There are many ubiquitous proteins that can be found in many organisms throughout nature. Actin and myosin are proteins that make contraction, and therefore movement possible.
Most organisms depend on movement in their quest to survive.
It is logical, therefore, that most organisms' genomes contain genes that code for actin and myosin. Collagen is a vital protein as it serves as a indispensable constituent of connective tissue. Collagen acts to link structures and hold them together. It is found in the basal lamina, in bones, in tendons, and in various other locations. Additionally, a three dimensional look at collagen is provided.