A motor protein is a protein that uses energy from thehydrolysis of high energy molecules called nucleotide triphosphates e.g. ATP. This energy is uded to move the protein along a linear track, for example a protein filament in the cytoskeleton .
Myosin is a motor protein associated with the actin filaments of the cytoskeleton or in muscle. The globular head of the myosin binds to ATP which is hydrolysed to produce the energy required for movement. There are two types of myosin, myosin I and myosin II, myosin I is found in all cells and only one head moves cargo down actin, on the other hand myosin II is found in muscle cells and two globular heads are present .
Kinesin is a motor protein associated with the microtubules of the cytoskelton, similarly to myosin they also have a head and a tail region, the head binds to the microtubule and ATP and the tail binds to the cargo for transport .
Dyneins are motor proteins that drive the movement of the cilia and flagella. Dyneins can cause filaments to slide past each other causing a beating movement, as in cilia, or they can cause the filaments to bend as in the flagella .
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