Journal Article

The structure and flexibility of conical HIV-1 capsids determined within intact virions

Glass, Bärbel, Hagen, Wim J. H., Mattei, Simone, Kräusslich, Hans-Georg, Briggs, John A. G.

2016

Overview

HIV-1 contains a cone-shaped capsid encasing the viral genome. This capsid is thought to follow fullerene geometry—a curved hexameric lattice of the capsid protein, CA, closed by incorporating 12 CA pentamers. Current models for core structure are based on crystallography of hexameric and cross-linked pentameric CA, electron microscopy of tubular CA arrays, and simulations. Here, we report subnanometer-resolution cryo-electron tomography structures of hexameric and pentameric CA within intact HIV-1 particles. Whereas the hexamer structure is compatible with crystallography studies, the pentamer forms using different interfaces. Determining multiple structures revealed how CA flexes to form the variably curved core shell. We show that HIV-1 CA assembles both aberrant and perfect fullerene cones, supporting models in which conical cores assemble de novo after maturation.

• Publisher: American Association for the Advancement of Science,The American Association for the Advancement of Science
• Subject: Arrays / Capsid - chemistry / Capsid - ultrastructure / Capsid Proteins - chemistry / Capsid Proteins - ultrastructure / Casing (process) / Crosslinking / Cryoelectron Microscopy / Crystal structure / Crystallography / Electron Microscope Tomography / Fullerenes / Fullerenes - chemistry / gag Gene Products, Human Immunodeficiency Virus - chemistry / gag Gene Products, Human Immunodeficiency Virus - ultrastructure / Genome, Viral / Genomics / HIV / HIV-1 - chemistry / HIV-1 - ultrastructure / Human immunodeficiency virus / Humans / Lattices / Lentivirus / Microscopy / Protein Conformation / Protein Multimerization / Proteins / Tomography / Virion - chemistry / Virion - ultrastructure