Enzymes
| UniProtKB help_outline | 4 proteins |
| Enzyme class help_outline |
|
| GO Molecular Function help_outline |
|
Reaction participants Show >> << Hide
- Name help_outline an α-L-fucosyl-(1→2)-β-D-galactosyl derivative Identifier CHEBI:140327 Charge 0 Formula C12H21O10R SMILEShelp_outline [C@@H]1([C@@H](O[C@@H]([C@@H]([C@@H]1O)O)CO)O*)O[C@H]2[C@H]([C@@H]([C@@H]([C@@H](O2)C)O)O)O 2D coordinates Mol file for the small molecule Search links Involved in 4 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline UDP-N-acetyl-α-D-galactosamine Identifier CHEBI:67138 Charge -2 Formula C17H25N3O17P2 InChIKeyhelp_outline LFTYTUAZOPRMMI-NESSUJCYSA-L SMILEShelp_outline CC(=O)N[C@@H]1[C@@H](O)[C@@H](O)[C@@H](CO)O[C@@H]1OP([O-])(=O)OP([O-])(=O)OC[C@H]1O[C@H]([C@H](O)[C@@H]1O)n1ccc(=O)[nH]c1=O 2D coordinates Mol file for the small molecule Search links Involved in 38 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline an N-acetyl-α-D-galactosaminyl-(1→3)-[α-L-fucosyl-(1→2)]-β-D-galactosyl derivative Identifier CHEBI:140559 Charge 0 Formula C20H34NO15R SMILEShelp_outline [C@@H]1([C@@H](O[C@@H]([C@@H]([C@@H]1O[C@@H]2[C@@H]([C@H]([C@H]([C@H](O2)CO)O)O)NC(C)=O)O)CO)O*)O[C@H]3[C@H]([C@@H]([C@@H]([C@@H](O3)C)O)O)O 2D coordinates Mol file for the small molecule Search links Involved in 3 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H+ Identifier CHEBI:15378 Charge 1 Formula H InChIKeyhelp_outline GPRLSGONYQIRFK-UHFFFAOYSA-N SMILEShelp_outline [H+] 2D coordinates Mol file for the small molecule Search links Involved in 9,176 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline UDP Identifier CHEBI:58223 Charge -3 Formula C9H11N2O12P2 InChIKeyhelp_outline XCCTYIAWTASOJW-XVFCMESISA-K SMILEShelp_outline O[C@@H]1[C@@H](COP([O-])(=O)OP([O-])([O-])=O)O[C@H]([C@@H]1O)n1ccc(=O)[nH]c1=O 2D coordinates Mol file for the small molecule Search links Involved in 542 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:19021 | RHEA:19022 | RHEA:19023 | RHEA:19024 | |
|---|---|---|---|---|
| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
| UniProtKB help_outline |
|
|||
| EC numbers help_outline | ||||
| Gene Ontology help_outline | ||||
| KEGG help_outline | ||||
| MetaCyc help_outline |
Publications
-
Structural effects of naturally occurring human blood group B galactosyltransferase mutations adjacent to the DXD motif.
Persson M., Letts J.A., Hosseini-Maaf B., Borisova S.N., Palcic M.M., Evans S.V., Olsson M.L.
Human blood group A and B antigens are produced by two closely related glycosyltransferase enzymes. An N-acetylgalactosaminyltransferase (GTA) utilizes UDP-GalNAc to extend H antigen acceptors (Fuc alpha(1-2)Gal beta-OR) producing A antigens, whereas a galactosyltransferase (GTB) utilizes UDP-Gal ... >> More
Human blood group A and B antigens are produced by two closely related glycosyltransferase enzymes. An N-acetylgalactosaminyltransferase (GTA) utilizes UDP-GalNAc to extend H antigen acceptors (Fuc alpha(1-2)Gal beta-OR) producing A antigens, whereas a galactosyltransferase (GTB) utilizes UDP-Gal as a donor to extend H structures producing B antigens. GTA and GTB have a characteristic (211)DVD(213) motif that coordinates to a Mn(2+) ion shown to be critical in donor binding and catalysis. Three GTB mutants, M214V, M214T, and M214R, with alterations adjacent to the (211)DVD(213) motif have been identified in blood banking laboratories. From serological phenotyping, individuals with the M214R mutation show the B(el) variant expressing very low levels of B antigens, whereas those with M214T and M214V mutations give rise to A(weak)B phenotypes. Kinetic analysis of recombinant mutant GTB enzymes revealed that M214R has a 1200-fold decrease in k(cat) compared with wild type GTB. The crystal structure of M214R showed that DVD motif coordination to Mn(2+) was disrupted by Arg-214 causing displacement of the metal by a water molecule. Kinetic characterizations of the M214T and M214V mutants revealed they both had GTA and GTB activity consistent with the serology. The crystal structure of the M214T mutant showed no change in DVD coordination to Mn(2+). Instead a critical residue, Met-266, which is responsible for determining donor specificity, had adopted alternate conformations. The conformation with the highest occupancy opens up the active site to accommodate the larger A-specific donor, UDP-GalNAc, accounting for the dual specificity. << Less
-
The structural basis for specificity in human ABO(H) blood group biosynthesis.
