Hsp31, the Escherichia coli yedU Gene Product, Is a Molecular Chaperone Whose Activity Is Inhibited by ATP at High Temperatures

The Escherichia coli chromosome contains several uncharacterized heat-inducible loci that may encode novel molecular chaperones or proteases. Here we show that the 31-kDa product of the yedU gene is an efficient homodimeric molecular chaperone that is conserved in a number of pathogenic eubacteria a...

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Veröffentlicht in:The Journal of biological chemistry 2002-11, Vol.277 (48), p.46026-46034
Hauptverfasser: Sastry, M S R, Korotkov, Konstantin, Brodsky, Yan, Baneyx, Francois
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Sprache:eng
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Zusammenfassung:The Escherichia coli chromosome contains several uncharacterized heat-inducible loci that may encode novel molecular chaperones or proteases. Here we show that the 31-kDa product of the yedU gene is an efficient homodimeric molecular chaperone that is conserved in a number of pathogenic eubacteria and fungi. Heat shock protein (Hsp) 31 relies on temperature-driven conformational changes to expose structured hydrophobic domains that are likely responsible for substrate binding. Complementing the function of refolding, remodeling, and holding chaperones, Hsp 31 preferentially interacts with early unfolding intermediates and rapidly releases them in an active form after transfer to low temperatures. Although Hsp 31 does not appear to exhibit intrinsic ATPase activity, binding of ATP at high temperatures restricts the size or availability of the substrate binding site, thereby modulating chaperone activity. The possible role of ATP in coordinating the function of the cellular complement of molecular chaperones is discussed.
ISSN:0021-9258
1083-351X
DOI:10.1074/jbc.M205800200