Cystathionine beta-lyase

Cystathionine beta-lyase
cystathionine beta-lyase
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 \rightleftharpoons 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 and 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. 
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