Patenaude S.I., Seto N.O.L., Borisova S.N., Szpacenko A., Marcus S.L., Palcic M.M., Evans S.V.
The human ABO(H) blood group antigens are produced by specific glycosyltransferase enzymes. An N-acetylgalactosaminyltransferase (GTA) uses a UDP-GalNAc donor to convert the H-antigen acceptor to the A antigen, whereas a galactosyltransferase (GTB) uses a UDP-galactose donor to convert the H-antig ... >> More
The human ABO(H) blood group antigens are produced by specific glycosyltransferase enzymes. An N-acetylgalactosaminyltransferase (GTA) uses a UDP-GalNAc donor to convert the H-antigen acceptor to the A antigen, whereas a galactosyltransferase (GTB) uses a UDP-galactose donor to convert the H-antigen acceptor to the B antigen. GTA and GTB differ only in the identity of four critical amino acid residues. Crystal structures at 1.8-1.32 A resolution of the GTA and GTB enzymes both free and in complex with disaccharide H-antigen acceptor and UDP reveal the basis for donor and acceptor specificity and show that only two of the critical amino acid residues are positioned to contact donor or acceptor substrates. Given the need for stringent stereo- and regioselectivity in this biosynthesis, these structures further demonstrate that the ability of the two enzymes to distinguish between the A and B donors is largely determined by a single amino acid residue. << Less
-
Complete purification and characterization of alpha-3-N-acetylgalactosaminyltransferase encoded by the human blood group A gene.
Takeya A., Hosomi O., Ishiura M.
Human alpha-3-N-acetylgalactosaminyltransferase has been purified 27,000,000-fold from A1 plasma by (NH4)2SO4 fractionation and affinity chromatography on Sepharose 4B, anti-human group O plasma antibodies-Sepharose 4B, and Blue Dextran-Sephadex G-25. A modified procedure in the Sepharose 4B step ... >> More
Human alpha-3-N-acetylgalactosaminyltransferase has been purified 27,000,000-fold from A1 plasma by (NH4)2SO4 fractionation and affinity chromatography on Sepharose 4B, anti-human group O plasma antibodies-Sepharose 4B, and Blue Dextran-Sephadex G-25. A modified procedure in the Sepharose 4B step was developed by batch adsorption and desorption experiments. Cibacron Blue F3G-A, the chromophore of Blue Dextran, was found to bind to the enzyme. UDP is an effective inhibitor of this binding. The pure transferase has an apparent molecular weight of 35,000 as judged by SDS-PAGE in the presence of a reducing agent. The specific activity is 16 pmol/min.ng enzyme, which is comparable to that (30 pmol/min.ng enzyme) of alpha-3-N-acetylgalactosaminyltransferase from porcine submaxillary glands [Schwyzer and Hill (1977) J. Biol. Chem. 252, 2338-2355]. The apparent Km values for UDP-GalNAc, 2'-fucosyllactose, and lacto-N-fucopentaose I are 13, 270, and 350 microM, respectively. The reaction velocity was found to fall off again at high concentrations of oligosaccharide acceptor substrates. The apparent Ki values for UDP and UDP-galactose are 8.6 and 6.2 microM, respectively. The pure enzyme also catalyzes the transfer of galactose in alpha-linkage to 2'-fucosyllactose though the transfer rate of galactose is much lower than that of N-acetylgalactosamine. << Less
-
Characterisation of a blood-group A-active tetrasaccharide synthesised by a blood-group B gene-specified glycosyltransferase.
Yates A.D., Feeney J., Donald A.S., Watkins W.M.
The B gene-specified alpha-D-(1----3)-galactosyltransferase, isolated from the serum of a blood-group B individual, was used to catalyse the transfer of N-acetyl-D-galactosamine from UDP-N-acetyl-D-galactosamine to the blood-group H-active trisaccharide 2'-fucosyllactose. The biosynthetic product ... >> More
The B gene-specified alpha-D-(1----3)-galactosyltransferase, isolated from the serum of a blood-group B individual, was used to catalyse the transfer of N-acetyl-D-galactosamine from UDP-N-acetyl-D-galactosamine to the blood-group H-active trisaccharide 2'-fucosyllactose. The biosynthetic product had blood-group A activity and its structure was confirmed as alpha-D-GalpNAc-(1----3)-[alpha-L-Fucp-(1----2)]-beta-D-Galp-(1----4)-D-Glc by methylation analysis and high-resolution 1H-n.m.r. spectroscopy. This tetrasaccharide was structurally and serologically identical with that made from the same donor and acceptor substrates when the blood-group A gene-specified alpha-D-(1----3)-N-acetylgalactosaminyltransferase was used as the enzyme source. The enzyme encoded by the B gene at the blood group ABO locus thus has overlapping donor substrate specificity with the enzyme encoded by the allelic A gene, and this property confers upon the B gene-specified alpha-D-1----3)-galactosyltransferase the potential to synthesise blood-group A-active structures. << Less