Collagens are fibrous, extracellular matrix proteins with high tensile strength and are the major components of connective tissue, such as tendons and cartilage. All collagens contain a triple helix domain and frequently show lateral self-association in order to form complex connective tissues. Several collagens also play a role in cell adhesion, important for maintaining normal tissue architecture and function. COL5A3 (collagen (alpha)-3(V) chain) is a 1,745 amino acid extracellular matrix protein that belongs to the fibrillar collagen family and acts as a minor connective tissue. COL5A3 contains one TSP N-terminal (TSPN) domain, a fibrillar collagen NC1 domain.