Class of enzymes
In enzymology, a xanthine phosphoribosyltransferase (EC 2.4.2.22) is an enzyme that catalyzes the chemical reaction
XMP + diphosphate formula_1 5-phospho-alpha-D-ribose 1-diphosphate + xanthine
Thus, the two substrates of this enzyme are XMP and diphosphate, whereas its two products are 5-phospho-alpha-D-ribose 1-diphosphate and xanthine.
This enzyme belongs to the family of glycosyltransferases, specifically the pentosyltransferases. The systematic name of this enzyme class is XMP:diphosphate 5-phospho-alpha-D-ribosyltransferase. Other names in common use include Xan phosphoribosyltransferase, xanthosine 5'-phosphate pyrophosphorylase, xanthylate pyrophosphorylase, xanthylic pyrophosphorylase, XMP pyrophosphorylase, 5-phospho-alpha-D-ribose-1-diphosphate:xanthine, phospho-D-ribosyltransferase, 9-(5-phospho-beta-D-ribosyl)xanthine:diphosphate, and 5-phospho-alpha-D-ribosyltransferase. This enzyme participates in purine metabolism.
Structural studies.
As of late 2007, 6 structures have been solved for this class of enzymes, with PDB accession codes 1A95, 1A96, 1A97, 1A98, 1NUL, and 2FXV.
References.
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