IMP cyclohydrolase activity
Definition
Target type: molecularfunction
Catalysis of the reaction: IMP + H2O = 5-formamido-1-(5-phosphoribosyl)imidazole-4-carboxamide. [EC:3.5.4.10]
IMP cyclohydrolase activity is a key enzymatic reaction in the purine nucleotide biosynthesis pathway. It catalyzes the conversion of inosine monophosphate (IMP) to 5-amino-4-imidazolecarboxamide ribonucleotide (AICAR). This conversion is essential for the synthesis of both adenine and guanine nucleotides. IMP cyclohydrolase utilizes a single molecule of water to hydrolyze the carbon-nitrogen bond at the 6 position of the purine ring in IMP. This hydrolysis reaction requires a divalent metal cation such as magnesium or manganese for optimal activity. The enzyme first binds to IMP, forming a stable enzyme-substrate complex. This complex then undergoes a conformational change that positions the water molecule for attack on the carbon-nitrogen bond. This attack results in the cleavage of the bond and the release of AICAR. The AICAR molecule then serves as a precursor for the synthesis of both AMP and GMP. Therefore, IMP cyclohydrolase plays a critical role in maintaining cellular purine nucleotide pools, which are essential for various cellular processes including DNA replication, RNA transcription, and protein synthesis.'
"
Proteins (1)
| Protein | Definition | Taxonomy |
|---|---|---|
| Bifunctional purine biosynthesis protein ATIC | A bifunctional purine biosynthesis protein ATIC that is encoded in the genome of human. [PRO:DNx, UniProtKB:P31939] | Homo sapiens (human) |
Compounds (9)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| sulfasalazine | sulfasalazine : An azobenzene consisting of diphenyldiazene having a carboxy substituent at the 4-position, a hydroxy substituent at the 3-position and a 2-pyridylaminosulphonyl substituent at the 4'-position. Sulfasalazine: A drug that is used in the management of inflammatory bowel diseases. Its activity is generally considered to lie in its metabolic breakdown product, 5-aminosalicylic acid (see MESALAMINE) released in the colon. (From Martindale, The Extra Pharmacopoeia, 30th ed, p907) | ||
| veratridine | steroid | sodium channel modulator | |
| aica ribonucleotide | AICA ribonucleotide : A 1-(phosphoribosyl)imidazolecarboxamide that is acadesine in which the hydroxy group at the 5' position has been converted to its monophosphate derivative. AICA ribonucleotide: purine precursor that has antineoplastic activity | 1-(phosphoribosyl)imidazolecarboxamide; aminoimidazole | cardiovascular drug; Escherichia coli metabolite; human metabolite; mouse metabolite; plant metabolite; Saccharomyces cerevisiae metabolite |
| methotrexate | dicarboxylic acid; monocarboxylic acid amide; pteridines | abortifacient; antimetabolite; antineoplastic agent; antirheumatic drug; dermatologic drug; DNA synthesis inhibitor; EC 1.5.1.3 (dihydrofolate reductase) inhibitor; immunosuppressive agent | |
| 5-formamidoimidazole-4-carboxamide ribotide | 5-formamidoimidazole-4-carboxamide ribotide: purine precursor | 1-(phosphoribosyl)imidazolecarboxamide | Escherichia coli metabolite; mouse metabolite |
| nsc 88915 | 4-pregnen-21-ol-3,20-dione-21-(4-bromobenzenesufonate): a tyrosyl-DNA phosphodiesterase inhibitor; structure in first source | ||
| 5,11-methenyltetrahydrohomofolate | |||
| pemetrexed | pemetrexed disodium : An organic sodium salt that is the disodium salt of N-{4-[2-(2-amino-4-oxo-4,7-dihydro-1H-pyrrolo[2,3-d]pyrimidin-5-yl)ethyl]benzoyl}-L-glutamic acid. Inhibits thymidylate synthase (TS), 421 dihydrofolate reductase (DHFR), and glycinamide ribonucleotide formyltransferase (GARFT). | N-acyl-L-glutamic acid; pyrrolopyrimidine | antimetabolite; antineoplastic agent; EC 1.5.1.3 (dihydrofolate reductase) inhibitor; EC 2.1.1.45 (thymidylate synthase) inhibitor; EC 2.1.2.2 (phosphoribosylglycinamide formyltransferase) inhibitor |
| lometrexol | lometrexol: RN & structure given in first source; |