Description
The Fibronectin type III domain is an evolutionary conserved protein domain that is widely found in animal proteins. The fibronectin protein in which this domain was first identified contains 16 copies of this domain. The domain is about 100 amino acids long and possesses a beta sandwich structure. Of the three fibronectin-type domains, type III is the only one without disulfide bonding present. Fibronectin domains are found in a wide variety of extracellular proteins. They are widely distributed in animal species, but also found sporadically in yeast, plant and bacterial proteins