Rhea - reaction knowledgebase

Enzymes

UniProtKB ^help_outline	4 proteins
Enzyme class ^help_outline	EC 2.4.1.134 galactosylxylosylprotein 3-beta-galactosyltransferase
GO Molecular Function ^help_outline	GO:0047220 galactosylxylosylprotein 3-beta-galactosyltransferase activity

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Name^help_outline 3-O-(β-D-galactosyl-(1→4)-β-D-xylosyl)-L-seryl-[protein] Identifier RHEA-COMP:12570 Reactive part ^help_outline
- Name ^help_outline O³-(4-β-D-galactosyl-β-D-xylosyl)-L-serine residue Identifier CHEBI:132088 Charge 0 Formula C14H23NO11 SMILES^help_outline O([C@H]1[C@@H]([C@H]([C@H]([C@H](O1)CO)O)O)O)[C@@H]2CO[C@H]([C@@H]([C@H]2O)O)OC[C@@H](C(*)=O)N* 2D coordinates Mol file for the small molecule Search links Involved in 2 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Search links Involved in 2 reaction(s) Find proteins in UniProtKB for this molecule
Name ^help_outline UDP-α-D-galactose Identifier CHEBI:66914 Charge -2 Formula C15H22N2O17P2 InChIKey^help_outline HSCJRCZFDFQWRP-ABVWGUQPSA-L SMILES^help_outline OC[C@H]1O[C@H](OP([O-])(=O)OP([O-])(=O)OC[C@H]2O[C@H]([C@H](O)[C@@H]2O)n2ccc(=O)[nH]c2=O)[C@H](O)[C@@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 105 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Name^help_outline 3-O-(β-D-galactosyl-(1→3)-β-D-galactosyl-(1→4)-β-D-xylosyl)-L-seryl-[protein] Identifier RHEA-COMP:12571 Reactive part ^help_outline
- Name ^help_outline O³-(β-D-galactosyl-(1→3)-β-D-galactosyl-(1→4)-β-D-xylosyl)-L-serine residue Identifier CHEBI:132090 Charge 0 Formula C20H33NO16 SMILES^help_outline O([C@H]1[C@@H]([C@H]([C@@H](CO1)O[C@H]2[C@@H]([C@H]([C@H]([C@H](O2)CO)O)O[C@H]3[C@@H]([C@H]([C@H]([C@H](O3)CO)O)O)O)O)O)O)C[C@@H](C(*)=O)N* 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
Search links Involved in 3 reaction(s) Find proteins in UniProtKB for this molecule
Name ^help_outline H⁺ Identifier CHEBI:15378 Charge 1 Formula H InChIKey^help_outline GPRLSGONYQIRFK-UHFFFAOYSA-N SMILES^help_outline [H+] 2D coordinates Mol file for the small molecule Search links Involved in 9,431 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 InChIKey^help_outline XCCTYIAWTASOJW-XVFCMESISA-K SMILES^help_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 576 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule

Cross-references

	RHEA:11780	RHEA:11781	RHEA:11782	RHEA:11783
Reaction direction	undefined	left-to-right	right-to-left	bidirectional
UniProtKB ^help_outline	4 proteins	2 proteins
EC numbers ^help_outline	2.4.1.134
Gene Ontology ^help_outline	GO:0047220
KEGG ^help_outline				R05927
MetaCyc ^help_outline		2.4.1.134-RXN

Publications

Initiation of chondroitin sulphate synthesis by beta-D-galactosides. Substrates for galactosyltransferase II.

Robinson J.A., Robinson H.C.

beta-Galactosides were found to initiate chondroitin sulphate chain synthesis in chick-embryo cartilage in vitro and thereby relieve inhibition by cycloheximide of [3H]-acetate incorporation into chondroitin sulphate. beta-Galactosides with an apolar aglycan group such as phenyl O-beta-galactoside ... >> More

beta-Galactosides were found to initiate chondroitin sulphate chain synthesis in chick-embryo cartilage in vitro and thereby relieve inhibition by cycloheximide of [3H]-acetate incorporation into chondroitin sulphate. beta-Galactosides with an apolar aglycan group such as phenyl O-beta-galactoside were active, whereas those with a charged or polar aglycan group such as pyridine 3-O-beta-galactoside or those with sulphur instead of oxygen in the glycosidic linkage (phenyl beta-thiogalactoside) were not. beta-Galactosides also serve as substrates for microsomal galactosyltransferase activity from chick-embryo cartilage. Phenyl O-beta-galactoside and pyridine 3-O-beta-galactoside were effective substrates for this enzyme, but phenyl S-beta-thiogalactoside and pyridine 2-S-beta-thiogalactoside were only slightly active. This galactosyltransferase was shown to be a separate enzyme from galactosyltransferase I, which catalyses transfer of galactose from UDP-galactose to beta-xylosides. It is proposed that the enzyme catalysing this reaction is galactosyltransferase II, responsible for transfer of the second galactose residue of the chondroitin sulphate linkage oligosaccharide. No transfer of glucuronic acid from UDP-glucuronic acid to beta-galactosides, catalysed by the microsomal preparation could be detected. << Less

Biochem J 227:805-814(1985) [PubMed] [EuropePMC]
Biosynthesis of the linkage region of glycosaminoglycans: cloning and activity of galactosyltransferase II, the sixth member of the beta 1,3-galactosyltransferase family (beta 3GalT6).

