Cystathionine beta-lyase
| cystathionine beta-lyase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Cystathionine beta-lyase tetramer, E.Coli | |||||||||
| Identifiers | |||||||||
| EC number | 4.4.1.8 | ||||||||
| CAS number | 9055-05-4 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / EGO | ||||||||
| |||||||||
In enzymology, a cystathionine beta-lyase (EC 4.4.1.8) is an enzyme that catalyzes the chemical reaction
- L-cystathionine + H2O L-homocysteine + NH3 + pyruvate
Thus, the two substrates of this enzyme are L-cystathionine and H2O, whereas its 3 products are L-homocysteine, NH3, and pyruvate.
This enzyme belongs to the family of lyases, specifically the class of carbon-sulfur lyases. The systematic name of this enzyme class is L-cystathionine L-homocysteine-lyase (deaminating; pyruvate-forming). Other names in common use include beta-cystathionase, cystine lyase, cystathionine L-homocysteine-lyase (deaminating), and L-cystathionine L-homocysteine-lyase (deaminating). This enzyme participates in 5 metabolic pathways: methionine metabolism, cysteine metabolism, selenoamino acid metabolism, nitrogen metabolism, and sulfur metabolism. It employs one cofactor, pyridoxal phosphate.
Structural studies
As of late 2007, 5 structures have been solved for this class of enzymes, with PDB accession codes 1CL1, 1CL2, 1IBJ, 2FQ6, and 2GQN.
References
- Anderson NW; Thompson JF (1979). "Cystine lyase: beta-cystathionase from turnip roots". Phytochemistry. 18 (12): 1953–1958. doi:10.1016/S0031-9422(00)82710-7.
- FLAVIN M, SLAUGHTER C (1964). "CYSTATHIONINE CLEAVAGE ENZYMES OF NEUROSPORA". J. Biol. Chem. 239: 2212–9. PMID 14209950.