7B19

Mutant Myosin-II-GGG motor domain

7B19 の概要

• エントリーDOI: 10.2210/pdb7b19/pdb
• 分子名称: Myosin-2 heavy chain,Myosin-2 heavy chain, ADP METAVANADATE, MAGNESIUM ION, ... (8 entities in total)
• 機能のキーワード: myosin, motor protein, mutation, w-helix, hydrolase
• 由来する生物種: Dictyostelium discoideum (Slime mold); 詳細
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 91990.17

構造登録者

Ewert, W.,Preller, M. (登録日: 2020-11-24, 公開日: 2021-01-13, 最終更新日: 2024-01-31)

主引用文献

Franz, P.,Ewert, W.,Preller, M.,Tsiavaliaris, G.
Unraveling a Force-Generating Allosteric Pathway of Actomyosin Communication Associated with ADP and P i Release.
Int J Mol Sci, 22:-, 2020

PubMed Abstract: The actomyosin system generates mechanical work with the execution of the power stroke, an ATP-driven, two-step rotational swing of the myosin-neck that occurs post ATP hydrolysis during the transition from weakly to strongly actin-bound myosin states concomitant with P release and prior to ADP dissociation. The activating role of actin on product release and force generation is well documented; however, the communication paths associated with weak-to-strong transitions are poorly characterized. With the aid of mutant analyses based on kinetic investigations and simulations, we identified the W-helix as an important hub coupling the structural changes of switch elements during ATP hydrolysis to temporally controlled interactions with actin that are passed to the central transducer and converter. Disturbing the W-helix/transducer pathway increased actin-activated ATP turnover and reduced motor performance as a consequence of prolonged duration of the strongly actin-attached states. Actin-triggered P release was accelerated, while ADP release considerably decelerated, both limiting maximum ATPase, thus transforming myosin-2 into a high-duty-ratio motor. This kinetic signature of the mutant allowed us to define the fractional occupancies of intermediate states during the ATPase cycle providing evidence that myosin populates a cleft-closure state of strong actin interaction during the weak-to-strong transition with bound hydrolysis products before accomplishing the power stroke.

PubMed: 33374308
DOI: 10.3390/ijms22010104

実験手法

X-RAY DIFFRACTION (2.55 Å)