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| - | [[Image:1n57.gif|left|200px]]<br /><applet load="1n57" size="450" color="white" frame="true" align="right" spinBox="true" | |
| - | caption="1n57, resolution 1.6Å" /> | |
| - | '''Crystal Structure of Chaperone Hsp31'''<br /> | |
| | | | |
| - | ==Overview== | + | ==Crystal Structure of Chaperone Hsp31== |
| - | Heat shock proteins (Hsps) play essential protective roles under stress, conditions by preventing the formation of protein aggregates and degrading, misfolded proteins. EcHsp31, the yedU (hchA) gene product, is a, representative member of a family of chaperones that alleviates protein, misfolding by interacting with early unfolding intermediates. The 1.6-A, crystal structure of the EcHsp31 dimer reveals a system of hydrophobic, patches, canyons, and grooves, which may stabilize partially unfolded, substrate. The presence of a well conserved, yet buried, triad in each, two-domain subunit suggests a still unproven hydrolytic function of the, protein. A flexible extended linker between the A and P domains may play a, role in conformational flexibility and substrate binding. The alpha-beta, sandwich of the EcHsp31 monomer shows structural similarity to PhPI, a, protease belonging to the DJ-1 superfamily. The structure-guided sequence, alignment indicates that Hsp31 homologs can be divided in three classes, based on variations in the P domain that dramatically affect both, oligomerization and catalytic triad formation.
| + | <StructureSection load='1n57' size='340' side='right'caption='[[1n57]], [[Resolution|resolution]] 1.60Å' scene=''> |
| - | | + | == Structural highlights == |
| - | ==About this Structure== | + | <table><tr><td colspan='2'>[[1n57]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1N57 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1N57 FirstGlance]. <br> |
| - | 1N57 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with MG as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1N57 OCA].
| + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.6Å</td></tr> |
| - | | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</scene></td></tr> |
| - | ==Reference== | + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1n57 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1n57 OCA], [https://pdbe.org/1n57 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1n57 RCSB], [https://www.ebi.ac.uk/pdbsum/1n57 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1n57 ProSAT]</span></td></tr> |
| - | The 1.6-A crystal structure of the class of chaperones represented by Escherichia coli Hsp31 reveals a putative catalytic triad., Quigley PM, Korotkov K, Baneyx F, Hol WG, Proc Natl Acad Sci U S A. 2003 Mar 18;100(6):3137-42. Epub 2003 Mar 5. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=12621151 12621151]
| + | </table> |
| | + | == Function == |
| | + | [https://www.uniprot.org/uniprot/HCHA_ECOLI HCHA_ECOLI] Functions as a holding molecular chaperone (holdase) which stabilizes unfolding intermediates and rapidly releases them in an active form once stress has abated. Plays an important role in protecting cells from severe heat shock and starvation, as well as in acid resistance of stationary-phase cells. It uses temperature-induced exposure of structured hydrophobic domains to capture and stabilizes early unfolding and denatured protein intermediates under severe thermal stress. Catalyzes the conversion of methylglyoxal (MG) to D-lactate in a single glutathione (GSH)-independent step. It can also use phenylglyoxal as substrate. Glyoxalase activity protects cells against dicarbonyl stress. Displays an aminopeptidase activity that is specific against peptide substrates with alanine or basic amino acids (lysine, arginine) at N-terminus.<ref>PMID:7848303</ref> <ref>PMID:12235139</ref> <ref>PMID:12565879</ref> <ref>PMID:14731284</ref> <ref>PMID:15550391</ref> <ref>PMID:16796689</ref> <ref>PMID:17158627</ref> <ref>PMID:21696459</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/n5/1n57_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=1n57 ConSurf]. |
