| purine phosphoribosyltransferase | <enzyme> Specific purine phosphoribosyltransferases are EC 2.4.2.7 and 2.4.2.8. Registry number: EC 2.4.2.- (26 Jun 1999) |
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| purine | <biochemistry, molecular biology> A heterocyclic compound with a fused pyrimidine/imidazole ring. Planar and aromatic in character. The parent compound for the purine bases of nucleic acids. (18 Nov 1997) |
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| purine 5'-nucleotidase | <enzyme> Associated with some immunologic deficiency diseases Registry number: EC 3.1.3.- (26 Jun 1999) |
| purine base | A purine. (05 Mar 2000) |
| purine-free diet | A diet containing a minimal quantity of purine bases (meats); liver, kidney, and sweetbread especially are excluded and replaced by dairy products, fruits, and cereals; alcoholic beverages also are excluded. Synonym: purine-free diet. (05 Mar 2000) |
| purine imidazole-ring cyclase | <enzyme> Recyclises ring-opened purine formamidopyrimidines in irradiated DNA, restoring the c-8 to n-9 band, does not require ATP Registry number: EC 6.3.3.- Synonym: purir cyclase (26 Jun 1999) |
| purine-nucleoside phosphorylase | <enzyme> An enzyme that catalyses the reaction between a purine nucleoside and orthophosphate to form a free purine plus ribose-5-phosphate. Chemical name: Purine-nucleoside:orthophosphate ribosyltransferase Registry number: EC 2.4.2.1 (12 Dec 1998) |
| purine permease | <chemical> Enzyme in transport system of purines in yeast pichia guillermondii Chemical name: permease, purine (26 Jun 1999) |
| purine-restricted diet | See: gout diet. (05 Mar 2000) |
| purine ribonucleoside | A toxic nucleoside isolated from the mushroom Agaricus nebularis and from Streptomyces sp. Synonym: 9-beta-ribofuranosylpurine, purine ribonucleoside, ribosylpurine. (05 Mar 2000) |
| low purine diet | A diet low in precursors of purines (such as tissues rich in cells with abundant nuclei, as in liver, glandular meats, etc.) to minimise formation of uric acid. Useful in treatment of patients with gout or urate-containing renal calculi. (05 Mar 2000) |
| adenine phosphoribosyltransferase | <enzyme> An enzyme catalyzing the formation of AMP from adenine and phosphoribosylpyrophosphate. It can act as a salvage enzyme for recycling of adenine into nucleic acids. Chemical name: AMP:pyrophosphate phospho-D-ribosyltransferase Registry number: EC 2.4.2.7 (12 Dec 1998) |
| aminoglycoside phosphoribosyltransferase | <enzyme> Coded by neo-gene; involved in kanamycin resistance; no other information given on reaction 8/93 Registry number: EC 2.4.2.- Synonym: aminoglycosidephosphoribosyltransferase (26 Jun 1999) |
| anthranilate phosphoribosyltransferase | <enzyme> An enzyme that catalyses the formation of n-5'-phosphoribosylanthranilic acid from anthranilate and phosphoribosylpyrophosphate, the first step in tryptophan synthesis in e. Coli. It exists in a complex with anthranilate synthase in bacteria. Chemical name: N-(5-Phospho-D-ribosyl)-anthranilate:pyrophosphate phospho-alpha-D-ribosyltransferase Registry number: EC 2.4.2.18 (12 Dec 1998) |
| ATP phosphoribosyltransferase | <enzyme> An enzyme that catalyses the first step of the pathway for histidine biosynthesis in salmonella typhimurium. ATP reacts reversibly with 5-phosphoribosyl-1-pyrophosphate to yield n-1-(5'-phosphoribosyl)-ATP and pyrophosphate. Chemical name: 1-(5-Phospho-D-ribosyl)-ATP:pyrophosphate phospho-alpha-D- ribosyltransferase Registry number: EC 2.4.2.17 (12 Dec 1998) |
| phosphoribosyltransferase | One of a group of enzymes (EC sub-subclass 2.4.2, pentosyltransferases) that transfers d-ribose 5-phosphate from 5-phospho-alpha-d-ribosyl pyrophosphate to a purine, pyrimidine, or pyridine acceptor, forming a 5'-nucleotide and inorganic pyrophosphate, or d-ribose from d-ribosyl phosphate to a base, forming a nucleoside, or similar pentose transfers; important in nucleotide biosynthesis. Specific phosphoribosyltransferases are preceded by the name of the acceptor base, e.g., uracil phosphoribosyltransferase (i.e., uracil + PRPP &dblarr; UMP + pyrophosphate). (05 Mar 2000) |