<p> Fibronectin is composed of three repeating structural motifs, of which one is the fibronectin III (FnIII) module. The three modules form a linear sequence of multiple tandem copies connected by short linker peptides. The secondary structure of the FnIII10 module, which is the only fibronectin module to possess an integrin binding RGD motif, consists of two beta-sheets containing the antiparallel beta-strands ABE and DCFG, respectively, which fold up to form a beta-sandwich. The RGD sequence is located in the loop connecting the beta-strands [<cite idref="PUB00010638"/>].</p> Fibronectin type III domain