Structural Insights into the HIV-1 Minus-strand Strong-stop DNA.
J Biol Chem
; 291(7): 3468-82, 2016 Feb 12.
Article
em En
| MEDLINE
| ID: mdl-26668324
ABSTRACT
An essential step of human immunodeficiency virus type 1 (HIV-1) reverse transcription is the first strand transfer that requires base pairing of the R region at the 3'-end of the genomic RNA with the complementary r region at the 3'-end of minus-strand strong-stop DNA (ssDNA). HIV-1 nucleocapsid protein (NC) facilitates this annealing process. Determination of the ssDNA structure is needed to understand the molecular basis of NC-mediated genomic RNA-ssDNA annealing. For this purpose, we investigated ssDNA using structural probes (nucleases and potassium permanganate). This study is the first to determine the secondary structure of the full-length HIV-1 ssDNA in the absence or presence of NC. The probing data and phylogenetic analysis support the folding of ssDNA into three stem-loop structures and the presence of four high-affinity binding sites for NC. Our results support a model for the NC-mediated annealing process in which the preferential binding of NC to four sites triggers unfolding of the three-dimensional structure of ssDNA, thus facilitating interaction of the r sequence of ssDNA with the R sequence of the genomic RNA. In addition, using gel retardation assays and ssDNA mutants, we show that the NC-mediated annealing process does not rely on a single pathway (zipper intermediate or kissing complex).
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MEDLINE
Assunto principal:
DNA de Cadeia Simples
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DNA Viral
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Modelos Moleculares
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HIV-1
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Códon de Terminação
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Proteínas do Nucleocapsídeo
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Produtos do Gene gag do Vírus da Imunodeficiência Humana
Idioma:
En
Revista:
J Biol Chem
Ano de publicação:
2016
Tipo de documento:
Article