Fig. 1: Structure of human cardiac thin filament in the Ca2+ free state.
From: Cardiac muscle thin filament structures reveal calcium regulatory mechanism
a a typical cryoEM image of the thin filament with periodic Tn binding along actin filament. b The model of the thin filament fitted into the cryoEM density map in two different views. Approximately 12 actin subunits are shown with a pair of Tm coiled coils and a pair of the Tn ternary complexes consisting of the Tn core, TnIC extended upward from the core and TnTN attached closely to the head–tail junction of Tm near the bottom. c Magnified images of TnTN complexed with the head–tail junction of Tm. The models are colored as: actin, beige; Tn, purple; and Tm, light blue and orange. Actin filament is oriented with its pointed end top including all the other figures.
