Structural analysis of the ribosome-associated complex (RAC) reveals an unusual Hsp70/Hsp40 interaction
Yeast Zuotin and Ssz are members of the conserved Hsp40 and Hsp70 chaperone families, respectively, but compared with canonical homologs, they atypically form a stable heterodimer termed ribosome-associated complex (RAC). RAC acts as co-chaperone for another Hsp70 to assist de novo protein folding....
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| Hauptverfasser: | , , , , , , |
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| Dokumenttyp: | Article (Journal) |
| Sprache: | Englisch |
| Veröffentlicht: |
29 January 2010
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| In: |
The journal of biological chemistry
Year: 2010, Jahrgang: 285, Heft: 5, Pages: 3227-3234 |
| ISSN: | 1083-351X |
| DOI: | 10.1074/jbc.M109.075804 |
| Online-Zugang: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1074/jbc.M109.075804 Verlag, lizenzpflichtig, Volltext: https://www.sciencedirect.com/science/article/pii/S0021925820648177 
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| Verfasserangaben: | Jocelyne Fiaux, Janina Horst, Annika Scior, Steffen Preissler, Ansgar Koplin, Bernd Bukau, and Elke Deuerling |
| Zusammenfassung: | Yeast Zuotin and Ssz are members of the conserved Hsp40 and Hsp70 chaperone families, respectively, but compared with canonical homologs, they atypically form a stable heterodimer termed ribosome-associated complex (RAC). RAC acts as co-chaperone for another Hsp70 to assist de novo protein folding. In this study, we identified the molecular basis for the unusual Hsp70/Hsp40 pairing using amide hydrogen exchange (HX) coupled with mass spectrometry and mutational analysis. Association of Ssz with Zuotin strongly decreased the conformational dynamics mainly in the C-terminal domain of Ssz, whereas Zuotin acquired strong conformational stabilization in its N-terminal segment. Deletion of the highly flexible N terminus of Zuotin abolished stable association with Ssz in vitro and caused a phenotype resembling the loss of Ssz function in vivo. Thus, the C-terminal domain of Ssz, the N-terminal extension of Zuotin, and their mutual stabilization are the major structural determinants for RAC assembly. We furthermore found dynamic changes in the J-domain of Zuotin upon complex formation that might be crucial for RAC co-chaperone function. Taken together, we present a novel mechanism for converting Zuotin and Ssz chaperones into a functionally active dimer. |
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| Beschreibung: | Online veröffentlicht am 17. November 2009 Gesehen am 23.10.2023 |
| Beschreibung: | Online Resource |
| ISSN: | 1083-351X |
| DOI: | 10.1074/jbc.M109.075804 |