1o7q: Difference between revisions

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-{{Seed}}
-[[Image:1o7q.png|left|200px]]
-<!--
+==Roles of Individual Residues of Alpha-1,3 Galactosyltransferases in Substrate Binding and Catalysis==
-The line below this paragraph, containing "STRUCTURE_1o7q", creates the "Structure Box" on the page.
+<StructureSection load='1o7q' size='340' side='right'caption='[[1o7q]], [[Resolution|resolution]] 1.30&Aring;' scene=''>
-You may change the PDB parameter (which sets the PDB file loaded into the applet)
+== Structural highlights ==
-or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
+<table><tr><td colspan='2'>[[1o7q]] is a 2 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=1O7Q OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1O7Q FirstGlance]. <br>
-or leave the SCENE parameter empty for the default display.
+</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.3&#8491;</td></tr>
--->
+<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GAL:BETA-D-GALACTOSE'>GAL</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=MN:MANGANESE+(II)+ION'>MN</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=UDP:URIDINE-5-DIPHOSPHATE'>UDP</scene></td></tr>
-{{STRUCTURE_1o7q|  PDB=1o7q  |  SCENE=  }}
+<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1o7q FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1o7q OCA], [https://pdbe.org/1o7q PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1o7q RCSB], [https://www.ebi.ac.uk/pdbsum/1o7q PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1o7q ProSAT]</span></td></tr>
+</table>
+== Function ==
+[https://www.uniprot.org/uniprot/GGTA1_BOVIN GGTA1_BOVIN] Transfer of galactose from UDP-galactose to an acceptor molecule (R).
+== Evolutionary Conservation ==
+[[Image:Consurf_key_small.gif|200px|right]]
+Check<jmol>
+  <jmolCheckbox>
+    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/o7/1o7q_consurf.spt"</scriptWhenChecked>
+    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
+    <text>to colour the structure by Evolutionary Conservation</text>
+  </jmolCheckbox>
+</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1o7q ConSurf].
+<div style="clear:both"></div>
+<div style="background-color:#fffaf0;">
+== Publication Abstract from PubMed ==
+The retaining glycosyltransferase, alpha-1,3-galactosyltransferase (alpha3GT), is mutationally inactivated in humans, leading to the presence of circulating antibodies against its product, the alpha-Gal epitope. alpha3GT catalyzes galactose transfer from UDP-Gal to beta-linked galactosides, such as lactose, and in the absence of an acceptor substrate, to water at a lower rate. We have used site-directed mutagenesis to investigate the roles in catalysis and specificity of residues in alpha3GT that form H-bonds as well as other interactions with substrates. Mutation of the conserved Glu(317) to Gln weakens lactose binding and reduces the k(cat) for galactosyltransfer to lactose and water by 2400 and 120, respectively. The structure is not perturbed by this substitution, but the orientation of the bound lactose molecule is changed. The magnitude of these changes does not support a previous proposal that Glu(317) is the catalytic nucleophile in a double displacement mechanism and suggests it acts in acceptor substrate binding and in stabilizing a cationic transition state for cleavage of the bond between UDP and C1 of the galactose. Cleavage of this bond also linked to a conformational change in the C-terminal region of alpha3GT that is coupled with UDP binding. Mutagenesis indicates that His(280), which is projected to interact with the 2-OH of the galactose moiety of UDP-Gal, is a key residue in the stringent donor substrate specificity through its role in stabilizing the bound UDP-Gal in a suitable conformation for catalysis. Mutation of Gln(247), which forms multiple interactions with acceptor substrates, to Glu reduces the catalytic rate of galactose transfer to lactose but not to water. This mutation is predicted to perturb the orientation or environment of the bound acceptor substrate. The results highlight the importance of H-bonds between enzyme and substrates in this glycosyltransferase, in arranging substrates in appropriate conformations and orientation for efficient catalysis. These factors are manifested in increases in catalytic rate rather than substrate affinity.
-===ROLES OF INDIVIDUAL RESIDUES OF ALPHA-1,3 GALACTOSYLTRANSFERASES IN SUBSTRATE BINDING AND CATALYSIS===
+Roles of individual enzyme-substrate interactions by alpha-1,3-galactosyltransferase in catalysis and specificity.,Zhang Y, Swaminathan GJ, Deshpande A, Boix E, Natesh R, Xie Z, Acharya KR, Brew K Biochemistry. 2003 Nov 25;42(46):13512-21. PMID:14621997<ref>PMID:14621997</ref>
+From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
+</div>
+<div class="pdbe-citations 1o7q" style="background-color:#fffaf0;"></div>
-<!--
+==See Also==
-The line below this paragraph, {{ABSTRACT_PUBMED_14621997}}, adds the Publication Abstract to the page
+*[[Glycosyltransferase 3D structures|Glycosyltransferase 3D structures]]
-(as it appears on PubMed at http://www.pubmed.gov), where 14621997 is the PubMed ID number.
+== References ==
--->
+<references/>
-{{ABSTRACT_PUBMED_14621997}}
+__TOC__
+</StructureSection>
-==About this Structure==
-O7Q is a 2 chains structure of sequences from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1O7Q OCA].
-==Reference==
-<ref group="xtra">PMID:14621997</ref><references group="xtra"/>
 [[Category: Bos taurus]]
-[[Category: N-acetyllactosaminide 3-alpha-galactosyltransferase]]
+[[Category: Large Structures]]
-[[Category: Acharya, K R.]]
+[[Category: Acharya KR]]
-[[Category: Brew, K.]]
+[[Category: Brew K]]
-[[Category: Deshpande, A.]]
+[[Category: Deshpande A]]
-[[Category: Natesh, R.]]
+[[Category: Natesh R]]
-[[Category: Swaminathan, G J.]]
+[[Category: Swaminathan GJ]]
-[[Category: Xie, X.]]
+[[Category: Xie Z]]
-[[Category: Zhang, Y.]]
+[[Category: Zhang Y]]
-[[Category: 3-galactosyltransferase-udp complex]]
-[[Category: Alpha-1]]
-[[Category: Glycoprotein]]
-[[Category: Glycosyltransferase]]
-[[Category: Nucleotide-binding protein]]
-[[Category: Transferase]]
-[[Category: Transmembrane]]
-[[Category: Xenotransplantation]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Feb 16 11:21:37 2009''