A working model of VDAC
regulation of ATP flux. A rectangular section of membrane containing 4
channels is illustrated both in oblique view (lower) and top view (upper).
The design of the channels embodies our current understanding of the structure
of VDAC and of its gating process. The membrane potential drives a portion
of the wall of the channel, that serves as a positively-charged voltage
sensor (colored blue), out of the channel during the closing process resulting
in a net negatively charged region (pink) within the pore. The swarm of
ATP molecules are illustrated as red ellipsoids. The relative sizes of
the pores and ATP are about to scale.