This gene encodes an alpha chain for one of the low abundance fibrillar collagens. Fibrillar collagen molecules are trimers that can be composed of one or more types of alpha chains. Type V collagen is found in tissues containing type I collagen and appears to regulate the assembly of heterotypic fibers composed of both type I and type V collagen. This gene product is closely related to type XI collagen and it is possible that the collagen chains of types V and XI constitute a single collagen type with tissue-specific chain combinations. The encoded procollagen protein occurs commonly as the heterotrimer pro-alpha1(V)-pro-alpha1(V)-pro-alpha2(V). Mutations in this gene are associated with Ehlers-Danlos syndrome, types I and II. Alternative splicing of this gene results in multiple transcript variants. [provided by RefSeq, May 2013],disease:Defects in COL5A1 are a cause of Ehlers-Danlos syndrome type 1 (EDS1) [MIM:130000]; also known as Ehlers-Danlos syndrome gravis or severe classic type Ehlers-Danlos syndrome. EDS is a connective tissue disorder characterized by hyperextensible skin, atrophic cutaneous scars due to tissue fragility and joint hyperlaxity. EDS1 is the severe form of classic Ehlers-Danlos syndrome.,disease:Defects in COL5A1 are a cause of Ehlers-Danlos syndrome type 2 (EDS2) [MIM:130010]; also known as Ehlers-Danlos syndrome mitis or mild classic type Ehlers Danlos syndrome.,function:Type V collagen is a member of group I collagen (fibrillar forming collagen). It is a minor connective tissue component of nearly ubiquitous distribution. Type V collagen binds to DNA, heparan sulfate, thrombospondin, heparin, and insulin.,PTM:Prolines at the third position of the tripeptide repeating unit (G-X-Y) are hydroxylated in some or all of the chains.,PTM:Sulfated on 40% of tyrosines.,similarity:Belongs to the fibrillar collagen family.,similarity:Contains 1 laminin G-like domain.,similarity:Contains 1 TSP N-terminal (TSPN) domain.,subunit:Trimers of two alpha 1(V) and one alpha 2(V) chains in most tissues and trimers of one alpha 1(V), one alpha 2(V), and one alpha 3(V) chains in placenta. Interacts with CSPG4.,