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| | ==CRYSTAL STRUCTURE OF W314A-BETA-1,4-GALACTOSYLTRANSFERASE (B4GAL-T1) CATALYTIC DOMAIN WITHOUT SUBSTRATE== | | ==CRYSTAL STRUCTURE OF W314A-BETA-1,4-GALACTOSYLTRANSFERASE (B4GAL-T1) CATALYTIC DOMAIN WITHOUT SUBSTRATE== |
| - | <StructureSection load='1pzt' size='340' side='right' caption='[[1pzt]], [[Resolution|resolution]] 1.92Å' scene=''> | + | <StructureSection load='1pzt' size='340' side='right'caption='[[1pzt]], [[Resolution|resolution]] 1.92Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[1pzt]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Bovin Bovin]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1PZT OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1PZT FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[1pzt]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Bos_taurus Bos taurus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1PZT OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1PZT FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.92Å</td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1fgx|1fgx]], [[1o0r|1o0r]]</td></tr>
| + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">B4GALT1, GGTB2 OR GALT ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9913 BOVIN])</td></tr> | + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1pzt FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1pzt OCA], [https://pdbe.org/1pzt PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1pzt RCSB], [https://www.ebi.ac.uk/pdbsum/1pzt PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1pzt ProSAT]</span></td></tr> |
| - | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/N-acetyllactosamine_synthase N-acetyllactosamine synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.4.1.90 2.4.1.90] </span></td></tr>
| + | |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1pzt FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1pzt OCA], [http://pdbe.org/1pzt PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1pzt RCSB], [http://www.ebi.ac.uk/pdbsum/1pzt PDBsum]</span></td></tr> | + | |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/B4GT1_BOVIN B4GT1_BOVIN]] The Golgi complex form catalyzes the production of lactose in the lactating mammary gland and could also be responsible for the synthesis of complex-type N-linked oligosaccharides in many glycoproteins as well as the carbohydrate moieties of glycolipids. The cell surface form functions as a recognition molecule during a variety of cell to cell and cell to matrix interactions, as those occurring during development and egg fertilization, by binding to specific oligosaccharide ligands on opposing cells or in the extracellular matrix. | + | [https://www.uniprot.org/uniprot/B4GT1_BOVIN B4GT1_BOVIN] The Golgi complex form catalyzes the production of lactose in the lactating mammary gland and could also be responsible for the synthesis of complex-type N-linked oligosaccharides in many glycoproteins as well as the carbohydrate moieties of glycolipids. The cell surface form functions as a recognition molecule during a variety of cell to cell and cell to matrix interactions, as those occurring during development and egg fertilization, by binding to specific oligosaccharide ligands on opposing cells or in the extracellular matrix. |
| | == Evolutionary Conservation == | | == Evolutionary Conservation == |
| | [[Image:Consurf_key_small.gif|200px|right]] | | [[Image:Consurf_key_small.gif|200px|right]] |
| | Check<jmol> | | Check<jmol> |
| | <jmolCheckbox> | | <jmolCheckbox> |
| - | <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/pz/1pzt_consurf.spt"</scriptWhenChecked> | + | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/pz/1pzt_consurf.spt"</scriptWhenChecked> |
| - | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | + | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked> |
| | <text>to colour the structure by Evolutionary Conservation</text> | | <text>to colour the structure by Evolutionary Conservation</text> |
| | </jmolCheckbox> | | </jmolCheckbox> |
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| | ==See Also== | | ==See Also== |
| - | *[[Glycosyltransferase|Glycosyltransferase]] | + | *[[Glycosyltransferase 3D structures|Glycosyltransferase 3D structures]] |
| | == References == | | == References == |
| | <references/> | | <references/> |
| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Bovin]] | + | [[Category: Bos taurus]] |
| - | [[Category: N-acetyllactosamine synthase]] | + | [[Category: Large Structures]] |
| - | [[Category: Boeggeman, E]] | + | [[Category: Boeggeman E]] |
| - | [[Category: Qasba, P K]] | + | [[Category: Qasba PK]] |
| - | [[Category: Ramakrishnan, B]] | + | [[Category: Ramakrishnan B]] |
| - | [[Category: Ramasamy, V]] | + | [[Category: Ramasamy V]] |
| - | [[Category: 4-galactosyltransferase-i tryptophan mutant]]
| + | |
| - | [[Category: Beta1]]
| + | |
| - | [[Category: Catalytic mechanism]]
| + | |
| - | [[Category: Flexible loop conformation]]
| + | |
| - | [[Category: Protease digestion]]
| + | |
| - | [[Category: Substrate binding]]
| + | |
| - | [[Category: Transferase]]
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| Structural highlights
Function
B4GT1_BOVIN The Golgi complex form catalyzes the production of lactose in the lactating mammary gland and could also be responsible for the synthesis of complex-type N-linked oligosaccharides in many glycoproteins as well as the carbohydrate moieties of glycolipids. The cell surface form functions as a recognition molecule during a variety of cell to cell and cell to matrix interactions, as those occurring during development and egg fertilization, by binding to specific oligosaccharide ligands on opposing cells or in the extracellular matrix.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
beta1,4-Galactosyltransferase-I (beta4Gal-T1) undergoes critical conformational changes upon substrate binding from an open conformation (conf-I) to the closed conformation (conf-II). This change involves two flexible loops: the small (residues 313-316) and the long loop (residues 345-365). Upon substrate binding, Trp314 in the small flexible loop moves towards the catalytic pocket and interacts with the donor and the acceptor substrates. For a better understanding of the role played by Trp314 in the conformational changes of beta4Gal-T1, we mutated it to Ala and carried out substrate-binding, proteolytic and crystallographic studies. The W314A mutation reduces the enzymatic activity, binding to substrates and to the modifier protein, alpha-lactalbumin (LA), by over 99%. The limited proteolysis with Glu-C or Lys-C proteases shows differences in the rate of cleavage of the long loop of the wild-type and mutant W314A, indicating conformational differences in the region between the two proteins. Without substrate, the mutant crystallizes in a conformation (conf-I') (1.9A resolution crystal structure), that is not identical with, but close to an open conformation (conf-I), whereas its complex with the substrates and alpha-lactalbumin, crystallizes in a conformation (2.3A resolution crystal structure) that is identical with the closed conformation (conf-II). This study shows the crucial role Trp314 plays in the conformational state of the long loop, in the binding of substrates and in the catalytic mechanism of the enzyme.
The role of tryptophan 314 in the conformational changes of beta1,4-galactosyltransferase-I.,Ramasamy V, Ramakrishnan B, Boeggeman E, Qasba PK J Mol Biol. 2003 Aug 29;331(5):1065-76. PMID:12927542[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Ramasamy V, Ramakrishnan B, Boeggeman E, Qasba PK. The role of tryptophan 314 in the conformational changes of beta1,4-galactosyltransferase-I. J Mol Biol. 2003 Aug 29;331(5):1065-76. PMID:12927542
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