Localization of TRIM22-sensitive lysine residues in the NP molecular structure. Shown is a structural model of the mutant form of NP resistant to TRIM22 restriction. (A) The model of NPR4/K4, an NP with 4 R-to-K single-point mutations (R98K, R293K, R422K, and R446K), was generated using PDB code 2IQH as the template (18). NP is represented as cartoons, with the head and the body of the protein colored in pink and cyan, respectively. K98, K293, K422, and K446 are highlighted as sticks and numbered with the single-letter code. (B) The interactions predicted for K98 (left), K293 (middle), and K422 and K446 (right) are shown. Residues are highlighted as sticks and numbered with the single-letter code. (C) The model of NPR4/K4 in a helical ribonucleoprotein-like structure using PDB code 4BBL as the template (21) is shown as the surface. Images were prepared using pymol-v1.8.4.2 (PyMOL Molecular Graphics System, version 1.8; Schrödinger, LLC) and the Maestro software package (42).