The enzyme cysteine-S-conjugate β-lyase (EC 4.4.1.13) catalyzes the chemical reaction
| cysteine-S-conjugate β-lyase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 4.4.1.13 | ||||||||
| CAS no. | 68652-57-3 | ||||||||
| 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 / QuickGO | ||||||||
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- an L-cysteine-S-conjugate + H2O = a thiol + NH3 + pyruvate (overall reaction)
- (1a) an L-cysteine-S-conjugate = a thiol + 2-aminoprop-2-enoate
- (1b) 2-aminoprop-2-enoate = 2-iminopropanoate (spontaneous)
- (1c) 2-iminopropanoate + H2O = pyruvate + NH3 (spontaneous)
This enzyme belongs to the family of lyases, specifically the class of carbon-sulfur lyases. The systematic name of this enzyme class is L-cysteine-S-conjugate thiol-lyase (deaminating; pyruvate-forming). Other names in common use include cysteine conjugate β-lyase, glutamine transaminase K/cysteine conjugate β-lyase, and L-cysteine-S-conjugate thiol-lyase (deaminating). It employs one cofactor, pyridoxal phosphate.
Structural studies
editAs of late 2007, 3 structures have been solved for this class of enzymes, with PDB accession codes 1W7L, 1W7M, and 1W7N.
References
edit- Tateishi M, Suzuki S, Shimizu H (1978). "Cysteine conjugate β-lyase in rat liver. A novel enzyme catalyzing formation of thiol-containing metabolites of drugs". J. Biol. Chem. 253 (24): 8854–9. doi:10.1016/S0021-9258(17)34256-4. PMID 721818.
