a microtubule without becoming completely detached.

In the apo-state of dynein, the motor is nucleotide free, the AAA domain ring exists in an open conformation, and the MTBD exists in a high affinity state. Much about the AAA domains remains unknown, but AAA1 is well established as the primary site of ATP hydrolysis in dynein. When ATP binds to AAA1, it initiates a conformational change of the AAA domain ring into the "closed" configuration, movement of the buttress, and a conformational change in the linker.