Uridine phosphorylase

In enzymology, an uridine phosphorylase (EC 2.4.2.3) is an enzyme that catalyzes the chemical reaction

uridine + phosphate uracil + alpha-D-ribose 1-phosphate

Thus, the two substrates of this enzyme are uridine and phosphate, whereas its two products are uracil and alpha-D-ribose 1-phosphate.

This enzyme belongs to the family of glycosyltransferases, specifically the pentosyltransferases. The systematic name of this enzyme class is uridine:phosphate alpha-D-ribosyltransferase. Other names in common use include pyrimidine phosphorylase, UrdPase, UPH, and UPase. This enzyme participates in pyrimidine metabolism.

Structural studies

As of late 2007, 27 structures have been solved for this class of enzymes, with PDB accession codes 1K3F, 1LX7, 1RXC, 1RXS, 1RXU, 1RXY, 1RYZ, 1SJ9, 1SQ6, 1T0U, 1TGV, 1TGY, 1U1C, 1U1D, 1U1E, 1U1F, 1U1G, 1Y1Q, 1Y1R, 1Y1S, 1Y1T, 1ZL2, 2HN9, 2HRD, 2HSW, 2HWU, and 2I8A.

References

• CANELLAKIS ES (1957). "Pyrimidine metabolism. II. Enzymatic pathways of uracil anabolism". J. Biol. Chem. 227 (1): 329–38. PMID 13449076. 
• PAEGE LM, SCHLENK F (1952). "Bacterial uracil riboside phosphorylase". Arch. Biochem. Biophys. 40 (1): 42–9. doi:10.1016/0003-9861(52)90071-4. PMID 12997187. 
• Pontis H, Degerstedt G and Reichard P (1961). "Uridine and deoxyuridine phosphorylases from Ehrlich ascites tumor". Biochim. Biophys. Acta 51 (1): 138–147. doi:10.1016/0006-3002(61)91024-1. PMID 13737038.