Target type: molecularfunction
Catalysis of the reaction: S-adenosyl-L-homocysteine + H2O = adenosine + L-homocysteine. [RHEA:21708]
Adenosylhomocysteinase (AHCY) activity is a critical enzyme involved in the regulation of cellular metabolism, particularly the transsulfuration pathway. This pathway utilizes homocysteine, a sulfur-containing amino acid, to produce cysteine, which is an essential amino acid and precursor to glutathione. AHCY specifically catalyzes the hydrolysis of S-adenosylhomocysteine (SAH) into adenosine and homocysteine. SAH is a potent inhibitor of various methyltransferases, which are crucial for a wide range of cellular processes, including DNA replication and repair, protein synthesis, and signal transduction. By hydrolyzing SAH, AHCY removes this potent inhibitor, thereby promoting the activity of methyltransferases and ensuring the proper function of these essential enzymes. This intricate process directly influences the balance of methylation reactions, which are critical for normal cell growth and development. Deficiencies in AHCY activity can lead to a buildup of SAH and impaired methylation processes, ultimately contributing to various diseases, including neurodevelopmental disorders, cardiovascular disease, and cancer. The molecular function of AHCY activity is therefore essential for maintaining cellular homeostasis and preventing the development of diverse pathologies.'
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| Protein | Definition | Taxonomy |
|---|---|---|
| Adenosylhomocysteinase | An adenosylhomocysteinase that is encoded in the genome of human. [PRO:DNx, UniProtKB:P23526] | Homo sapiens (human) |
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| 3-deazaadenosine | 3-deazaadenosine: RN given refers to parent cpd. | ||
| ribavirin | Rebetron: Rebetron is tradename | 1-ribosyltriazole; aromatic amide; monocarboxylic acid amide; primary carboxamide | anticoronaviral agent; antiinfective agent; antimetabolite; antiviral agent; EC 2.7.7.49 (RNA-directed DNA polymerase) inhibitor |
| adenosine | quinquefolan B: isolated from roots of Panax quinquefolium L.; RN not in Chemline 10/87; RN from Toxlit | adenosines; purines D-ribonucleoside | analgesic; anti-arrhythmia drug; fundamental metabolite; human metabolite; vasodilator agent |
| aristeromycin | aristeromycin: RN given refers to (1R-(1alpha,2alpha,3beta,5alpha)-isomer | ||
| illimaquinone | illimaquinone: structure given in first source; isolated from the Red Sea sponge Smenospongia; inhibits the RNase H. activity of HIV-1 reverse transcriptase | monohydroxy-1,4-benzoquinones; prenylquinone | metabolite |
| 3-deazaaristeromycin | 3-deazaaristeromycin: antagonist of S-adenosylhomocysteinase | ||
| neplanocin a | neplanocin A: neplanocins are antitumor antibiotics & carbocyclic analogs of purine nucleosides from Ampullarilla regularis A11079; see also neplanocin B, neplanocin C, neplanocin D & neplanocin F; structure in first source; a potent inhibitor of S-adenosylhomocysteine hydrolase | ||
| 3-deazaneplanocin | 3-deazaneplanocin: S-adenosylhomocysteine hydrolase antagonist | ||
| 9-(2',3'-dihydroxycyclopentan-1'-yl)adenine | 9-(2',3'-dihydroxycyclopentan-1'-yl)adenine: inhibitor of S-adenosylhomocysteine hydrolase; structure given in first source | ||
| adenosine-5'-carboxylic acid | purine nucleoside | ||
| 5'-n-methylcarboxamideadenosine | 5'-N-methylcarboxamideadenosine: RN given refers to (beta-D)-isomer | ||
| 5'-noraristeromycin | 5'-noraristeromycin: structure given in first source | ||
| adenosine-5'-carboxaldehyde | 5'-dehydroadenosine : A member of the class of adenosines that is 5'-dehydro derivative of adenosine. adenosine-5'-carboxaldehyde: potent inhibitor of S-adenosyl-L-homocysteine hydrolase; structure given in first source | adenosines | |
| 9-(2',3'-dihydroxycyclopent-4'-enyl)adenine | |||
| 5'-amino-5'-deoxyadenosine | |||
| guanosine | ribonucleoside : Any nucleoside where the sugar component is D-ribose. | guanosines; purines D-ribonucleoside | fundamental metabolite |
| inosine | inosines; purines D-ribonucleoside | Escherichia coli metabolite; human metabolite; mouse metabolite; Saccharomyces cerevisiae metabolite |