A structural change in the kinesin motor protein that drives motility

Kinesin motors power many motile processes by converting ATP energy into un idirectional motion along microtubules, The force-generating and enzymatic properties of conventional kinesin have been extensively studied; however, the structural basis of movement is unknown. Here we have detected and visu alized a large conformational change of a similar to 15-amino-acid region ( the neck linker) in kinesin using electron paramagnetic resonance, fluoresc ence resonance energy transfer, pre-steady state kinetics and cryo-electron microscopy, This region becomes immobilized and extended towards the micro tubule 'plus' end when kinesin binds microtubules and ATP, and reverts to a more mobile conformation when gamma-phosphate is released after nucleotide hydrolysis, This conformational change explains both the direction of kine sin motion and processive movement by the kinesin dimer.