Extended Data Fig. 9: Crystal structure of b11L5F_LGL, mFAP0 and mFAP1.

a-g, b11L5F_LGL crystal structure. (Protein samples of all six triple mutants in Extended Data Fig. 8b(right) were prepared for crystallization. b11L5F_LGL with V83L/V95G/V103L combination was successfully crystallized). Crystal contacts between protein copies in one asymmetric unit (yellow) were mediated by two tyrosines (stick representation, grey dashed circle); contacts between three asymmetric units (yellow, blue and green) were formed between β-turns (black dashed circle), which might have displaced one of the top β-turns (c). Overall backbone and side chain conformations in the design model matched the crystal structure with a backbone Cα RMSD of 1.02Å (b, crystal in yellow and design model in silver), and the designed disulfide bond was present in the crystal structure (d). Ligand density in the crystal structure was ambiguous: 2Fo − Fc omit map showing the electron density after refinement without placing DFHBI (e), the best ligand placement to match the density (f), and designed ligand binding interactions (silver) overlaid with the crystallized binding pocket (g). h&i, Crystal contacts in the DFHBI-bound structures of mFAP0(h) and mFAP1(i). Contacts between proteins copies in one asymmetric unit were formed around 40V and 54Y (grey dashed circle) that were introduced for helping crystallization (Extended Data Fig. 10a). Contacts between asymmetric units were formed between β-turns (black dashed circle). j, 2Fo−Fc omit electron density of DFHBI in the mFAP0-DFHBI complex crystal structure. DFHBI density contoured at 1.0σ is clear and matches the planar conformation of the ligand (right). k, Superposition of mFAP0 design model (silver) and the crystal structure (magenta). Hydrogen bonds were indicated with dashed lines. e, Helical capping interactions mediated by P62D mutation in mFAP1 crystal structure.