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.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 15238910     2 TKWMFFFDVDEFLhVPVKE--TISSVMESLEEYFQFTIELmPMSSRVCYSGDGPARTYRKWGIEKLAYRDVkkvpRRDRK 79
Cdd:pfam01697  99 AKWIAFVDLDERL-VPTKSptTLEEFLREFADEPVISLQF-RNRWVLKYNSIPAKYFSLKQLIGNMIFLKY----RETGK 172

                          90       100
                  ....*....|....*....|..
gi 15238910    80 YAVQPENVFAIGVHMSQNLQGK 101
Cdd:pfam01697 173 CIVRPEKVNSTWIHFPRKFYPG 194

Glycosyltransferase family 92; Members of this family act as galactosyltransferases, belonging to glycosyltransferase family 92. The aligned region contains several conserved cysteine residues and several charged residues that may be catalytic residues. This is supported by the inclusion of this family in the GT-A glycosyl transferase superfamily.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 15238910     2 TKWMFFFDVDEFLhVPVKE--TISSVMESLEEYFQFTIELmPMSSRVCYSGDGPARTYRKWGIEKLAYRDVkkvpRRDRK 79
Cdd:pfam01697  99 AKWIAFVDLDERL-VPTKSptTLEEFLREFADEPVISLQF-RNRWVLKYNSIPAKYFSLKQLIGNMIFLKY----RETGK 172

                          90       100
                  ....*....|....*....|..
gi 15238910    80 YAVQPENVFAIGVHMSQNLQGK 101
Cdd:pfam01697 173 CIVRPEKVNSTWIHFPRKFYPG 194

Glycosyltransferase family 92; Members of this family act as galactosyltransferases, belonging to glycosyltransferase family 92. The aligned region contains several conserved cysteine residues and several charged residues that may be catalytic residues. This is supported by the inclusion of this family in the GT-A glycosyl transferase superfamily.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 15238910     2 TKWMFFFDVDEFLhVPVKE--TISSVMESLEEYFQFTIELmPMSSRVCYSGDGPARTYRKWGIEKLAYRDVkkvpRRDRK 79
Cdd:pfam01697  99 AKWIAFVDLDERL-VPTKSptTLEEFLREFADEPVISLQF-RNRWVLKYNSIPAKYFSLKQLIGNMIFLKY----RETGK 172

                          90       100
                  ....*....|....*....|..
gi 15238910    80 YAVQPENVFAIGVHMSQNLQGK 101
Cdd:pfam01697 173 CIVRPEKVNSTWIHFPRKFYPG 194