9FJO

Structure of the undecorated pointed end of F-actin

9FJO の概要

• エントリーDOI: 10.2210/pdb9fjo/pdb
• 関連するPDBエントリー: 9FJM
• EMDBエントリー: 50507
• 分子名称: Actin, alpha skeletal muscle, ADENOSINE-5'-DIPHOSPHATE, MAGNESIUM ION (3 entities in total)
• 機能のキーワード: actin, filament, pointed end, structural protein
• 由来する生物種: Oryctolagus cuniculus (rabbit)
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 169308.56

構造登録者

Boiero Sanders, M.,Oosterheert, W.,Hofnagel, O.,Bieling, P.,Raunser, S. (登録日: 2024-05-31, 公開日: 2024-09-11, 最終更新日: 2024-10-02)

主引用文献

Boiero Sanders, M.,Oosterheert, W.,Hofnagel, O.,Bieling, P.,Raunser, S.
Phalloidin and DNase I-bound F-actin pointed end structures reveal principles of filament stabilization and disassembly.
Nat Commun, 15:7969-7969, 2024

PubMed Abstract: Actin filament turnover involves subunits binding to and dissociating from the filament ends, with the pointed end being the primary site of filament disassembly. Several molecules modulate filament turnover, but the underlying mechanisms remain incompletely understood. Here, we present three cryo-EM structures of the F-actin pointed end in the presence and absence of phalloidin or DNase I. The two terminal subunits at the undecorated pointed end adopt a twisted conformation. Phalloidin can still bind and bridge these subunits, inducing a conformational shift to a flattened, F-actin-like state. This explains how phalloidin prevents depolymerization at the pointed end. Interestingly, two DNase I molecules simultaneously bind to the phalloidin-stabilized pointed end. In the absence of phalloidin, DNase I binding would disrupt the terminal actin subunit packing, resulting in filament disassembly. Our findings uncover molecular principles of pointed end regulation and provide structural insights into the kinetic asymmetry between the actin filament ends.

PubMed: 39261469
DOI: 10.1038/s41467-024-52251-3

実験手法

ELECTRON MICROSCOPY (3.05 Å)