7E55

Cryo-EM structure of alpha 7 homo-tetradecamer

7E55 の概要

• エントリーDOI: 10.2210/pdb7e55/pdb
• EMDBエントリー: 30990
• 分子名称: Proteasome subunit alpha type-3 (1 entity in total)
• 機能のキーワード: conformational fluctuation, double-ring, proteasome, d7 symmetry, chaperone, lyase
• 由来する生物種: Homo sapiens (Human)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 28469.25

構造登録者

Song, C.,Murata, K. (登録日: 2021-02-17, 公開日: 2021-05-05, 最終更新日: 2024-10-30)

主引用文献

Song, C.,Satoh, T.,Sekiguchi, T.,Kato, K.,Murata, K.
Structural Fluctuations of the Human Proteasome alpha 7 Homo-Tetradecamer Double Ring Imply the Proteasomal alpha-Ring Assembly Mechanism.
Int J Mol Sci, 22:-, 2021

PubMed Abstract: The 20S proteasome, which is composed of layered α and β heptameric rings, is the core complex of the eukaryotic proteasome involved in proteolysis. The α7 subunit is a component of the α ring, and it self-assembles into a homo-tetradecamer consisting of two layers of α7 heptameric rings. However, the structure of the α7 double ring in solution has not been fully elucidated. We applied cryo-electron microscopy to delineate the structure of the α7 double ring in solution, revealing a structure different from the previously reported crystallographic model. The D7-symmetrical double ring was stacked with a 15° clockwise twist and a separation of 3 Å between the two rings. Two more conformations, dislocated and fully open, were also identified. Our observations suggest that the α7 double-ring structure fluctuates considerably in solution, allowing for the insertion of homologous α subunits, finally converting to the hetero-heptameric α rings in the 20S proteasome.

PubMed: 33926037
DOI: 10.3390/ijms22094519

実験手法

ELECTRON MICROSCOPY (5.9 Å)