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New page: left|200px<br /><applet load="1zdf" size="450" color="white" frame="true" align="right" spinBox="true" caption="1zdf, resolution 2.450Å" /> '''Ser162 mutant of gl... |
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== | ==Ser162 mutant of glycogenin complexed with UDP-glucose and manganese== | ||
Glycogenin is a glycosyltransferase that functions as the autocatalytic | <StructureSection load='1zdf' size='340' side='right'caption='[[1zdf]], [[Resolution|resolution]] 2.45Å' scene=''> | ||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1zdf]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Oryctolagus_cuniculus Oryctolagus cuniculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ZDF OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1ZDF FirstGlance]. <br> | |||
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.45Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MN:MANGANESE+(II)+ION'>MN</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>, <scene name='pdbligand=UPG:URIDINE-5-DIPHOSPHATE-GLUCOSE'>UPG</scene></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=1zdf FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1zdf OCA], [https://pdbe.org/1zdf PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1zdf RCSB], [https://www.ebi.ac.uk/pdbsum/1zdf PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1zdf ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/GLYG_RABIT GLYG_RABIT] Self-glucosylates, via an inter-subunit mechanism, to form an oligosaccharide primer that serves as substrate for glycogen synthase. | |||
== 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/zd/1zdf_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=1zdf ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Glycogenin is a glycosyltransferase that functions as the autocatalytic initiator for the synthesis of glycogen in eukaryotic organisms. Prior structural work identified the determinants responsible for the recognition and binding of UDP-glucose and the catalytic manganese ion and implicated two aspartic acid residues in the reaction mechanism for self-glucosylation. We examined the effects of substituting asparagine and serine for the aspartic acid residues at positions 159 and 162. We also examined whether the truncation of the protein at residue 270 (delta270) was compatible with its structural integrity and its functional role as the initiator for glycogen synthesis. The truncated form of the enzyme was indistinguishable from the wild-type enzyme by all measures of activity and could support glycogen accumulation in a glycogenin-deficient yeast strain. Substitution of aspartate 159 by either serine or asparagine eliminated self-glucosylation and reduced trans-glucosylation activity by at least 260-fold but only reduced UDP-glucose hydrolytic activity by 4-14-fold. Substitution of aspartate 162 by either serine or asparagine eliminated self-glucosylation activity and reduced UDP-glucose hydrolytic activity by at least 190-fold. The trans-glucosylation of maltose was reduced to undetectable levels in the asparagine 162 mutant, whereas the serine 162 enzyme showed only an 18-30-fold reduction in its ability to trans-glucosylate maltose. These data support a role for aspartate 162 in the chemical step for the glucosyltransferase reaction and a role for aspartate 159 in binding and activating the acceptor molecule. | |||
Requirements for catalysis in mammalian glycogenin.,Hurley TD, Stout S, Miner E, Zhou J, Roach PJ J Biol Chem. 2005 Jun 24;280(25):23892-9. Epub 2005 Apr 22. PMID:15849187<ref>PMID:15849187</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
[[Category: | <div class="pdbe-citations 1zdf" style="background-color:#fffaf0;"></div> | ||
==See Also== | |||
*[[Glycogenin|Glycogenin]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Large Structures]] | |||
[[Category: Oryctolagus cuniculus]] | [[Category: Oryctolagus cuniculus]] | ||
[[Category: Hurley TD]] | |||
[[Category: Hurley | [[Category: Miner E]] | ||
[[Category: Miner | [[Category: Roach PJ]] | ||
[[Category: Roach | [[Category: Stout SL]] | ||
[[Category: Stout | [[Category: Zhou J]] | ||
[[Category: Zhou | |||
Latest revision as of 10:07, 23 August 2023
Ser162 mutant of glycogenin complexed with UDP-glucose and manganeseSer162 mutant of glycogenin complexed with UDP-glucose and manganese
Structural highlights
FunctionGLYG_RABIT Self-glucosylates, via an inter-subunit mechanism, to form an oligosaccharide primer that serves as substrate for glycogen synthase. 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 PubMedGlycogenin is a glycosyltransferase that functions as the autocatalytic initiator for the synthesis of glycogen in eukaryotic organisms. Prior structural work identified the determinants responsible for the recognition and binding of UDP-glucose and the catalytic manganese ion and implicated two aspartic acid residues in the reaction mechanism for self-glucosylation. We examined the effects of substituting asparagine and serine for the aspartic acid residues at positions 159 and 162. We also examined whether the truncation of the protein at residue 270 (delta270) was compatible with its structural integrity and its functional role as the initiator for glycogen synthesis. The truncated form of the enzyme was indistinguishable from the wild-type enzyme by all measures of activity and could support glycogen accumulation in a glycogenin-deficient yeast strain. Substitution of aspartate 159 by either serine or asparagine eliminated self-glucosylation and reduced trans-glucosylation activity by at least 260-fold but only reduced UDP-glucose hydrolytic activity by 4-14-fold. Substitution of aspartate 162 by either serine or asparagine eliminated self-glucosylation activity and reduced UDP-glucose hydrolytic activity by at least 190-fold. The trans-glucosylation of maltose was reduced to undetectable levels in the asparagine 162 mutant, whereas the serine 162 enzyme showed only an 18-30-fold reduction in its ability to trans-glucosylate maltose. These data support a role for aspartate 162 in the chemical step for the glucosyltransferase reaction and a role for aspartate 159 in binding and activating the acceptor molecule. Requirements for catalysis in mammalian glycogenin.,Hurley TD, Stout S, Miner E, Zhou J, Roach PJ J Biol Chem. 2005 Jun 24;280(25):23892-9. Epub 2005 Apr 22. PMID:15849187[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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