Fig. 1.

SAXS rigid body modeling of free C1r₂s₂ tetramer assuming a central C1r dimer. (A) Schematic representation of the starting model for rigid body refinement with the imposed distance restraints indicated by a double-headed arrow. (B) Atomic start model. Visible collagen sites in C1r CUB1 and CUB2 and C1s CUB1 are marked with green circles. (C) Representative optimal output model after rigid body refinement with CORALXL. (D) Comparison of the scattering curve calculated from the model in C with the experimental curve. (E) Comparison of weighted residual plots for our original C1r₂s₂ output model (2) based on CUB1–EGF interactions and the C1r₂s₂ model based on C1r CCP1-SP contacts presented in C suggests similar resolution dependency for the fit between the experimental and model data for the two different output models.