Adenosylhomocysteinase
Adenosylhomocysteinase (EC 3.3.1.1, S-adenosylhomocysteine synthase, S-adenosylhomocysteine hydrolase, adenosylhomocysteine hydrolase, S-adenosylhomocysteinase, SAHase, AdoHcyase) is an enzyme that converts S-adenosylhomocysteine to homocysteine and adenosine.[1][2] This enzyme catalyses the following chemical reaction
- S-adenosyl-L-homocysteine + H2O ⇌ L-homocysteine + adenosine
| S-Adenosylhomocysteine hydrolase | |||||||
|---|---|---|---|---|---|---|---|
 SAH hydrolase tetramer, Human | |||||||
| Identifiers | |||||||
| Symbol | AHCY | ||||||
| NCBI gene | 191 | ||||||
| HGNC | 343 | ||||||
| OMIM | 180960 | ||||||
| RefSeq | NM_000687 | ||||||
| UniProt | P23526 | ||||||
| Other data | |||||||
| EC number | 3.3.1.1 | ||||||
| Locus | Chr. 20 q11.22 | ||||||
| |||||||
The enzyme contains one tightly bound NAD+ per subunit. The mechanism involves dehydrogenative oxidation of the 3'-OH of the ribose. The resulting ketone is susceptible to α-deprotonation. The resulting carbanion eliminates thiolate. The a,b-unsaturated ketone is then hydrated, and the ketone is reduced by the NADH.
References
- De La Haba G, Cantoni GL (March 1959). "The enzymatic synthesis of S-adenosyl-L-homocysteine from adenosine and homocysteine". The Journal of Biological Chemistry. 234 (3): 603–8. PMID 13641268.
- Palmer JL, Abeles RH (February 1979). "The mechanism of action of S-adenosylhomocysteinase". The Journal of Biological Chemistry. 254 (4): 1217–26. PMID 762125.
External links
- Adenosylhomocysteinase at the US National Library of Medicine Medical Subject Headings (MeSH)
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.