Figure 6.

Crystal structure of a chimeric rabbit/human Fab selected by phage display in complex with HIV-1 Rev (PDB accession code 2X7L).^{98, 99} The three CDR loops of the heavy chain are colored blue and the three CDR loops of the light chain are colored orange. Amino-acid residue side chains that interact with the antigen (gray) are drawn as sticks. Note the dominating contribution of LCDR3 to the paratope. When synthesized as cyclic peptide, LCDR3 on its own was able to bind HIV-1 Rev with high affinity.¹⁶²