Dimer structure as a minimum cooperative subunit of small heat-shock proteins.

Abstract

Recently, it has been shown that small heat-shock proteins (Hsp25, Hsp27) are molecular chaperones. They bind to thermally unfolded proteins and can also assist refolding of denatured proteins. Mammalian small Hsps can form oligomeric structures of about 32 subunits. Until now, no data about cooperativity and stability of the interactions between the subunits of sHsps are available. To analyze these interactions we studied mouse Hsp25 and human Hsp27 by difference adiabatic scanning microcalorimetry (DASM) and circular dichroism (CD). Here we show that, according to DASM data, the minimum cooperatively melting structure is a sHsp-dimer. CD data indicate that Hsp25 major secondary structure, the beta-pleated conformation, is resistant to acidic influence up to pH 4.5 and, at neutral pH values, to heat treatment up to 60 degrees C. The melting pattern of Hsp25/27 bears resemblance to alpha-crystallins. CD data indicate similar secondary, tertiary and quaternary structures of the proteins compared. This finding is in agreement with the revealed homology of primary structure of these proteins and their common chaperone function. Study holds ProTherm entries: 7328, 7329 Extra Details: transition 1 heat-shock protein; calorimetry; structure homology

Submission Details

ID: 9ndc5YDH

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:33 p.m.

Version: 1

Publication Details
Dudich IV;Zav'yalov VP;Pfeil W;Gaestel M;Zav'yalova GA;Denesyuk AI;Korpela T,Biochim. Biophys. Acta (1995) Dimer structure as a minimum cooperative subunit of small heat-shock proteins. PMID:8519797
Additional Information

Study Summary

Number of data points 2
Proteins 60 kDa heat shock protein, mitochondrial
Unique complexes 1
Assays/Quantities/Protocols Experimental Assay: Tm
Libraries Mutations for sequence MLRLPTVLRQMRPVSRALAPHLTRAYAKDVKFGADARALMLQGVDLLADAVAVTMGPKGRTVIIEQSWGSPKVTKDGVTVAKSIDLKDKYKNIGAKLVQDVANNTNEEAGDGTTTATVLARSIAKEGFEKISKGANPVEIRRGVMLAVDAVIAELKKQSKPVTTPEEIAQVATISANGDKDIGNIISDAMKKVGRKGVITVKDGKTLNDELEIIEGMKFDRGYISPYFINTSKGQKCEFQDAYVLLSEKKISSVQSIVPALEIANAHRKPLVIIAEDVDGEALSTLVLNRLKVGLQVVAVKAPGFGDNRKNQLKDMAIATGGAVFGEEGLNLNLEDVQAHDLGKVGEVIVTKDDAMLLKGKGDKAHIEKRIQEITEQLDITTSEYEKEKLNERLAKLSDGVAVLKVGGTSDVEVNEKKDRVTDALNATRAAVEEGIVLGGGCALLRCIPALDSLKPANEDQKIGIEIIKRALKIPAMTIAKNAGVEGSLIVEKILQSSSEVGYDAMLGDFVNMVEKGIIDPTKVVRTALLDAAGVASLLTTAEAVVTEIPKEEKDPGMGAMGGMGGGMGGGMF

Study data

No weblogo for data of varying length.
Colors: D E R H K S T N Q A V I L M F Y W C G P
 

Data Distribution

Studies with similar sequences (approximate matches)

Correlation with other assays (exact sequence matches)


Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 60 kDa heat shock protein, mitochondrial P63038 CH60_MOUSE
100.0 60 kDa heat shock protein, mitochondrial P63039 CH60_RAT
98.9 60 kDa heat shock protein, mitochondrial P18687 CH60_CRIGR
97.5 60 kDa heat shock protein, mitochondrial P10809 CH60_HUMAN
97.0 60 kDa heat shock protein, mitochondrial Q5NVM5 CH60_PONAB
96.9 60 kDa heat shock protein, mitochondrial P31081 CH60_BOVIN
94.7 60 kDa heat shock protein, mitochondrial Q5ZL72 CH60_CHICK