| 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 (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.
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:12621151[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. The 1.6-A crystal structure of the class of chaperones represented by Escherichia coli Hsp31 reveals a putative catalytic triad. Proc Natl Acad Sci U S A. 2003 Mar 18;100(6):3137-42. Epub 2003 Mar 5. PMID:12621151 doi:10.1073/pnas.0530312100
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