A Point Mutation of Integrin/3 Subunit Blocks Binding of Otsi3 to Fibronectin and Invasin but not Recruitment to Adhesion Plaques

A point mutation in a highly conserved re- gion of the/3~ subunit, Asp ~3~ to Ala (D130A) substitu- tion, abrogates the Arg-Gly-Asp (RGD)-dependent bind- ing of ot5/3~ to fibronectin (FN) without disrupting gross structure or heterodimer assembly. The D130A muta- tion also interferes with binding to invasin, a ligand that lacks RGD sequence. In spite of the lack of detec-