| | + | <div style="clear:both"></div> |
| | + | == References == |
| | + | <references/> |
| | + | __TOC__ |
| | + | </StructureSection> |
| | [[Category: Escherichia coli]] | | [[Category: Escherichia coli]] |
| - | [[Category: Single protein]] | + | [[Category: Large Structures]] |
| - | [[Category: Baneyx, F.]] | + | [[Category: Baneyx F]] |
| - | [[Category: Hol, W.G.J.]] | + | [[Category: Hol WGJ]] |
| - | [[Category: Korotkov, K.]] | + | [[Category: Korotkov K]] |
| - | [[Category: Quigley, P.M.]] | + | [[Category: Quigley PM]] |
| - | [[Category: MG]]
| + | |
| - | [[Category: alpha-beta sandwich]]
| + | |
| - | | + | |
| - | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 21:58:18 2007''
| + | |
| Structural highlights
Function
HCHA_ECOLI Functions as a holding molecular chaperone (holdase) which stabilizes unfolding intermediates and rapidly releases them in an active form once stress has abated. Plays an important role in protecting cells from severe heat shock and starvation, as well as in acid resistance of stationary-phase cells. It uses temperature-induced exposure of structured hydrophobic domains to capture and stabilizes early unfolding and denatured protein intermediates under severe thermal stress. Catalyzes the conversion of methylglyoxal (MG) to D-lactate in a single glutathione (GSH)-independent step. It can also use phenylglyoxal as substrate. Glyoxalase activity protects cells against dicarbonyl stress. Displays an aminopeptidase activity that is specific against peptide substrates with alanine or basic amino acids (lysine, arginine) at N-terminus.[1] [2] [3] [4] [5] [6] [7] [8]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
References
- ↑ Misra K, Banerjee AB, Ray S, Ray M. Glyoxalase III from Escherichia coli: a single novel enzyme for the conversion of methylglyoxal into D-lactate without reduced glutathione. Biochem J. 1995 Feb 1;305 ( Pt 3):999-1003. PMID:7848303
- ↑ Sastry MS, Korotkov K, Brodsky Y, Baneyx F. Hsp31, the Escherichia coli yedU gene product, is a molecular chaperone whose activity is inhibited by ATP at high temperatures. J Biol Chem. 2002 Nov 29;277(48):46026-34. Epub 2002 Sep 15. PMID:12235139 doi:http://dx.doi.org/10.1074/jbc.M205800200
- ↑ Malki A, Kern R, Abdallah J, Richarme G. Characterization of the Escherichia coli YedU protein as a molecular chaperone. Biochem Biophys Res Commun. 2003 Feb 7;301(2):430-6. PMID:12565879
- ↑ Mujacic M, Bader MW, Baneyx F. Escherichia coli Hsp31 functions as a holding chaperone that cooperates with the DnaK-DnaJ-GrpE system in the management of protein misfolding under severe stress conditions. Mol Microbiol. 2004 Feb;51(3):849-59. PMID:14731284
- ↑ Malki A, Caldas T, Abdallah J, Kern R, Eckey V, Kim SJ, Cha SS, Mori H, Richarme G. Peptidase activity of the Escherichia coli Hsp31 chaperone. J Biol Chem. 2005 Apr 15;280(15):14420-6. Epub 2004 Nov 18. PMID:15550391 doi:http://dx.doi.org/10.1074/jbc.M408296200
- ↑ Mujacic M, Baneyx F. Regulation of Escherichia coli hchA, a stress-inducible gene encoding molecular chaperone Hsp31. Mol Microbiol. 2006 Jun;60(6):1576-89. PMID:16796689 doi:http://dx.doi.org/10.1111/j.1365-2958.2006.05207.x
- ↑ Mujacic M, Baneyx F. Chaperone Hsp31 contributes to acid resistance in stationary-phase Escherichia coli. Appl Environ Microbiol. 2007 Feb;73(3):1014-8. Epub 2006 Dec 8. PMID:17158627 doi:http://dx.doi.org/10.1128/AEM.02429-06
- ↑ Subedi KP, Choi D, Kim I, Min B, Park C. Hsp31 of Escherichia coli K-12 is glyoxalase III. Mol Microbiol. 2011 Aug;81(4):926-36. doi: 10.1111/j.1365-2958.2011.07736.x. Epub, 2011 Jul 6. PMID:21696459 doi:http://dx.doi.org/10.1111/j.1365-2958.2011.07736.x
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