1qt8: Difference between revisions

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-[[Image:1qt8.png|left|200px]]
+==T26H Mutant of T4 Lysozyme==
+<StructureSection load='1qt8' size='340' side='right' caption='[[1qt8]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
+== Structural highlights ==
+<table><tr><td colspan='2'>[[1qt8]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Enterobacteria_phage_t4 Enterobacteria phage t4]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QT8 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1QT8 FirstGlance]. <br>
+</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=HED:2-HYDROXYETHYL+DISULFIDE'>HED</scene><br>
+<tr><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1qtv|1qtv]], [[1qtz|1qtz]], [[1qt3|1qt3]], [[1qt4|1qt4]], [[1qt5|1qt5]], [[1qt6|1qt6]], [[1qt7|1qt7]]</td></tr>
+<tr><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Lysozyme Lysozyme], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.17 3.2.1.17] </span></td></tr>
+<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1qt8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1qt8 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1qt8 RCSB], [http://www.ebi.ac.uk/pdbsum/1qt8 PDBsum]</span></td></tr>
+<table>
+== 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/qt/1qt8_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/chain_selection.php?pdb_ID=2ata ConSurf].
+<div style="clear:both"></div>
+<div style="background-color:#fffaf0;">
+== Publication Abstract from PubMed ==
+In contrast to hen egg-white lysozyme, which retains the beta-configuration of the substrate in the product, T4 lysozyme (T4L) is an inverting glycosidase. The substitution Thr-26 --&gt; His, however, converts T4L from an inverting to a retaining enzyme. It is shown here that the Thr-26 --&gt; His mutant is also a transglycosidase. Indeed, the transglycosylation reaction can be more effective than hydrolysis. In contrast, wild-type T4L has no detectable transglycosidase activity. The results support the prior hypothesis that catalysis by the Thr-26 --&gt; His mutant proceeds via a covalent intermediate. Further mutations (Glu-11 --&gt; His, Asp-20 --&gt; Cys) of the T26H mutant lysozyme indicate that the catalytic mechanism of this mutant requires Glu-11 as a general acid but Asp-20 is not essential. The results help provide an overall rationalization for the activity of glycosidases, in which a highly conserved acid group (Glu-11 in T4L, Glu-35 in hen egg-white lysozyme) on the beta-side of the substrate acts as a proton donor, whereas alterations in the placement and chemical identity of residues on the alpha-side of the substrate can lead to catalysis with or without retention of the configuration, to transglycosidase activity, or to the formation of a stable enzyme-substrate adduct.
-{{STRUCTURE_1qt8|  PDB=1qt8  |  SCENE=  }}
+Structural basis of the conversion of T4 lysozyme into a transglycosidase by reengineering the active site.,Kuroki R, Weaver LH, Matthews BW Proc Natl Acad Sci U S A. 1999 Aug 3;96(16):8949-54. PMID:10430876<ref>PMID:10430876</ref>
-===T26H Mutant of T4 Lysozyme===
+From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
+</div>
-{{ABSTRACT_PUBMED_10430876}}
-==About this Structure==
-[[1qt8]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Enterobacteria_phage_t4 Enterobacteria phage t4]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QT8 OCA].
 ==See Also==
-*[[Hen Egg-White (HEW) Lysozyme|Hen Egg-White (HEW) Lysozyme]]
+*[[Lysozyme 3D structures|Lysozyme 3D structures]]
+== References ==
-==Reference==
+<references/>
-<ref group="xtra">PMID:010430876</ref><references group="xtra"/>
+__TOC__
+</StructureSection>
 [[Category: Enterobacteria phage t4]]
 [[Category: Lysozyme]]