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Title | Conformational Landscape of the p28-Bound Human Proteasome Regulatory Particle. |
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Journal, issue, pages | Mol Cell, Vol. 67, Issue 2, Page 322-333.e6, Year 2017 |
Publish date | Jul 20, 2017 |
Authors | Ying Lu / Jiayi Wu / Yuanchen Dong / Shuobing Chen / Shuangwu Sun / Yong-Bei Ma / Qi Ouyang / Daniel Finley / Marc W Kirschner / Youdong Mao / |
PubMed Abstract | The proteasome holoenzyme is activated by its regulatory particle (RP) consisting of two subcomplexes, the lid and the base. A key event in base assembly is the formation of a heterohexameric ring of ...The proteasome holoenzyme is activated by its regulatory particle (RP) consisting of two subcomplexes, the lid and the base. A key event in base assembly is the formation of a heterohexameric ring of AAA-ATPases, which is guided by at least four RP assembly chaperones in mammals: PAAF1, p28/gankyrin, p27/PSMD9, and S5b. Using cryogenic electron microscopy, we analyzed the non-AAA structure of the p28-bound human RP at 4.5 Å resolution and determined seven distinct conformations of the Rpn1-p28-AAA subcomplex within the p28-bound RP at subnanometer resolutions. Remarkably, the p28-bound AAA ring does not form a channel in the free RP and spontaneously samples multiple "open" and "closed" topologies at the Rpt2-Rpt6 and Rpt3-Rpt4 interfaces. Our analysis suggests that p28 assists the proteolytic core particle to select a specific conformation of the ATPase ring for RP engagement and is released in a shoehorn-like fashion in the last step of the chaperone-mediated proteasome assembly. |
External links | Mol Cell / PubMed:28689658 / PubMed Central |
Methods | EM (single particle) |
Resolution | 4.5 - 8.9 Å |
Structure data | EMDB-8672, PDB-5vgz: EMDB-8674, PDB-5vhf: EMDB-8675, PDB-5vhh: EMDB-8676, PDB-5vhi: EMDB-8677, PDB-5vhj: EMDB-8678, PDB-5vhm: EMDB-8679, PDB-5vhn: EMDB-8680, PDB-5vho: EMDB-8681, PDB-5vhp: EMDB-8682, PDB-5vhq: |
Chemicals | ChemComp-ZN: |
Source |
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Keywords | HYDROLASE / p28 / 26S proteasome / regulatory particle / 19S / gankyrin |