Bai X., Zhou D., Brown J.R., Crawford B.E., Hennet T., Esko J.D.

A family of five beta1,3-galactosyltransferases has been characterized that catalyze the formation of Galbeta1,3GlcNAcbeta and Galbeta1,3GalNAcbeta linkages present in glycoproteins and glycolipids (beta3GalT1, -2, -3, -4, and -5). We now report a new member of the family (beta3GalT6), involved in ... >> More

A family of five beta1,3-galactosyltransferases has been characterized that catalyze the formation of Galbeta1,3GlcNAcbeta and Galbeta1,3GalNAcbeta linkages present in glycoproteins and glycolipids (beta3GalT1, -2, -3, -4, and -5). We now report a new member of the family (beta3GalT6), involved in glycosaminoglycan biosynthesis. The human and mouse genes were located on chromosomes 1p36.3 and 4E2, respectively, and homologs are found in Drosophila melanogaster and Caenorhabditis elegans. Unlike other members of the family, beta3GalT6 showed a broad mRNA expression pattern by Northern blot analysis. Although a high degree of homology across several subdomains exists among other members of the beta3-galactosyltransferase family, recombinant enzyme did not utilize glucosamine- or galactosamine-containing acceptors. Instead, the enzyme transferred galactose from UDP-galactose to acceptors containing a terminal beta-linked galactose residue. This product, Galbeta1,3Galbeta is found in the linkage region of heparan sulfate and chondroitin sulfate (GlcAbeta1,3Galbeta1,3Galbeta1,4Xylbeta-O-Ser), indicating that beta3GalT6 is the so-called galactosyltransferase II involved in glycosaminoglycan biosynthesis. Its identity was confirmed in vivo by siRNA-mediated inhibition of glycosaminoglycan synthesis in HeLa S3 cells. Its localization in the medial Golgi indicates that this is the major site for assembly of the linkage region. << Less

J. Biol. Chem. 276:48189-48195(2001) [PubMed] [EuropePMC]
Biosynthesis of chondroitin sulfate. Solubilization of chondroitin sulfate glycosyltransferases and partial purification of uridine diphosphate-D-galactose:D-xylose galactosyltrans.

Schwartz N.B., Roden L.

UDP-D-Galactose:D-xylose galactosyltransferase, a membrane-bound enzyme which catalyzes the second glycosyl transfer reaction in the biosynthesis of chondroitin sulfate chains, has been solubilized and partially purified from embryonic chick cartilage. Solubilization was effected by treatment of a ... >> More

UDP-D-Galactose:D-xylose galactosyltransferase, a membrane-bound enzyme which catalyzes the second glycosyl transfer reaction in the biosynthesis of chondroitin sulfate chains, has been solubilized and partially purified from embryonic chick cartilage. Solubilization was effected by treatment of a particulate fraction of a homogenate (sedimenting between 10,000 and 100,000 times g) with the nonionic detergent Nonidet P-40 (0.5%) and KCl (0.5 M) or by the alkali-detergent method described previously (Helting, T. (1971) J. Biol. Chem. 246, 815-822). The applicability of the salt-detergent procedure as a general method for solubilization of membrane-bound glycosyltransferases was tested by assay of four other glycosyltransferases involved in chondroitin sulfate synthesis (UDP-D-xylose:core protein xylosyltransferase, UDP-D-galactose:4-O-beta-D-galactosyl-D-xylose galactosyltransferase, UDP-D-glucuronic acid: 3-O-beta-D-galactosyl-D-galactose glucuronosyltransferase, and UDP-N-acetyl-D-galactosamine: (GlcUA-GalNAc-4-sulfate)4 N-acetylgalactosaminyltransferase). In each case, greater than 70% of the activity was solubilized and, on gel chromatography on Sephadex G-200, the enzymes appeared largely in included positions and partially separated from each other. After partial purification by gel chromatography on Sephadex G-200, UDP-D-galactose:D-xylose galactosyltransferase was purified further by chromatography on one of several affinity matrices, i.e. xylosylated core protein of cartilage proteoglycan coupled to CNBr-activated Sepharose, a core protein matrix saturated with UDP-D-xylose:core protein xylosyltransferase or UDP-D-xylose:core protein xylosyltransferase covalently bound to Sepharose. The specific activities of the enzyme preparations obtained by these procedures were approximately 1000-fold greater than that of the crude homogenate. << Less

J Biol Chem 250:5200-5207(1975) [PubMed] [EuropePMC]

This publication is cited by 1 other entry.

RHEA:11780 3-O-(beta-D-galactosyl-(1->4)-beta-D-xylosyl)-L-seryl-[protein] + UDP-alpha-D-galactose = 3-O-(beta-D-galactosyl-(1->3)-beta-D-galactosyl-(1->4)-beta-D-xylosyl)-L-seryl-[protein] + H(+) + UDP

Enzymes

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Cross-references

Publications

Initiation of chondroitin sulphate synthesis by beta-D-galactosides. Substrates for galactosyltransferase II.

Biosynthesis of the linkage region of glycosaminoglycans: cloning and activity of galactosyltransferase II, the sixth member of the beta 1,3-galactosyltransferase family (beta 3GalT6).

Biosynthesis of chondroitin sulfate. Solubilization of chondroitin sulfate glycosyltransferases and partial purification of uridine diphosphate-D-galactose:D-xylose galactosyltrans.