UDP-glucose:hexose-1-phosphate uridylyltransferase
Galactose-1-phosphate uridylyltransferase homodimer, Human
Identifiers
EC no.	2.7.7.12
CAS no.	9026-21-5
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

In enzymology, an UDP-glucose—hexose-1-phosphate uridylyltransferase (EC 2.7.7.12) is an enzyme that catalyzes the chemical reaction

UDP-glucose + alpha-D-galactose 1-phosphate ${\displaystyle \rightleftharpoons }$ alpha-D-glucose 1-phosphate + UDP-galactose

Thus, the two substrates of this enzyme are UDP-glucose and alpha-D-galactose 1-phosphate, whereas its two products are alpha-D-glucose 1-phosphate and UDP-galactose.

This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing nucleotide groups (nucleotidyltransferases). The systematic name of this enzyme class is UDP-glucose:alpha-D-galactose-1-phosphate uridylyltransferase. Other names in common use include uridyl transferase, hexose-1-phosphate uridylyltransferase, uridyltransferase, and hexose 1-phosphate uridyltransferase. This enzyme participates in galactose metabolism and nucleotide sugars metabolism.

As of late 2007, 4 structures have been solved for this class of enzymes, with PDB accession codes 1HXQ, 2H39, 2Q4H, and 2Q4L.

• KALCKAR HM, BRAGANCA B, MUNCH-PETERSEN HM (1953). "Uridyl transferases and the formation of uridine diphosphogalactose". Nature. 172 (4388): 1038. doi:10.1038/1721038a0. PMID 13111247. S2CID 4273742.
• KURAHASHI K, SUGIMURA A (1960). "Purification and properties of galactose 1-phosphate uridyl transferase from Escherichia coli". J. Biol. Chem. 235 (4): 940–6. doi:10.1016/S0021-9258(18)69456-6. PMID 14412847.
• Mayes JS; Hansen RG (1966). "Galactose 1-phosphate uridyl transferase". Carbohydrate Metabolism. Methods Enzymol. Vol. 9. pp. 708–713. doi:10.1016/0076-6879(66)09143-2. ISBN 978-0-12-181809-8.
• Saito S, Ozutsumi M, Kurahashi K (1967). "Galactose 1-phosphate uridylyltransferase of Escherichia coli. II Further purification and characterization". J. Biol. Chem. 242 (10): 2362–8. doi:10.1016/S0021-9258(18)95970-3. PMID 5338129.
• SMITH EE, MILLS GT (1955). "The uridyl transferase of mammary gland". Biochim. Biophys. Acta. 18 (1): 152. doi:10.1016/0006-3002(55)90029-9. PMID 13260264.