Figure 1

Crystal structure of the hPRL-R in complex with sAB A8. a sAB A8 (green) binds to the human PRL-R (red) opposite to the hormone binding site. b A close up of the interactions between the CDR loops of sAB A8 (green) and the hinge region between the two fibronectin (FN) domains of PRL-R (red). c Alignment of the FN2 domains of the PRL-R structure determined here (red) with the PRL-R structure (yellow) bound to PRL (grey) in the 2:1 complex (PDB code: 3NPZ), the side view (above) shows the twist between the two FN domains induced by sAB binding and the top view (below) shows a rotation of the FN1 domain relative to the FN2 domain in the sAB-bound structure. d Alignment of the sAB-bound PRL-R (red) with the hGH-bound PRL-R (green) and the PRL-bound PRL-R (yellow) using the FN2. The bottom panel is a top view of the FN1 of all three structures, with the sAB-bound receptor more resembling the hGH-bound conformation. e Inhibition of sAB binding by hGH or PRL using phage ELISA. Both hGH (left panel) and PRL (right panel) inhibit the interaction between phage-displayed sABs and hPRL-R in a concentration dependent manner. f IC₅₀ values of the hGH or PRL inhibition of the interaction between sABs and hPRL-R calculated from e.