Kinesin moving along a microtubule. (1) One head of a two-headed kinesin molecule, initially with both heads in the ADP form, binds to a microtubule. (2) The release of ADP and the binding of ATP results in a conformational change that locks the head to the microtubule and pulls the neck linker (orange) to the head domain, throwing the second domain toward the plus end of the microtubule. (3) ATP undergoes hydrolysis while the second head interacts with the microtubule. (4) The exchange of ATP for ADP in the second head pulls the first head off the microtubule, releasing Pi and moving the first domain along the microtubule. (5) The cycle repeats, moving the kinesin dimer farther down the microtubule.