Biology:Homocysteine desulfhydrase
From HandWiki
Short description: Enzyme
| homocysteine desulfhydrase | |||||||||
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| Identifiers | |||||||||
| EC number | 4.4.1.2 | ||||||||
| CAS number | 9024-41-3 | ||||||||
| 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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The enzyme homocysteine desulfhydrase (EC 4.4.1.2) catalyzes the chemical reaction
- L-homocysteine + H2O = hydrogen sulfide + NH3 + 2-oxobutanoate (overall reaction)
- (1a) L-homocysteine = hydrogen sulfide + 2-aminobut-2-enoate
- (1b) 2-aminobut-2-enoate = 2-iminobutanoate (spontaneous)
- (1c) 2-iminobutanoate + H2O = 2-oxobutanoate + 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-homocysteine hydrogen-sulfide-lyase (deaminating; 2-oxobutanoate-forming). Other names in common use include homocysteine desulfurase, L-homocysteine hydrogen-sulfide-lyase (deaminating). This enzyme participates in nitrogen and sulfur metabolism. It employs one cofactor, pyridoxal phosphate.
References
- "Function of pyridoxal phosphate in desulfhydrase systems of Proteus morganii". The Journal of Biological Chemistry 192 (1): 371–7. September 1951. doi:10.1016/S0021-9258(18)55941-X. PMID 14917685.
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