Figure 11.

The position of non-identical amino acids between human and mouse CD81 and CD9 projected onto the model of CD9/CD81 complex (Figure 9C). The differences in amino acid sequence are depicted as red spheres. The CD81 moiety (yellow) contains 17 differences in the extracellular domain, while the CD9 (shades of blue) differs in 25 amino acids located also at the CD9/CD81 interface. These differences could be responsible for species specific interaction between CD9 and CD81 as well as recognition by other proteins.