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-Structure paper
Title | Reconfiguration of the proteasome during chaperone-mediated assembly. |
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Journal, issue, pages | Nature, Vol. 497, Issue 7450, Page 512-516, Year 2013 |
Publish date | May 23, 2013 |
Authors | Soyeon Park / Xueming Li / Ho Min Kim / Chingakham Ranjit Singh / Geng Tian / Martin A Hoyt / Scott Lovell / Kevin P Battaile / Michal Zolkiewski / Philip Coffino / Jeroen Roelofs / Yifan Cheng / Daniel Finley / |
PubMed Abstract | The proteasomal ATPase ring, comprising Rpt1-Rpt6, associates with the heptameric α-ring of the proteasome core particle (CP) in the mature proteasome, with the Rpt carboxy-terminal tails inserting ...The proteasomal ATPase ring, comprising Rpt1-Rpt6, associates with the heptameric α-ring of the proteasome core particle (CP) in the mature proteasome, with the Rpt carboxy-terminal tails inserting into pockets of the α-ring. Rpt ring assembly is mediated by four chaperones, each binding a distinct Rpt subunit. Here we report that the base subassembly of the Saccharomyces cerevisiae proteasome, which includes the Rpt ring, forms a high-affinity complex with the CP. This complex is subject to active dissociation by the chaperones Hsm3, Nas6 and Rpn14. Chaperone-mediated dissociation was abrogated by a non-hydrolysable ATP analogue, indicating that chaperone action is coupled to nucleotide hydrolysis by the Rpt ring. Unexpectedly, synthetic Rpt tail peptides bound α-pockets with poor specificity, except for Rpt6, which uniquely bound the α2/α3-pocket. Although the Rpt6 tail is not visualized within an α-pocket in mature proteasomes, it inserts into the α2/α3-pocket in the base-CP complex and is important for complex formation. Thus, the Rpt-CP interface is reconfigured when the lid complex joins the nascent proteasome to form the mature holoenzyme. |
External links | Nature / PubMed:23644457 / PubMed Central |
Methods | EM (single particle) / X-ray diffraction |
Resolution | 5 - 9.6 Å |
Structure data | EMDB-5593: EMDB-5611: EMDB-5612: EMDB-5613: EMDB-5614: EMDB-5615: EMDB-5616: EMDB-5617: PDB-4jpo: |
Source |
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Keywords | CHAPERONE/HYDROLASE / Hsm3 / Chaperone / Proteasome / Protein Complex / CHAPERONE-HYDROLASE complex |