Protein Domain : Fibronectin type III superfamily IPR036116

Type	Homologous_superfamily
Description	Fibronectin is a dimeric glycoprotein composed of disulfide-linked subunits with a molecular weight of 220-250kDa each. It is involved in cell adhesion,cell morphology, thrombosis, cell migration, and embryonic differentiation. Fibronectin is a modular protein composed of homologous repeats of three prototypical types of domains known as types I, II, and III [].Fibronectin type-III (FN3) repeats are both the largest and the most common of the fibronectin subdomains. Domains homologous to FN3 repeats have been foundin various animal protein families including other extracellular-matrix molecules, cell-surface receptors, enzymes, and muscle proteins []. Structures of individual FN3 domains have revealed a conserved β-sandwich fold with one β-sheet containing four strands and the other sheet containing three strands (see for example ) [ ]. This fold is topologically very similar to that of Ig-like domains, with a notable difference being the lack of a conserved disulfide bond in FN3 domains. Distinctive hydrophobic core packing and the lack of detectablesequence homology between immunoglobulin and FN3 domains suggest, however, that these domains are not evolutionarily related [].FN3 exhibits functional as well as structural modularity. Sites of interaction with other molecules have been mapped to short stretch of amino acids such as the Arg-Gly-Asp (RGD) sequence found in various FN3 domains. The RGD sequences is involved in interactions with integrin. Small peptides containing the RGD sequence can modulate a variety of cell adhesion invents associated with thrombosis, inflammation, and tumour metastasis. These properties have led to the investigation of RGD peptides and RGD peptide analogues as potential therapeutic agents [ ].
Short Name	FN3_sf