Figure 2.

Crystal structure of RABV N_∆23⁰−P₆₈ core complex. (A) Schematic representation of RABV nucleoprotein modular organization and construct. The upper part shows the structural organization of the nucleoprotein. Boxes indicate the localization of folded domains, dotted boxes the localization of the exchanging subdomains N_NT-ARM and N_CT-ARM. The lower part shows the construct of the nucleoprotein used in this study. (B) SEC MALLS of the reconstituted complex. The elution was monitored on-line using multi-angle laser light scattering and differential refractometry. The line shows the chromatograms monitored by differential refractive index measurements. The red crosses indicate the molecular mass across the elution peak calculated from static light scattering and the numbers indicate the weight-averaged molecular mass (kDa) with standard deviations. Theoretical mass of the heterodimer = 48,208.5 Da (N_Δ23) + 8488.4 Da (P₆₈) = 56,696.9 Da. (C) Crystal structure of RABV N_∆23⁰−P₆₈ core complex (8b8v.pdb) in cartoon representation. N_∆23⁰ is shown in blue and P₆₈ in red. The dotted line in P₆₈ shows the position of the four residue loop that is less-well defined in the electron density map, while the dotted lines in N show the position of the missing loops in N_NTD and the N_CT-ARM. The N- and C-terminal residues of P₆₈ are indicated. (D) Conservation of the N⁰−P interface. View of the region of interaction of residues 4 to 15 of P_CM. The complex is shown with surface and conservation representations for N_∆23 and with stick-and-ball representations for P₆₈. The conservation in N derived from multiple sequence alignment is displayed on the surface of NiV N: blue low-level conservation, <20%; maroon, high-level conservation, >80%. The side chains of conserved residues in the P N-terminal region are shown in stick representation. (E) Conservation of the N⁰−P interface. View of the region of interaction of residues from 20 to 39 of P_CM with same color scheme and representation as in panel (D). (F) Superposition of RABV N⁰−P and N−RNA structures. The structures were superposed by aligning the C-terminal domains of both structures. (G) Out-of-register construction in N_NTD. Close-up view of a small region of N_NTD illustrating the change of register of residues from 27 to 130 between the original circular N₁₁−RNA structure (2GTT.pdb) shown in yellow and the N_∆23⁰−P₆₈ structure (8B8V.pdb) shown in blue. (H) Interference of P_CM binding with N_NT-ARM and N_CT-ARM binding. Close-up view of the interference between P_CM (in red) and the N_NT-ARM from the N_i-1 subunit (in olive) and N_CT-ARM of the Ni+1 subunit (in green). (I) Interference of P_CM binding with RNA binding. Close-up view of the interference between P_CM in (red) and RNA (in orange). (J) Superposition of RABV N_∆23⁰−P₆₈ and VSV N_Δ21⁰−P₆₀ complex.