This web page was produced as an assignment for Genetics 564, an undergraduate capstone course at UW-Madison.
Galactose-1-phosphate uridylyltransferase: GALT
GALT encodes a galactose-1-phosphate uridylyltransferase, which catalyzes the second step in the Leloir pathway, converting UDP-glucose and galactose-1-phosphate to glucose-1-phosphate and UDP-galactose (Fig. 5). This happens via a ping-pong bi bi kinetics with a double displacement mechanism (A-B + C-D → A-D + C-B) . This means that the GALT enzyme reacts with UDP-glucose first to create glucose 1-phosphate and GALT-UMP. Next the GALT-UMP reacts with galactose-1-phosphate to create UDP-galactose and a GALT. This metabolic function is conserved across a wide swath of life, from Humans to the single-celled bacterium Escherichia coli. See more about the metabolic processes GALT is invloved with in the Gene Ontology page.