Structures of kinesin and kinesin–microtubule interactions

Several X-ray crystal structures of kinesin motor domains have recently been solved at high resolution (∼0.2–0.3 nm), in both their monomeric and dimeric states. They show the folding of the polypeptide chain and different arrangements of subunits in the dimer. In addition, cryo-electron microscopy and image reconstruction have revealed microtubules decorated with kinesin at intermediate resolution (∼2 nm), showing the distribution and orientation of kinesin heads on the microtubule surface. The comparison of the X-ray and electron microscopy results yields a model of how monomeric motor domains bind to the microtubule but the binding of dimeric motors, their stoichiometry, or the influence of nucleotides remains a matter of debate