Fig. 3: Identification of capsid mutations that impede FG phase partitioning.
From: Nuclear pore passage of the HIV capsid is driven by its unusual surface amino acid composition
Partitioning experiments into the FG phase (GLFG 12-mer repeats) were performed as in Fig. 1c but using indicated (wild-type or mutant) CLPs noncovalently filled with sinGFP4a. Experiments were independently replicated three times, yielding consistent outcomes. Scale bars, 10 μm. Negative-stain electron micrographs, validating proper capsid assembly, are shown in Extended Data Fig. 4. a, Comparison of wild-type CLPs and CLPs carrying previously reported mutations. Note the strong FG phase-partitioning defect of the N57A, A92E and G94D mutant CLPs. b, Illustration of the observed FG phase-partitioning phenotypes. c, Illustration of the quantification strategy. Fluorescence signals for the capsid species were integrated separately at the rim and in the center of FG particles, normalized to the wild-type values, and listed for each mutant in a,d,e (more detailed quantifications in Extended Data Fig. 5). d, Drastic FG-partitioning defects in rationally designed capsid mutants, where FG-attractive residues were exchanged for FG-repulsive ones (glutamic acid or lysine). e, Selected CA positions were mutated to G, Q or E, as indicated. Drastic FG phase-partitioning defects were evident only when an FG-repulsive glutamic acid was introduced. Mutations to an FG-neutral glycine or glutamine had mild effects at best. f, A CA hexamer (PDB 4WYM) viewed from the side and the capsid’s outside. Surface mutant positions with FG-partitioning defects are colored in green and the N57 FG-binding pocket is colored in cyan.
