Tropomyosin, in association with the troponin complex, plays a central role in the calcium dependent regulation of muscle contraction. Involved in muscle actin filament organization and muscle arm extension and morphology. Also has a role in male mating behavior by regulating the copulatory spicules. Binds to F-actin (By similarity). The molecule is in a coiled coil structure that is formed by 2 polypeptide chains. The sequence exhibits a prominent seven-residues periodicity. Belongs to the tropomyosin family.