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-Structure paper
タイトル | Structures of chaperone-associated assembly intermediates reveal coordinated mechanisms of proteasome biogenesis. |
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ジャーナル・号・ページ | Nat Struct Mol Biol, Vol. 28, Issue 5, Page 418-425, Year 2021 |
掲載日 | 2021年4月12日 |
著者 | Helena M Schnell / Richard M Walsh / Shaun Rawson / Mandeep Kaur / Meera K Bhanu / Geng Tian / Miguel A Prado / Angel Guerra-Moreno / Joao A Paulo / Steven P Gygi / Jeroen Roelofs / Daniel Finley / John Hanna / |
PubMed 要旨 | The proteasome mediates most selective protein degradation. Proteolysis occurs within the 20S core particle (CP), a barrel-shaped chamber with an αββα configuration. CP biogenesis proceeds ...The proteasome mediates most selective protein degradation. Proteolysis occurs within the 20S core particle (CP), a barrel-shaped chamber with an αββα configuration. CP biogenesis proceeds through an ordered multistep pathway requiring five chaperones, Pba1-4 and Ump1. Using Saccharomyces cerevisiae, we report high-resolution structures of CP assembly intermediates by cryogenic-electron microscopy. The first structure corresponds to the 13S particle, which consists of a complete α-ring, partial β-ring (β2-4), Ump1 and Pba1/2. The second structure contains two additional subunits (β5-6) and represents a later pre-15S intermediate. These structures reveal the architecture and positions of Ump1 and β2/β5 propeptides, with important implications for their functions. Unexpectedly, Pba1's N terminus extends through an open CP pore, accessing the CP interior to contact Ump1 and the β5 propeptide. These results reveal how the coordinated activity of Ump1, Pba1 and the active site propeptides orchestrate key aspects of CP assembly. |
リンク | Nat Struct Mol Biol / PubMed:33846632 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 2.74 - 3.61 Å |
構造データ | EMDB-23502, PDB-7ls5: EMDB-23503, PDB-7ls6: EMDB-23508, PDB-7lsx: |
由来 |
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キーワード | HYDROLASE (加水分解酵素) / core particle (ヌクレオソーム) / complex / assembly intermediate |