Tropomyosin

Tropomyosin is a two-stranded alpha-helical, coiled coil protein found in many animal and fungal cells. In animals, it is an important component of the muscular system which works in conjunction with troponin to regulate muscle contraction. It is present in smooth and striated muscle tissues, which can be found in various organs and body systems, including the heart, blood vessels, respiratory system, and digestive system. In fungi, tropomyosin is found in cell walls and helps maintain the structural integrity of cells.

Tropomyosin is also found in other eukaryotes, but not in plants. Overall, tropomyosin is an important protein that plays a vital role in the proper functioning of many different organisms.