Phosphoribosyltransferases (PRT) are enzymes that catalyze the synthesis of
β-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 22.214.171.124) (APRT), which is involved in
Hypoxanthine-guanine or hypoxanthine phosphoribosyltransferase (EC 126.96.36.199)
(HGPRT or HPRT), which are involved in purine salvage.
Orotate phosphoribosyltransferase (EC 188.8.131.52) (OPRT), which is involved
in pyrimidine biosynthesis.
Amido phosphoribosyltransferase (EC 184.108.40.206), which is involved in purine
Xanthine-guanine phosphoribosyltransferase (EC 220.127.116.11) (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
In position 11 of the pattern most of these enzymes have Gly.
November 1997 / Pattern and text revised.
PROSITE method (with tools and information) covered by this documentation:
Hershey H.V., Taylor M.W.
Nucleotide sequence and deduced amino acid sequence of Escherichia coli adenine phosphoribosyltransferase and comparison with other analogous enzymes.
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