The troponin (Tn) complex is formed by TnC, TnI and TnT and is respon-sible for the calcium-dependent inhibition of muscle contraction. TnC and TnI interact in an antiparallel fashion in which the N domain of TnC binds in a calcium-dependent manner to the C domain of TnI, releasing the inhibitory effect of the latter on the actomyosin interaction. While the crys-tal structure of the core cardiac muscle troponin complex has been deter-mined, very little high resolution information is available regarding the skeletal muscle TnI–TnC complex. .
