(a)
Ab initio small-angle X-ray scattering (SAXS) reconstruction, experimental scattering curves, normalized pair distance distribution function, P(r) and Kratky plot showing the degree of flexibility of (a) WT Izumo122-254-E45K Juno20-228, (b) WT Izumo122-254-K163E Juno20-228, (c) E71K Izumo122-254-WT Juno20-228, and (d) R160E Izumo122-254-WT Juno20-228 complexes. No concentration-dependent or radiation effects were observed. The inset box shows linearity in the Guinier plot at low q (qRg <1.3). The WT Izumo122-254-WT Juno20-228 complex crystal structure was docked into the SAXS reconstructed molecular envelopes. (e) Summary of the experimentally derived SAXS parameters for the various Izumo1-Juno complexes. The program SCATTER47 was used to calculate the radius of gyration (Rg), maximum linear dimension (Dmax), and to perform Porod-Debye analysis to obtain the Porod volume and P coefficient.