View source for 1p5c


==Circular permutation of Helix A in T4 lysozyme==
<StructureSection load='1p5c' size='340' side='right'caption='[[1p5c]], [[Resolution|resolution]] 2.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1p5c]] is a 4 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=1P5C OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1P5C 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]] 2.5&#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=1p5c FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1p5c OCA], [https://pdbe.org/1p5c PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1p5c RCSB], [https://www.ebi.ac.uk/pdbsum/1p5c PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1p5c 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/p5/1p5c_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=1p5c ConSurf].
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== Publication Abstract from PubMed ==
In T4 lysozyme, helix A is located at the amino terminus of the sequence but is associated with the C-terminal domain in the folded structure. To investigate the implications of this arrangement for the folding of the protein, we first created a circularly permuted variant with a new amino terminus at residue 12. In effect, this moves the sequence corresponding to helix A from the N- to the C-terminus of the molecule. The protein crystallized nonisomorphously with the wild type but has a very similar structure, showing that the unit consisting of helix A and the C-terminal domain can be reconstituted from a contiguous polypeptide chain. The protein is less stable than the wild type but folds slightly faster. We then produced a second variant in which the helix A sequence was appended at the C-terminus (as in the first variant), but was also restored at the N-terminus (as in the wild type). This variant has two helix A sequences, one at the N-terminus and the other at the C-terminus, each of which can compete for the same site in the folded protein. The crystal structure shows that it is the N-terminal sequence that folds in a manner similar to that of the wild type, whereas the copy at the C-terminus is forced to loop out. The stability of this protein is much closer to that of the wild type, but its rate of folding is significantly slower. The reduction in rate is attributed to the presence of the two identical sequence segments which compete for a single, mutually exclusive, site.

Relocation or duplication of the helix A sequence of T4 lysozyme causes only modest changes in structure but can increase or decrease the rate of folding.,Sagermann M, Baase WA, Mooers BH, Gay L, Matthews BW Biochemistry. 2004 Feb 10;43(5):1296-301. PMID:14756565<ref>PMID:14756565</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 1p5c" 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: Baase WA]]
[[Category: Gay L]]
[[Category: Matthews BW]]
[[Category: Sagermann M]]