Gongpu Zhao, Juan R. Perilla, Ernest L. Yufenyuy, Xin Meng, Bo Chen, Jiying
Ning, Jinwoo Ahn, Angela M. Gronenborn, Klaus Schulten, Christopher Aiken,
and Peijun Zhang.
Mature HIV-1 capsid structure by cryo-electron microscopy and
all-atom molecular dynamics.
Nature, 497:643-646, 2013.
(PMC: 3729984)
ZHAO2013
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 -helices and a -hairpin, a carboxy-terminal domain (CTD)
comprising four -helices, and a flexible linker with a 3-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.
Download Full Text
The manuscripts available on our site are provided for your personal
use only and may not be retransmitted or redistributed without written
permissions from the paper's publisher and author. You may not upload any
of this site's material to any public server, on-line service, network, or
bulletin board without prior written permission from the publisher and
author. You may not make copies for any commercial purpose. Reproduction
or storage of materials retrieved from this web site is subject to the
U.S. Copyright Act of 1976, Title 17 U.S.C.