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- ***********************************************************
- * Purine/pyrimidine phosphoribosyl transferases signature *
- ***********************************************************
-
- Phosphoribosyltransferases (PRT) are enzymes that catalyze the synthesis of
- beta-n-5'-monophosphates from phosphoribosylpyrophosphate (PRPP) and an enzyme
- specific amine. A number of PRT's are involved in the biosynthesis of purine,
- pyrimidine, and pyridine nucleotides, or in the salvage of purines and
- pyrimidines. These enzymes are:
-
- - Adenine phosphoribosyltransferase (EC 2.4.2.7) (APRT), which is involved in
- purine salvage.
- - Hypoxanthine-guanine or hypoxanthine phosphoribosyltransferase (EC 2.4.2.8)
- (HGPRT or HPRT), which are involved in purine salvage.
- - Orotate phosphoribosyltransferase (EC 2.4.2.10) (OPRT), which is involved
- in pyrimidine biosynthesis.
- - Amido phosphoribosyltransferase (EC 2.4.2.14), which is involved in purine
- biosynthesis.
- - Xanthine-guanine phosphoribosyltransferase (EC 2.4.2.22) (XGPRT), which is
- involved in purine salvage.
-
- In the sequence of all these enzymes there is a small conserved region which
- may be involved in the enzymatic activity and/or be part of the PRPP binding
- site [1].
-
- -Consensus pattern: [LIVMFYWCTA]-[LIVM](3)-[DE]-D-[LIVMS]-[LIVM]-[STAVD]-
- [STAR]-[GAC]-x-[STAR]
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: bacterial phosphoribosyl pyro-
- phosphate synthetases.
-
- -Note: in position 11 of the pattern most of these enzymes have Gly.
-
- -Last update: June 1994 / Pattern and text revised.
-
- [ 1] Hershey H.V., Taylor M.W.
- Gene 43:287-293(1986).
-