A protein, found in many eukaryotic cells, that possesses ATPase activity and binds to microtubules. Dynein is associated with the microtubules of cilia and flagella; it moves along the microtubules, using energy derived from the hydrolysis of ATP, causing the cilium or flagellum to bend. Dynein in the cytoplasm of cells causes the movement of organelles along the microtubules.