Conformational landscape of the 26S proteasome gives insights into the CP gate-opening
− この都医学研セミナーは終了しました。 −
| 演者 |
Eri Sakata Department of Molecular Structural Biology, Max Planck Institute of Biochemistry（Project Group leader） |
|---|---|
| 会場 | 東京都医学総合研究所 2階講堂 |
| 日時 | 平成30年3月13日（火）15：00～ |
| 世話人 | 田中 啓二 （東京都医学総合研究所 所長） |
| 参加自由 | 詳細は下記問合せ先まで |
| お問い合わせ |
研究推進課 普及広報係 電話 03-5316-3109 |
講演要旨
26S proteasome is a 2.5 MDa protein complex that is composed of a catalytic 20S core particle (CP) and 19S regulatory particles (RPs) containing hexameric AAA+ ATPase ring. Entry of the substrates into the CP is regulated by N-termini of α subunits. However, the fundamental mechanism by which the RP controls the CP gate-opening remains unclear. We sought to understand the gate-opening mechanism and analyzed structures of the 26S proteasome by single-particle cryo-electron microscopy (cryo-EM). Addition of different nucleotide analogs led us to identify several novel conformations in which the CP gate is open. High resolution open-gate structures help to understand how the proteasome gate is regulated by the AAA+ ATPases. In addition to the HbYX-motif insertions, engagement of the C-termini of Rpt1 and Rpt6 are necessary to open the CP gate. These insertions induce the conformational change of α2 and α4 subunits, resulting in the rearrangement of the N-termini of α subunits.
