253l: Difference between revisions

New page: left|200px<br /><applet load="253l" size="450" color="white" frame="true" align="right" spinBox="true" caption="253l, resolution 2.0Å" /> '''LYSOZYME'''<br /> ==...
 
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'''LYSOZYME'''<br />


==Overview==
==LYSOZYME==
Enzymes are thought to use their ordered structures to facilitate, catalysis. A corollary of this theory suggests that enzyme residues, involved in function are not optimized for stability. We tested this, hypothesis by mutating functionally important residues in the active site, of T4 lysozyme. Six mutations at two catalytic residues, Glu-11 and, Asp-20, abolished or reduced enzymatic activity but increased thermal, stability by 0.7-1.7 kcal.mol-1. Nine mutations at two substrate-binding, residues, Ser-117 and Asn-132, increased stability by 1.2-2.0 kcal.mol-1, again at the cost of reduced activity. X-ray crystal structures show that, the substituted residues complement regions of the protein surface that, are used for substrate recognition in the native enzyme. In two of these, structures the enzyme undergoes a general conformational change, similar, to that seen in an enzyme-product complex. These results support a, relationship between stability and function for T4 lysozyme. Other, evidence suggests that the relationship is general.
<StructureSection load='253l' size='340' side='right'caption='[[253l]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[253l]] 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=253L OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=253L 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&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BME:BETA-MERCAPTOETHANOL'>BME</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</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=253l FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=253l OCA], [https://pdbe.org/253l PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=253l RCSB], [https://www.ebi.ac.uk/pdbsum/253l PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=253l 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/53/253l_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=253l ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Enzymes are thought to use their ordered structures to facilitate catalysis. A corollary of this theory suggests that enzyme residues involved in function are not optimized for stability. We tested this hypothesis by mutating functionally important residues in the active site of T4 lysozyme. Six mutations at two catalytic residues, Glu-11 and Asp-20, abolished or reduced enzymatic activity but increased thermal stability by 0.7-1.7 kcal.mol-1. Nine mutations at two substrate-binding residues, Ser-117 and Asn-132, increased stability by 1.2-2.0 kcal.mol-1, again at the cost of reduced activity. X-ray crystal structures show that the substituted residues complement regions of the protein surface that are used for substrate recognition in the native enzyme. In two of these structures the enzyme undergoes a general conformational change, similar to that seen in an enzyme-product complex. These results support a relationship between stability and function for T4 lysozyme. Other evidence suggests that the relationship is general.


==About this Structure==
A relationship between protein stability and protein function.,Shoichet BK, Baase WA, Kuroki R, Matthews BW Proc Natl Acad Sci U S A. 1995 Jan 17;92(2):452-6. PMID:7831309<ref>PMID:7831309</ref>
253L is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacteriophage_t4 Bacteriophage t4] with CL and BME as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [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] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=253L OCA].


==Reference==
From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
A relationship between protein stability and protein function., Shoichet BK, Baase WA, Kuroki R, Matthews BW, Proc Natl Acad Sci U S A. 1995 Jan 17;92(2):452-6. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=7831309 7831309]
</div>
[[Category: Bacteriophage t4]]
<div class="pdbe-citations 253l" style="background-color:#fffaf0;"></div>
[[Category: Lysozyme]]
[[Category: Single protein]]
[[Category: Kuroki, R.]]
[[Category: Matthews, B.W.]]
[[Category: Shoichet, B.]]
[[Category: Weaver, L.H.]]
[[Category: BME]]
[[Category: CL]]
[[Category: bacteriolytic enzyme]]
[[Category: glycosidase]]
[[Category: hydrolase]]


''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Wed Nov 21 07:49:53 2007''
==See Also==
*[[Lysozyme 3D structures|Lysozyme 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia virus T4]]
[[Category: Large Structures]]
[[Category: Kuroki R]]
[[Category: Matthews BW]]
[[Category: Shoichet B]]
[[Category: Weaver LH]]

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