You are studying myosin V, a class of myosin which can be usedin cells to transport vesicles by “walking†along actin filaments,towards the plus ends of these filaments. You have identified amutation in the gene for myosin V that affects its ATP bindingsite. This mutant myosin V (M) can still perform the entirecross-bridge cycle, but it takes much longer to hydrolyze ATPcompared to a wild type myosin V (W).
a) Would the duration of the cross-bridge cycle be longer in Mor W?Explain?
b) Would the duty cycle (the proportion of the cross-bridgecycle in which myosin is bound to actin) be longer in M orW?Explain?
c) How would this difference in duty cycle affect the ability ofM to transport a vesicle along an actin filament? Explain.
