Structure and assembly of immature HIV.
The major structural components of HIV are synthesized as a 55-kDa polyprotein, Gag. Particle formation is driven by the self-assembly of Gag into a curved hexameric lattice, the structure of which is poorly understood. We used cryoelectron tomography and contrast-transfer-function corrected subtomogram averaging to study the structure of the assembled immature Gag lattice to approximately 17-A resolution. Gag is arranged in the immature virus as a single, continuous, but incomplete hexameric lattice whose curvature is mediated without a requirement for pentameric defects. The resolution of the structure allows positioning of individual protein domains. High-resolution crystal structures were fitted into the reconstruction to locate protein-protein interfaces involved in Gag assembly, and to identify the structural transformations associated with virus maturation. The results of this study suggest a concept for the formation of nonsymmetrical enveloped viruses of variable sizes.
Briggs
J A G
JA
Structural and Computational Biology Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany. briggs@embl.de
Riches
J D
JD
Glass
B
B
Bartonova
V
V
Zanetti
G
G
Kräusslich
H-G
HG
D002213:Capsid / Q000737:chemistry; D002460:Cell Line; D019281:Dimerization; D015497:HIV-1 / Q000737:chemistry* / Q000502:physiology*; D006801:Humans; D008958:Models, Molecular; D017434:Protein Structure, Tertiary; D014054:Tomography; D014771:Virion / Q000737:chemistry; D019065:Virus Assembly; D054301:gag Gene Products, Human Immunodeficiency Virus / Q000737:chemistry
D054301:gag Gene Products, Human Immunodeficiency Virus