254l: Difference between revisions
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== | ==LYSOZYME== | ||
<StructureSection load='254l' size='340' side='right'caption='[[254l]], [[Resolution|resolution]] 1.90Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[254l]] 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=254L OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=254L 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]] 1.9Å</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=254l FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=254l OCA], [https://pdbe.org/254l PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=254l RCSB], [https://www.ebi.ac.uk/pdbsum/254l PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=254l 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/54/254l_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=254l 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. | 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. | ||
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> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 254l" style="background-color:#fffaf0;"></div> | |||
==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]] | |||