Glycosyltransferase family A (GT-A) includes diverse families of glycosyl transferases with a common GT-A type structural fold. Glycosyltransferases (GTs) are enzymes that synthesize oligosaccharides, polysaccharides, and glycoconjugates by transferring the sugar moiety from an activated nucleotide-sugar donor to an acceptor molecule, which may be a growing oligosaccharide, a lipid, or a protein. Based on the stereochemistry of the donor and acceptor molecules, GTs are classified as either retaining or inverting enzymes. To date, all GT structures adopt one of two possible folds, termed GT-A fold and GT-B fold. This hierarchy includes diverse families of glycosyl transferases with a common GT-A type structural fold, which has two tightly associated beta/alpha/beta domains that tend to form a continuous central sheet of at least eight beta-strands. The majority of the proteins in this superfamily are Glycosyltransferase family 2 (GT-2) proteins. But it also includes families GT-43, GT-6, GT-8, GT13 and GT-7; which are evolutionarily related to GT-2 and share structure similarities.

Glycosyltransferase family 43.

transferase, transferring glycosyl groups

Beta1,3-glucuronyltransferase I (GlcAT-I) is involved in the initial steps of proteoglycan synthesis. Beta1,3-glucuronyltransferase I (GlcAT-I) domain; GlcAT-I is a Key enzyme involved in the initial steps of proteoglycan synthesis. GlcAT-I catalyzes the transfer of a glucuronic acid moiety from the uridine diphosphate-glucuronic acid (UDP-GlcUA) to the common linkage region of trisaccharide Gal-beta-(1-3)-Gal-beta-(1-4)-Xyl of proteoglycans. The enzyme has two subdomains that bind the donor and acceptor substrate separately. The active site is located at the cleft between both subdomains in which the trisaccharide molecule is oriented perpendicular to the UDP. This family has been classified as Glycosyltransferase family 43 (GT-43).