FIGURE 7.

Structure-based interaction sequence matrix illustrating specificity determining residues for RhoA interaction with its GEFs. Based on the crystal structures of RhoA (G domain) in the complex with DH-PH of PRG (16) (Protein Data Bank code 1XCG) and of LARG (17) (Protein Data Bank code 1X86) the interacting residues (colored background; <4 Å in distance) were determined and aligned onto the DH-PH tandem and the G domain of RhoGTPases. Residues with a light blue background are conserved in Rho-specific GEFs and critical in determining the specificity of the RhoA/DH-PH interaction. Variable residues with a black background may be critical in determining the catalytic efficiency of Rho-specific GEFs.