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A conformational switch controlling HIV‐1 morphogenesis
Author(s) -
Gross Ingolf,
Hohenberg Heinz,
Wilk Thomas,
Wiegers Klaus,
Grättinger Mira,
Müller Barbara,
Fuller Stephen,
Kräusslich HansGeorg
Publication year - 2000
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/19.1.103
Subject(s) - biology , morphogenesis , human immunodeficiency virus (hiv) , microbiology and biotechnology , conformational change , biophysics , genetics , virology , gene
Assembly of infectious human immunodeficiency virus type 1 (HIV‐1) proceeds in two steps. Initially, an immature virus with a spherical capsid shell consisting of uncleaved Gag polyproteins is formed. Extracellular proteolytic maturation causes rearrangement of the inner virion structure, leading to the conical capsid of the infectious virus. Using an in vitro assembly system, we show that the same HIV‐1 Gag‐derived protein can form spherical particles, virtually indistinguishable from immature HIV‐1 capsids, as well as tubular or conical particles, resembling the mature core. The assembly phenotype could be correlated with differential binding of the protein to monoclonal antibodies recognizing epitopes in the HIV‐1 capsid protein (CA), suggesting distinct conformations of this domain. Only tubular and conical particles were observed when the protein lacked spacer peptide SP1 at the C‐terminus of CA, indicating that SP1 may act as a molecular switch, whose presence determines spherical capsid formation, while its cleavage leads to maturation.