Figure 2
Ternary ligand-receptor complex of BMP-2 variant L100K/N102D. Ribbon representation (stereoview) of the ternary complex of the BMP-2 double variant L100K/N102D (in yellow and blue) bound to BMPR-IAECD (green) and ActR-IIBECD (red), viewed from the side (a) or from above (b). (c) Distances between the C-termini of the receptor ectodomains of each subtype are indicated. (d) The shortest distance between BMPR-IAECD and ActR-IIBECD occurs between the two receptor ectodomains located on the same half of the BMP-2 dimer across the β-sheet of BMP-2 and measures ~12 Å. No direct receptor-receptor contacts between the ectodomains of either subtype as proposed for the TGF-β:TGF-β receptor interaction [44, 47, 61] can be observed.