Collective motion analysis. (A) and (B) represent the percentage of cumulative eigenvalues as a function of eigenvector indices for the homodimers and heterodimers, respectively. (C) and (D) represent the porcupine plot of the first eigenvector of the homodimer and heterodimer, respectively. The basic domain is colored in orange for the TWIST1 monomers and in yellow for the E47 monomer. The cones point in the direction of indication mode of atomic movement, and the amplitude of the motion is represented by the length of the cone.