Physics (Internal)

Mechanical Design of the Kinesin Motor

This event is part of the Biophysics/Condensed Matter Seminar Series.

Abstract:
A longstanding question about conventional kinesin, the smallest bipedal motor protein known to date, is the mechanochemical amplifier: How it converts the chemical energy associated with adenosine triphosphate (ATP) into mechanical work. Using molecular dynamics simulations and structural analyses, we found that force is generated by a dynamic folding transition of a mechanical element. Binding of an ATP molecule on the motor head attached to the microtubule track, triggers folding of a beta-sheet domain named the cover-neck bundle. The cover-neck bundle possesses a conformational bias necessary to propel the other stepping head forward. Single-molecule motility measurements on mutant kinesins designed to possess altered force-generating capacities support the cover-neck bundle mechanism. Identification of the dynamic force-generating element makes it possible to control motility of kinesin, which is a major intracellular cargo carrier as well as a rising target for pharmaceutical and biotechnological applications.