Five-dimensional collective
variable (CV) space used to optimize
the minimum free energy path identified in a data-driven manner. (a)
A fully connected neural network was trained to classify configurations
in active, intermediate, and inactive metastable states (clusters).
Deep Taylor decomposition was then used to identify the most important
input inter-residue distances for the classification decision. The
top-ranked distances were used as CVs. (b) The five CVs used in this
work projected onto an intracellular view of the active crystal structure
(PDB entry 3P0G). The CVs corresponding to TM2–TM7, TM6–TM4, TM7–TM4,
TM3–TM6, and TM6–TM5 distances defined in Table S2 are shown as purple, blue, green, yellow,
and red dashed lines, respectively. The change of these distance CVs
from the inactive to the active state structures is reported in nanometers.