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| | ==ANALYSIS OF THE INTERACTION BETWEEN CHARGED SIDE CHAINS AND THE ALPHA-HELIX DIPOLE USING DESIGNED THERMOSTABLE MUTANTS OF PHAGE T4 LYSOZYME== | | ==ANALYSIS OF THE INTERACTION BETWEEN CHARGED SIDE CHAINS AND THE ALPHA-HELIX DIPOLE USING DESIGNED THERMOSTABLE MUTANTS OF PHAGE T4 LYSOZYME== |
| - | <StructureSection load='1l56' size='340' side='right' caption='[[1l56]], [[Resolution|resolution]] 1.80Å' scene=''> | + | <StructureSection load='1l56' size='340' side='right'caption='[[1l56]], [[Resolution|resolution]] 1.80Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[1l56]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Bpt4 Bpt4]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1L56 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1L56 FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[1l56]] 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=1L56 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1L56 FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=BME:BETA-MERCAPTOETHANOL'>BME</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.8Å</td></tr> |
| - | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[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] </span></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></td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1l56 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1l56 OCA], [http://pdbe.org/1l56 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1l56 RCSB], [http://www.ebi.ac.uk/pdbsum/1l56 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1l56 ProSAT]</span></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=1l56 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1l56 OCA], [https://pdbe.org/1l56 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1l56 RCSB], [https://www.ebi.ac.uk/pdbsum/1l56 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1l56 ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/LYS_BPT4 LYS_BPT4]] Helps to release the mature phage particles from the cell wall by breaking down the peptidoglycan. | + | [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 == | | == Evolutionary Conservation == |
| | [[Image:Consurf_key_small.gif|200px|right]] | | [[Image:Consurf_key_small.gif|200px|right]] |
| | Check<jmol> | | Check<jmol> |
| | <jmolCheckbox> | | <jmolCheckbox> |
| - | <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/l5/1l56_consurf.spt"</scriptWhenChecked> | + | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/l5/1l56_consurf.spt"</scriptWhenChecked> |
| - | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | + | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked> |
| | <text>to colour the structure by Evolutionary Conservation</text> | | <text>to colour the structure by Evolutionary Conservation</text> |
| | </jmolCheckbox> | | </jmolCheckbox> |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Bpt4]] | + | [[Category: Escherichia virus T4]] |
| - | [[Category: Lysozyme]] | + | [[Category: Large Structures]] |
| - | [[Category: Matthews, B W]] | + | [[Category: Matthews BW]] |
| - | [[Category: Nicholson, H]] | + | [[Category: Nicholson H]] |
| Structural highlights
Function
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.[1]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
It was previously shown that the two replacements Gly 77-->Ala (G77A) and Ala 82-->Pro (A82P) increase the thermostability of phage T4 lysozyme at pH 6.5. Such replacements are presumed to restrict the degrees of freedom of the unfolded protein and so decrease the entropy of unfolding [B. W. Matthews, H. Nicholson, and W. J. Becktel (1987) Proceedings of the National Academy of Science USA Vol. 84, pp. 6663-6667]. To further test this approach, three additional replacements--G113A, K60P and A93P--have been constructed. On the basis of model building, each of these three replacements was judged to be less than optimal because it would tend to introduce unfavorable van der Waals contacts with neighboring parts of the protein. The presence of such contacts was verified for G113A and K60P by conformational adjustments seen in the crystal structures of these mutant proteins. In the case of G113A there are backbone conformational changes of 0.5-1.0 A in the short alpha-helix, 108-113, that includes the site of substitution. In the case of K60P the pyrrolidine ring shows evidence of strain. The thermal stability of each of the three variants at both pH 2.0 and pH 6.5 was found to be very close to that of wild-type lysozyme. The results suggest that the procedure used to predict sites for both Xaa-->Pro and Gly-->Ala is, in principle, correct. At the same time, the increase in stability expected from substitutions of this type is modest, and can easily be offset by strain associated with introduction of the alanine or proline. This means that the criteria used to select substitutions that will increase thermostability have to be stringent at least. In the case of T4 lysozyme this severely limits the number of sites. The analysis reveals a significant discrepancy between the conformational energy surface predicted for the residue preceding a proline and the conformations observed in crystal structures.
Analysis of the effectiveness of proline substitutions and glycine replacements in increasing the stability of phage T4 lysozyme.,Nicholson H, Tronrud DE, Becktel WJ, Matthews BW Biopolymers. 1992 Nov;32(11):1431-41. PMID:1457724[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Moussa SH, Kuznetsov V, Tran TA, Sacchettini JC, Young R. Protein determinants of phage T4 lysis inhibition. Protein Sci. 2012 Apr;21(4):571-82. doi: 10.1002/pro.2042. Epub 2012 Mar 2. PMID:22389108 doi:http://dx.doi.org/10.1002/pro.2042
- ↑ Nicholson H, Tronrud DE, Becktel WJ, Matthews BW. Analysis of the effectiveness of proline substitutions and glycine replacements in increasing the stability of phage T4 lysozyme. Biopolymers. 1992 Nov;32(11):1431-41. PMID:1457724 doi:http://dx.doi.org/10.1002/bip.360321103
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