Pyrimidine-nucleoside phosphorylase

In enzymology, a pyrimidine-nucleoside phosphorylase (EC 2.4.2.2) is an enzyme that catalyzes the chemical reaction

a pyrimidine nucleoside + phosphate ${\displaystyle \rightleftharpoons }$ a pyrimidine base + alpha-D-ribose 1-phosphate

pyrimidine-nucleoside phosphorylase
Identifiers
EC no.	2.4.2.2
CAS no.	9055-35-0
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / QuickGO
Search PMC articles PubMed articles NCBI proteins

Thus, the two substrates of this enzyme are pyrimidine nucleoside and phosphate, whereas its two products are pyrimidine base 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 pyrimidine-nucleoside:phosphate alpha-D-ribosyltransferase. This enzyme is also called Py-NPase. This enzyme participates in pyrimidine metabolism.

Structural studies

As of late 2007, two structures have been solved for this class of enzymes, with PDB accession codes 1BRW and 2DSJ.