Figure 2: CryoEM reconstruction of CypA /CA tubular assemblies.
From: Cyclophilin A stabilizes the HIV-1 capsid through a novel non-canonical binding site
(a) CryoEM image of a CypA-CA tubular assembly at 2:6 CypA:CA input ratio. Inset, radial density profile from the boxed region showing the CypA density (black arrows) decorating the CA tubular assembly (red arrows). (b) Fourier transform of a CypA-CA tubular assembly. Arrow indicates a layer line at 13.8 Å resolution. (c) 3D density map of the CypA-CA assembly complex reconstructed at 8 Å resolution (see Supplementary Fig. 1). The density (contoured at 2σ) is coloured radially from yellow-green (CA) to blue (CypA). CypA selectively binds to the CA array that has the highest curvature. (d) Rigid body docking of CA hexamers (3J4F, green ribbon) into the CA region of the density map (yellow density), viewed from the side and top. The area shown is from the boxed region in C. (e) Aligning the CypA-CA complex (PDB: 1AK4) to the docked CA hexamer model, overlaid with the density maps contoured at 2σ (yellow) and at 1.5σ (blue). The CypA molecule (blue ribbon) is situated right at the bridging density, across two CA hexamers (green ribbons) and above the CA dimer interface (arrow).
