|
Your query returned 1 entry. Printable version
EC | 4.4.1.2 | ||
Accepted name: | homocysteine desulfhydrase | ||
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) |
||
For diagram of reaction mechanism, click here | |||
Other name(s): | homocysteine desulfurase; L-homocysteine hydrogen-sulfide-lyase (deaminating) | ||
Systematic name: | L-homocysteine hydrogen-sulfide-lyase (deaminating; 2-oxobutanoate-forming) | ||
Comments: | A pyridoxal-phosphate protein. The enzyme cleaves a carbon-sulfur bond, releasing hydrogen sulfide and an unstable enamine product that tautomerizes to an imine form, which undergoes a hydrolytic deamination to form 2-oxobutanoate and ammonia. The latter reaction, which can occur spontaneously, can also be catalysed by EC 3.5.99.10, 2-iminobutanoate/2-iminopropanoate deaminase | ||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9024-41-3 | ||
References: |
| ||