A Small Unique Insert Found near the End of the Motor

Multiple Choice

A small unique insert found near the end of the motor domain in myosin VI has been linked to the singular ability of this myosin to move toward the pointed end of actin filaments. If the unique insert is removed by genetic engineering, the resulting mutant myosin VI is a plus-end directed motor. This observation indicates that …

A) the unique insert is necessary and sufficient for minus-end directionality.
B) the unique insert is necessary for motor activity.
C) the unique insert is necessary for plus-end directed directionality.
D) the unique insert is not sufficient for minus-end directionality.
E) None of the above.