galactose-1-phosphate uridyltransferase (gal-1-P uridyltransferase, UDP-glucose-hexose-1-phosphate uridyltransferase, GALT)

Function

• galactose metabolism, 2nd step

UDP-glucose + alpha-D-galactose 1-phosphate
                  <-->
alpha-D-glucose 1-phosphate + UDP-galactose

Cofactor:

• binds 1Fe+2/Fe+3 per subunit (putative)
• binds 1 Zn+2 ion per subunit (putative)

Structure

• homodimer
• belongs to the galactose-1-phosphate uridylyltransferase type 1 family

Pathology

• defects in GALT are the cause of galactosemia
• most common defective enzyme in galactosemia

Laboratory

• GALT gene mutation
• galactose-1-phosphate uridyl transferase in blood
  • galactose-1-phosphate uridyl transferase phenotype in blood
  • galactose-1-phosphate uridyl transferase in dried blood spot
• galactose-1-phosphate uridyl transferase in erythrocytes
• galactose-1-phosphate uridyl transferase in leukocytes

Notes

• screening programs for galactosemia based upon assay for GALT

More general terms

• nucleotidyltransferase

Database

• OMIM: https://mirror.omim.org/entry/230400
• OMIM: https://mirror.omim.org/entry/606999
• UniProt: http://www.uniprot.org/uniprot/P07902.html