1qt3: Difference between revisions

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[[Image:1qt3.jpg|left|200px]]


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==T26D MUTANT OF T4 LYSOZYME==
The line below this paragraph, containing "STRUCTURE_1qt3", creates the "Structure Box" on the page.
<StructureSection load='1qt3' size='340' side='right'caption='[[1qt3]], [[Resolution|resolution]] 1.85&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'>[[1qt3]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_virus_T4 Escherichia virus T4]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QT3 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1QT3 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]] 1.85&#8491;</td></tr>
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<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=HED:2-HYDROXYETHYL+DISULFIDE'>HED</scene></td></tr>
{{STRUCTURE_1qt3| PDB=1qt3 |  SCENE= }}
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1qt3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1qt3 OCA], [https://pdbe.org/1qt3 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1qt3 RCSB], [https://www.ebi.ac.uk/pdbsum/1qt3 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1qt3 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/ENLYS_BPT4 ENLYS_BPT4] Endolysin with lysozyme activity that degrades host peptidoglycans and participates with the holin and spanin proteins in the sequential events which lead to the programmed host cell lysis releasing the mature viral particles. Once the holin has permeabilized the host cell membrane, the endolysin can reach the periplasm and break down the peptidoglycan layer.<ref>PMID:22389108</ref>
== 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/1qt3_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=1qt3 ConSurf].
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'''T26D MUTANT OF T4 LYSOZYME'''
==See Also==
 
*[[Lysozyme 3D structures|Lysozyme 3D structures]]
 
== References ==
==Overview==
<references/>
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.
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</StructureSection>
==About this Structure==
[[Category: Escherichia virus T4]]
1QT3 is a [[Single protein]] structure of 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=1QT3 OCA].
[[Category: Large Structures]]
 
[[Category: Kuroki R]]
==Reference==
[[Category: Matthews BW]]
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:[http://www.ncbi.nlm.nih.gov/pubmed/10430876 10430876]
[[Category: Weaver LH]]
[[Category: Enterobacteria phage t4]]
[[Category: Lysozyme]]
[[Category: Single protein]]
[[Category: Kuroki, R.]]
[[Category: Matthews, B W.]]
[[Category: Weaver, L H.]]
[[Category: Hydrolase]]
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