['Kar3Vik1 is a heterodimeric kinesin with one catalytic subunit (Kar3) and one noncatalytic subunit (Vik1).', 'Vik1 experiences conformational changes in regions analogous to the force-producing elements in catalytic kinesins.'] Do neck rotation and neck mimic docking in the noncatalytic Kar3-associated protein Vik1?