Mature HIV-1 capsid structure by cryo-electron microscopy and all-atom molecular dynamics.Zhao, G., Perilla, J.R., Yufenyuy, E.L., Meng, X., Chen, B., Ning, J., Ahn, J., Gronenborn, A.M., Schulten, K., Aiken, C., Zhang, P.
(2013) Nature 497: 643-646
- PubMed: 23719463
- DOI: 10.1038/nature12162
- Primary Citation of Related Structures:  3J3Y, 3J3Q, 3J34, 1VVI, 1VVH, 1VVG, 1VVF, 1VVB, 1VVA, 1VV9, 1VV8, 1VV7, 1VV6, 1VV5, 1VV4, 1VV3, 1VV2, 1VV1, 1VV0, 1VUZ, 1VUY, 1VUX, 1VUW, 1VUV, 1VUU, 1VUT, 1VUS, 1VUR, 1VUQ, 1VUP, 1VUO, 1VUN, 1VUM, 1VUL, 1VUK, 1VUJ, 1VUI, 1VUH, 1VUG, 1VUF,
- PubMed Abstract:
Retroviral capsid proteins are conserved structurally but assemble into different morphologies. The mature human immunodeficiency virus-1 (HIV-1) capsid is best described by a 'fullerene cone' model, in which hexamers of the capsid protein are linked ...
Retroviral capsid proteins are conserved structurally but assemble into different morphologies. The mature human immunodeficiency virus-1 (HIV-1) capsid is best described by a 'fullerene cone' model, in which hexamers of the capsid protein are linked to form a hexagonal surface lattice that is closed by incorporating 12 capsid-protein pentamers. HIV-1 capsid protein contains an amino-terminal domain (NTD) comprising seven α-helices and a β-hairpin, a carboxy-terminal domain (CTD) comprising four α-helices, and a flexible linker with a 310-helix connecting the two structural domains. Structures of the capsid-protein assembly units have been determined by X-ray crystallography; however, structural information regarding the assembled capsid and the contacts between the assembly units is incomplete. Here we report the cryo-electron microscopy structure of a tubular HIV-1 capsid-protein assembly at 8 Å resolution and the three-dimensional structure of a native HIV-1 core by cryo-electron tomography. The structure of the tubular assembly shows, at the three-fold interface, a three-helix bundle with critical hydrophobic interactions. Mutagenesis studies confirm that hydrophobic residues in the centre of the three-helix bundle are crucial for capsid assembly and stability, and for viral infectivity. The cryo-electron-microscopy structures enable modelling by large-scale molecular dynamics simulation, resulting in all-atom models for the hexamer-of-hexamer and pentamer-of-hexamer elements as well as for the entire capsid. Incorporation of pentamers results in closer trimer contacts and induces acute surface curvature. The complete atomic HIV-1 capsid model provides a platform for further studies of capsid function and for targeted pharmacological intervention.
Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15260, USA.