View source for 206l


==PHAGE T4 LYSOZYME==
<StructureSection load='206l' size='340' side='right'caption='[[206l]], [[Resolution|resolution]] 1.75&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[206l]] 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=206L OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=206L 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]] 1.75&#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=206l FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=206l OCA], [https://pdbe.org/206l PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=206l RCSB], [https://www.ebi.ac.uk/pdbsum/206l PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=206l 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/06/206l_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=206l ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
In order to determine the thermodynamic cost of introducing a polar group within the core of a protein, a series of nine Ala--&gt;Ser and 3 Val--&gt;Thr substitutions was constructed in T4 lysozyme. The sites were all within alpha-helices but ranged from fully solvent-exposed to totally buried. The range of destabilization incurred by the Ala--&gt;Ser substitutions was found to be very similar to that for the Val--&gt;Thr replacements. For the solvent-exposed and partly exposed sites the destabilization was modest (approximately less than 0.5 kcal/mol). For the completely buried sites the destabilization was larger, but variable (approximately 1-3 kcal/mol). Crystal structure determinations showed that the Ala--&gt;Ser mutant structures were, in general, very similar to their wild-type counterparts, even though the replacements introduce a hydroxyl group. This is in part because the introduced serines are all within alpha-helices and at congested sites can avoid steric clashes with surrounding atoms by making a hydrogen bond to a backbone carbonyl oxygen in the preceding turn of the helix. The three substituted threonine side chains essentially superimpose on their valine counterparts but display somewhat larger conformational adjustments. The results illustrate how a protein structure will adapt in different ways to avoid the presence of an unsatisfied hydrogen bond donor or acceptor. In the most extreme case, Val 149--&gt;Thr, which is also the most destabilizing variant (delta delta G = 2.8 kcal/mol), a water molecule is incorporated in the mutant structure in order to provide a hydrogen-bonding partner. The results are consistent with the view that many hydrogen bonds within proteins contribute only marginally to stability but that noncharged polar groups that lack a hydrogen-bonding partner are very destabilizing (delta delta G approximately greater than 3 kcal/mol). Supportive of other studies, the alpha-helix propensity of alanine is seen to be higher than that of serine (delta delta G = 0.46 +/- 0.04 kcal/mol), while threonine and valine are similar in alpha-helix propensity.

Energetic cost and structural consequences of burying a hydroxyl group within the core of a protein determined from Ala--&gt;Ser and Val--&gt;Thr substitutions in T4 lysozyme.,Blaber M, Lindstrom JD, Gassner N, Xu J, Heinz DW, Matthews BW Biochemistry. 1993 Oct 26;32(42):11363-73. PMID:8218201<ref>PMID:8218201</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 206l" 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: Blaber M]]
[[Category: Matthews BW]]