Aurora B kinase disrupts the extended conformation of lattice-bound Kinesin-13 MCAK

We reveal that MCAK has a compact conformation in solution using cross-linking and electron microscopy. When MCAK is bound to the microtubule ends, it adopts an extended conformation with the N terminus and neck region of MCAK interacting with the microtubule. Also Aurora Bphosphorylation does not alter MCAK conformation in solution. Aurora B interferes with the extended conformation of MCAK on microtubules to decrease the affinity of MCAK for microtubules and reduces its depolymerase activity in a graded fashion.