English: This is a movie created in Chimera using the Ci-VSP PDB structures 3V0D, 3V0F, 4G7V, and 4G80. The catalytic domain structures (pink) were reported by Liu et al. in 2011, and the voltage sensing domain structures (blue) were reported by Li et al. in 2014. Since both the voltage sensor and the catalytic domain have crystal structures in the "up/open/on" and the "down/closed/off" states, we can generate a morph between the two states to see what movement of VSPs might look like in cells. The red residues show the arginines, important for sensing voltage across the cell membrane. The blue residue shows a glutamate, proposed to act as a "switch" that regulates access to the catalytic cysteine (shown in orange). The region bridging the voltage sensor and the catalytic domain is not well-resolved. For this video, a part of that linker region was modeled using the CPHmodels 3.2 server (shown in grey).