Figure 1
From: Structural basis for the inhibition of HIV-1 Nef by a high-affinity binding single-domain antibody
Structure of the tripartite SH3 B6 –Nef–sdAb19 complex. (A) Size exclusion chromatography of Nef supplemented with sdAb19 and SH3B6 reveals the equimolar hetero-trimeric association of the three subunits. (B) ITC measurement of SH3B6 binding to NefSF2. (C) Binding of the camelid antibody sdAb19 to HIV-1 Nef showed a dissociation constant of 39 nM. (D) Crystal structure of HIV-1 NefSF2 (beige) in complex with camelid sdAb19 (green) and the SH3 domain of Hck (light blue). The two Nef interacting proteins bind to opposite surfaces of Nef. The position of the C-terminal flexible loop in Nef is indicated. Cysteines C24 and C97 in the canonical fold of sdAb19 are reduced in the crystal structure as shown in the final 2F o –F c electron density map displayed at 1 σ (inset). The PDB accession number of the tripartite sdAb19 complex is 4ORZ.