It is named after Luis Federico Leloir, who first described it.
[1][2][3][4] In the first step, galactose mutarotase facilitates the conversion of β-D-galactose to α-D-galactose since this is the active form in the pathway.
Next, α-D-galactose is phosphorylated by galactokinase to galactose 1-phosphate.
In the third step, D-galactose-1-phosphate uridylyltransferase converts galactose 1-phosphate to UDP-galactose using UDP-glucose as the uridine diphosphate source.
Finally, UDP-galactose 4-epimerase recycles the UDP-galactose to UDP-glucose for the transferase reaction.