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| | <StructureSection load='1pv2' size='340' side='right'caption='[[1pv2]], [[Resolution|resolution]] 2.71Å' scene=''> | | <StructureSection load='1pv2' size='340' side='right'caption='[[1pv2]], [[Resolution|resolution]] 2.71Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[1pv2]] is a 8 chain structure with sequence from [http://en.wikipedia.org/wiki/"bacillus_coli"_migula_1895 "bacillus coli" migula 1895]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1PV2 OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=1PV2 FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[1pv2]] is a 8 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=1PV2 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1PV2 FirstGlance]. <br> |
| - | </td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[1n57|1n57]]</div></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]] 2.71Å</td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">HCHA OR B1967 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 "Bacillus coli" Migula 1895])</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=1pv2 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1pv2 OCA], [https://pdbe.org/1pv2 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1pv2 RCSB], [https://www.ebi.ac.uk/pdbsum/1pv2 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1pv2 ProSAT]</span></td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=1pv2 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1pv2 OCA], [http://pdbe.org/1pv2 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1pv2 RCSB], [http://www.ebi.ac.uk/pdbsum/1pv2 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1pv2 ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://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> | + | [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 == | | == Evolutionary Conservation == |
| | [[Image:Consurf_key_small.gif|200px|right]] | | [[Image:Consurf_key_small.gif|200px|right]] |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Bacillus coli migula 1895]] | + | [[Category: Escherichia coli]] |
| | [[Category: Large Structures]] | | [[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: Chaperone]]
| + | |
| - | [[Category: Flexibility]]
| + | |
| - | [[Category: Heat shock protein]]
| + | |
| - | [[Category: Monoclinic]]
| + | |
| - | [[Category: Putative catalytic triad]]
| + | |
| 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.
Publication Abstract from PubMed
Heat shock proteins and proteases play a crucial role in cell survival under conditions of environmental stress. The heat shock protein Hsp31, produced by gene hchA at elevated temperatures in Escherichia coli, is a homodimeric protein consisting of a large A domain and a smaller P domain connected by a linker. Two catalytic triads are present per dimer, with the Cys and His contributed by the A domain and an Asp by the P domain. A new crystal Form II confirms the dimer and catalytic triad arrangement seen in the earlier crystal Form I. In addition, several loops exhibit increased flexibility compared to the previous Hsp31 dimer structure. In particular, loops D2 and D3 are intriguing because their mobility leads to the exposure of a sizable hydrophobic patch made up by surface areas of both subunits near the dimer interface. The residues creating this hydrophobic surface are completely conserved in the Hsp31 family. At the same time, access to the catalytic triad is increased. These observations lead to the hypothesis for the functioning of Hsp31 wherein loops D2 and D3 play a key role: first, at elevated temperatures, by becoming mobile and uncovering a large hydrophobic area that helps in binding to client proteins, and second, by removing the client protein from the hydrophobic patch when the temperature decreases and the loops adopt their low-temperature positions at the Hsp31 surface. The proposed mode of action of flexible loops in the functioning of Hsp31 may be a general principle employed by other chaperones.
A new native EcHsp31 structure suggests a key role of structural flexibility for chaperone function.,Quigley PM, Korotkov K, Baneyx F, Hol WG Protein Sci. 2004 Jan;13(1):269-77. PMID:14691241[9]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
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
- ↑ Quigley PM, Korotkov K, Baneyx F, Hol WG. A new native EcHsp31 structure suggests a key role of structural flexibility for chaperone function. Protein Sci. 2004 Jan;13(1):269-77. PMID:14691241
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