Comparing the actomyosin interface of the rigor and ADP-bound forms. (A) Model of the actin, tropomyosin, and myosin complexes. The ADP-bound form (gold) and rigor form (orcid) are overlaid in order to show the similarities of the models at the actomyosin interface. The regions of the actomyosin interface are boxed. (B) Regions of the actomyosin interface indicated from A are enlarged. The interacting residues from the CM loop, loop 4, and the helix-loop-helix motif in both myosin models are shown overlaid. It is clear from these comparisons that the interface is conserved despite the nucleotide bound to the active site.