National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI)
DP5-OD019800
米国
引用
ジャーナル: Nat Struct Mol Biol / 年: 2021 タイトル: Structures of chaperone-associated assembly intermediates reveal coordinated mechanisms of proteasome biogenesis. 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 / 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.
名称: 13S / タイプ: complex / ID: 1 / 親要素: 0 / 含まれる分子: all 詳細: Abundant sub-20S particle that is naturally enriched in Pre3-1 mutant (G34D) was purified via C-terminal Pre1-TEV-ProA affinity tag inserted at the endogenous locus.