(a) All interface amino acids labeled on an open-book view of the Dpr–DIP interface, based on the Dpr1-DIP-η structure. Core side chains, defined in Figure 3c1–3 are yellow, and the periphery side chains are The three hydrogen bonding side chains in Dpr1–DIP-η complex, are all in the periphery and are marked within black, purple and light green circles. One salt bridge is also labeled. (b) When only the amino acids at the interface of Dprs are aligned, their cognate DIPs are displaced from each other, most significantly for Dpr11-bound DIP-γ. This is most significant in the image above, where DIP-γ pivots away from the interface. At the orthogonal view (below), the displacement of DIP-γ is not noticeable. (c,d) 2mFo–DFc electron density maps from phenix.refine show that rotamers at the interface are well defined by electron density. Maps are contoured at 1.4 σ. Equivalent amino acids Dpr1 I88 (c) and Dpr6 I108 (d) are in different rotameric states, supported by electron density. .