Wikipedia, the free encyclopedia

In enzymology, a threonine ammonia-lyase (EC 4.3.1.19) is an enzyme that catalyzes the chemical reaction

L-threonine $\rightleftharpoons$ 2-oxobutanoate + NH₃

Hence, this enzyme has one substrate, L-threonine, and two products, 2-oxobutanoate and NH₃.

This enzyme belongs to the family of lyases, specifically ammonia lyases, which cleave carbon-nitrogen bonds. The systematic name of this enzyme class is L-threonine ammonia-lyase (2-oxobutanoate-forming). Other names in common use include threonine deaminase, L-serine dehydratase, serine deaminase, L-threonine dehydratase, threonine dehydrase, L-threonine deaminase, threonine dehydratase, L-threonine hydro-lyase (deaminating), and L-threonine ammonia-lyase. This enzyme participates in glycine, serine and threonine metabolism and valine, leucine and isoleucine biosynthesis. It employs one cofactor, pyridoxal phosphate.

1 Structural studies
2 References
3 External links
- 3.1 Gene Ontology (GO) codes

[edit] Structural studies

As of late 2007, 4 structures have been solved for this class of enzymes, with PDB accession codes 1VE5, 2GN0, 2GN1, and 2GN2.

[edit] References

IUBMB entry for 4.3.1.19
BRENDA references for 4.3.1.19 (Recommended.)
PubMed references for 4.3.1.19
PubMed Central references for 4.3.1.19
Google Scholar references for 4.3.1.19
Cohn MS, Phillips AT (1974). "Purification and characterization of a B6-independent threonine dehydratase from Pseudomonas putida". Biochemistry. 13: 1208–14. doi:10.1021/bi00703a604. PMID 4814721.
NISHIMURA JS, GREENBERG DM (1961). "Purification and properties of L-threonine dehydrase of sheep liver". J. Biol. Chem. 236: 2684–91. PMID 14479973.
Phillips AT, Wood WA (1965). "The mechanism of action of 5'-adenylic acid-activated threonine dehydrase". J. Biol. Chem. 240: 4703–9. PMID 5321308.
Shizuta Y, Nakazawa A, Tokushige M, Hayaishi O (1969). "Studies on the interaction between regulatory enzymes and effectors 3. Crystallization and characterization of adenosine 5'-monophosphate-dependent threonine deaminase from Escherichia coli". J. Biol. Chem. 244: 1883–9. PMID 4889010.