SAXS analysis. (A) SAXS scattering pattern (black) and fitted scattering pattern calculated from best-fitting two-state model (red). ‘Dimer’ and ‘monomer’ refer to the corresponding peaks of the SEC-SAXS experiment (see Supplementary Fig. 1C,D). (B) Table showing SAXS-derived radius of gyration (Rg), maximum diameter (Dm), calculated and SAXS-derived molecular weight (Mw), and the fitting parameters (𝛘2) for the single-state (1-state) and two-state (2-state) models. Best-fitting models were selected from a pool of models containing five representatives of each, closed maltose-bound interlaced MBP-fusion dimers (Dc), open ligand-free dimers (Do), closed monomers (Mc) and open monomers (Mo). For each type of model, the five representatives differ by the positioning of the KFLFAK or KFLPYK2 sequence. The type of selected best scoring model is indicated. For the 2-state models, the relative contribution of each individual model is given as % value. Figures were prepared using GraphPad Prism 6.0 (https://graphpad.com).