Essential dynamics of the loop model. (a) RMSD profiles for the intracellular part of TM6 in the loop model’s original trajectory and after the projection onto the first and the cumulative five principal modes. (b) Original and reconstructed profiles for the distance between Ser207(Cα) and Asp113(Cα). (c) The correlation plot between RMSD of TM6 and Ser207-Asp113 distance. (d) Projection of the loop model’s trajectory onto the first principal mode, shown as harmonic motion.