Movie S2.

Dynamics in the interface between cd1NiR and cNOR in the MD simulation of trajectory 1. Video illustrates side-chain fluctuations and transient hydrogen bonds at the interface of cd1NiR and cNOR. cd1NiR and cNOR are shown with blue and red, respectively. The residues which frequently form hydrogen bonds (including salt bridge) are shown by sticks. Hydrogen bonds are represented by dashed lines. Several typical snapshot of this simulation are presented in SI Appendix, Fig. S5.