View source for 3usq


==Structure of D159S/Y194F glycogenin mutant truncated at residue 270==
<StructureSection load='3usq' size='340' side='right'caption='[[3usq]], [[Resolution|resolution]] 2.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3usq]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/European_rabbit European rabbit]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3USQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3USQ FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[1ll0|1ll0]], [[1ll2|1ll2]], [[1ll3|1ll3]], [[1zct|1zct]], [[1zcu|1zcu]], [[1zcv|1zcv]], [[1zcy|1zcy]], [[3uns|3uns]]</div></td></tr>
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">GYG, GYG1 ([https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9986 European rabbit])</td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/Glycogenin_glucosyltransferase Glycogenin glucosyltransferase], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.4.1.186 2.4.1.186] </span></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=3usq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3usq OCA], [https://pdbe.org/3usq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3usq RCSB], [https://www.ebi.ac.uk/pdbsum/3usq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3usq 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. 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Initiation of glucose polymerization by glycogenin autoglucosylation at Tyr-194 is required to prime de novo biosynthesis of glycogen. It has been proposed that the synthesis of the primer proceeds by intersubunit glucosylation of dimeric glycogenin, even though it has not been demonstrated that this mechanism is responsible for the described polymerization extent of 12 glucoses produced by the dimer. We reported previously the intramonomer glucosylation capability of glycogenin without determining the extent of autoglucopolymerization. Here, we show that the maximum specific autoglucosylation extent (MSAE) produced by the non-glucosylated glycogenin monomer is 13.3 +/- 1.9 glucose units, similar to the 12.5 +/- 1.4 glucose units measured for the dimer. The mechanism and capacity of the dimeric enzyme to carry out full glucopolymerization were also evaluated by construction of heterodimers able to glucosylate exclusively by intrasubunit or intersubunit reaction mechanisms. The MSAE of non-glucosylated glycogenin produced by dimer intrasubunit glucosylation was 16% of that produced by the monomer. However, partially glucosylated glycogenin was able to almost complete its autoglucosylation by the dimer intrasubunit mechanism. The MSAE produced by heterodimer intersubunit glucosylation was 60% of that produced by the wild-type dimer. We conclude that both intrasubunit and intersubunit reaction mechanisms are necessary for the dimeric enzyme to acquire maximum autoglucosylation. The full glucopolymerization capacity of monomeric glycogenin indicates that the enzyme is able to synthesize the glycogen primer without the need for prior dimerization.

Mechanisms of monomeric and dimeric glycogenin autoglucosylation.,Issoglio FM, Carrizo ME, Romero JM, Curtino JA J Biol Chem. 2012 Jan 13;287(3):1955-61. Epub 2011 Nov 29. PMID:22128147<ref>PMID:22128147</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 3usq" style="background-color:#fffaf0;"></div>

==See Also==
*[[Glycogenin|Glycogenin]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: European rabbit]]
[[Category: Glycogenin glucosyltransferase]]
[[Category: Large Structures]]
[[Category: Carrizo, M E]]
[[Category: Curtino, J A]]
[[Category: Issoglio, F M]]
[[Category: Romero, J M]]
[[Category: Glucosyltransferase]]
[[Category: Transferase]]