Extended Data Fig. 7: Binding of PF74 to CA hexamer and its effects on CA tubular assembly.
a, Light scattering of CA assemblies in the presence of PF74 at the indicated concentrations. b, Average number of tubes in each EM micrograph taken at the same magnification, with representatives shown in d–f. c, Distribution of the length of tubular assemblies in the presence of 0 µM (black), 10 µM (green) and 50 µM (pink) PF74. d–f, Representative images of negatively stained CA assemblies in the presence of 0 µM (d), 10 µM (e) and 50 µM (f) PF74. Scale bars, 0.5 µm. g, Atomic model of CA hexamer, clipped to show CANTD. Each CA monomer is labeled. The vertical dashed line indicates the tube axis. h–j, Overlay of density map with atomic model, showing the position of Arg173, which is critical for the binding of PF74 to hexamer57. Three CANTD-CACTD interfaces within the CA hexamer are shown between chains A-F (h), chains B-A (i) and chains C-B (j). Intermolecular hydrogen bonds between CACTD and CANTD are marked by red dashed lines with corresponding distances indicated. k, Overlay of WT and PF74-bound CA crystal structures, colored in grey and cyan, respectively. l, Overlay of three different PF74 pockets from the asymmetric hexamer in (-13,8) helical symmetry with crystal structures (PDB 4XFX and PDB 4XFZ). Arg173 side chains are shown in gold, red and blue, corresponding to panels h–j. The chain C-B interface is more similar to the crystal structure than are the chain A-F and chain B-A interfaces.
