Jose Onuchic gives a talk at the RPP08 conference on the mechanics of molecular motors. The discussion includes:
1) The reflection of constraints of the molecular architecture the dynamical pathways during stepping
2) The role of rectified diffusional motion.

For the last 7 years I have been driving an environmentally responsible car called the "Gizmo". In terms of performance with respect to fossil fuels, it gets the equivalent of 150 miles per gallon!