Lipopolysaccharide 3-alpha-galactosyltransferase

In enzymology, a lipopolysaccharide 3-alpha-galactosyltransferase is an enzyme that catalyzes the chemical reaction


 * UDP-galactose + lipopolysaccharide $$\rightleftharpoons$$ UDP + 3-alpha-D-galactosyl-[lipopolysaccharide glucose]

Thus, the two substrates of this enzyme are UDP-galactose and lipopolysaccharide, whereas its two products are UDP and 3-alpha-D-galactosyl-[lipopolysaccharide glucose].

This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP-galactose:lipopolysaccharide 3-alpha-D-galactosyltransferase. Other names in common use include UDP-galactose:lipopolysaccharide alpha,3-galactosyltransferase, UDP-galactose:polysaccharide galactosyltransferase, uridine diphosphate galactose:lipopolysaccharide, alpha-3-galactosyltransferase, uridine diphosphogalactose-lipopolysaccharide, and alpha,3-galactosyltransferase. This enzyme participates in lipopolysaccharide biosynthesis and glycan structures - biosynthesis 2.

Structural studies
As of late 2007, two structures have been solved for this class of enzymes, with PDB accession codes and.