We used SAXS to assess the effects of P3 on the full-length MERS-CoV N protein structure. The fitted distance distribution function of the protein with and without P3 are shown in Figure 3A. P3 increased the maximum dimension (Dmax) and radius of gyration (Rg) of the protein from 207 to 230 Å and from 58 to 65 Å, respectively. Thus, the size of the MERS-CoV N protein in solution was altered upon binding to P3.