Analysis of natural variants of the human immunodeficiency virus type 1 gag-pol frameshift stem-loop structure.
Human immunodeficiency virus type 1 uses ribosomal frameshifting for translation of the Gag-Pol polyprotein. Frameshift activities are thought to be tightly regulated. Analysis of gag p1 sequences from 270 plasma virions identified in 64% of the samples the occurrence of polymorphism that could lead to changes in thermodynamic stability of the stem-loop. Expression in Saccharomyces cerevisiae of p1-beta-galactosidase fusion proteins from 10 representative natural stem-loop variants and three laboratory mutant constructs (predicted the thermodynamic stability [Delta G degrees] ranging from -23.0 to -4.3 kcal/mol) identified a reduction in frameshift activity of 13 to 67% compared with constructs with the wild-type stem-loop (Delta G degrees, -23.5 kcal/mol). Viruses carrying stem-loops associated with greater than 60% reductions in frameshift activity presented profound defects in viral replication. In contrast, viruses with stem-loop structures associated with 16 to 42% reductions in frameshift efficiency displayed no significant viral replication deficit.
Telenti
Amalio
A
Division of Infectious Diseases and Institute of Microbiology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland. amalio.telenti@chuv.hospvd.ch
Martinez
Raquel
R
Munoz
Miguel
M
Bleiber
Gabriela
G
Greub
Gilbert
G
Sanglard
Dominique
D
Peters
Solange
S
D001483:Base Sequence; D018965:Frameshifting, Ribosomal; D015750:Genes, gag / Q000235:genetics*; D015751:Genes, pol / Q000235:genetics* / Q000502:physiology; D014644:Genetic Variation; D015497:HIV-1 / Q000235:genetics* / Q000472:pathogenicity; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000821:virology; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009690:Nucleic Acid Conformation; D013816:Thermodynamics; D014771:Virion / Q000378:metabolism; D014779:Virus Replication