Troponin Revealed: Uncovering the Structure of the Thin Filament On-Off Switch in Striated Muscle.

ABSTRACT: Recently, our understanding of the structural basis of troponin-tropomyosin's Ca²⁺-triggered regulation of striated muscle contraction has advanced greatly, particularly via cryo-electron microscopy data. Compelling atomic models of troponin-tropomyosin-actin were published for both apo- and Ca²⁺-saturated states of the cardiac thin filament. Subsequent electron microscopy and computational analyses have supported and further elaborated the findings. Per cryo-electron microscopy, each troponin is highly extended and contacts both tropomyosin strands, which lie on opposite sides of the actin filament. In the apo-state characteristic of relaxed muscle, troponin and tropomyosin hinder strong myosin-actin binding in several different ways, apparently barricading the actin

SUBMITTER: Tobacman LS 

PROVIDER: S-EPMC7820733 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature