Figure 1. CFH–CCP20 is responsible for SdrE_N2N3 binding.

(A) Schematic representation of SdrE and CFH domain organization. S, signal sequence; N1–N3, ligand-binding region; B1–B3, B repeats region; R, serine–aspartate repeat region; W, wall-spanning region; M, membrane-spanning region; C, cytoplasmic, positively charged tail. The amino acid residue number identifying the boundary between each subdomain is indicated above. (B–D) GST pull-down assays of SdrE_N2N3 with different fragments of the CFH fused to a GST tag. The retaining amino acid residues of each CFH fragment are indicated in each panel. (E) The ITC fitting curves of GST–CFH^1206–1226 to SdrE_N2N3.