View source for 1l01


==STRUCTURAL STUDIES OF MUTANTS OF THE LYSOZYME OF BACTERIOPHAGE T4. THE TEMPERATURE-SENSITIVE MUTANT PROTEIN THR157 (RIGHT ARROW) ILE==
<StructureSection load='1l01' size='340' side='right'caption='[[1l01]], [[Resolution|resolution]] 1.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1l01]] 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=1L01 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1L01 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]] 1.7&#8491;</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=1l01 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1l01 OCA], [https://pdbe.org/1l01 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1l01 RCSB], [https://www.ebi.ac.uk/pdbsum/1l01 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1l01 ProSAT]</span></td></tr>
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== 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/l0/1l01_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=1l01 ConSurf].
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== Publication Abstract from PubMed ==
To understand the roles of individual amino acids in the folding and stability of globular proteins, a systematic structural analysis of mutants of the lysozyme of bacteriophage T4 has been undertaken. The isolation, characterization, crystallographic refinement and structural analysis of a temperature-sensitive lysozyme in which threonine 157 is replaced by isoleucine is reported here. This mutation reduces the temperature of the midpoint of the reversible thermal denaturation transition by 11 deg.C at pH 2.0. Electron density maps showing differences between the wild-type and mutant X-ray crystal structures have obvious features corresponding to the substitution of threonine 157 by isoleucine. There is little difference electron density in the remainder of the molecule, indicating that the structural changes are localized to the site of the mutation. High-resolution crystallographic refinement of the mutant lysozyme structure confirms that it is very similar to wild-type lysozyme. The largest conformational differences are in the gamma-carbon of residue 157 and in the side-chain of Asp159, which shift 1.0 A and 1.1 A, respectively. In the wild-type enzyme, the gamma-hydroxyl group of Thr157 participates in a network of hydrogen bonds. Substitution of Thr157 with an isoleucine disrupts this set of hydrogen bonds. A water molecule bound in the vicinity of Thr155 partially restores the hydrogen bond network in the mutant structure, but the buried main-chain amide of Asp159 is not near a hydrogen bond acceptor. This unsatisfied hydrogen-bonding potential is the most obvious reason for the reduction in stability of the temperature-sensitive mutant protein.

Structural studies of mutants of the lysozyme of bacteriophage T4. The temperature-sensitive mutant protein Thr157----Ile.,Grutter MG, Gray TM, Weaver LH, Wilson TA, Matthews BW J Mol Biol. 1987 Sep 20;197(2):315-29. PMID:3681997<ref>PMID:3681997</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Lysozyme 3D structures|Lysozyme 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia virus T4]]
[[Category: Large Structures]]
[[Category: Alber T]]
[[Category: Dao-Pin S]]
[[Category: Matthews BW]]