Requirements for RNA heterodimerization of the human immunodeficiency virus type 1 (HIV-1) and HIV-2 genomes.
Retroviruses are prone to recombination because they package two copies of the RNA genome. Whereas recombination is a frequent event within the human immunodeficiency virus type 1 (HIV-1) and HIV-2 groups, no HIV-1/HIV-2 recombinants have been reported thus far. The possibility of forming HIV-1/HIV-2 RNA heterodimers was studied in vitro. In both viruses, the dimer initiation site (DIS) hairpin is used to form dimers, but these motifs appear too dissimilar to allow RNA heterodimer formation. Multiple mutations were introduced into the HIV-2 DIS element to gradually mimic the HIV-1 hairpin. First, the loop-exposed palindrome of HIV-1 was inserted. This self-complementary sequence motif forms the base pair interactions of the kissing-loop (KL) dimer complex, but such a modification is not sufficient to permit RNA heterodimer formation. Next, the HIV-2 DIS loop size was shortened from 11 to 9 nucleotides, as in the HIV-1 DIS motif. This modification also results in the presentation of the palindromes in the same position within the hairpin loop. The change yielded a modest level of RNA heterodimers, which was not significantly improved by additional sequence changes in the loop and top base pair. No isomerization of the KL dimer to the extended duplex dimer form was observed for the heterodimers. These combined results indicate that recombination between HIV-1 and HIV-2 is severely restricted at the level of RNA dimerization.
Dirac
Annette M G
AMG
Department of Human Retrovirology, Academic Medical Center, University of Amsterdam, PO Box 22700, 1100 DE Amsterdam, The Netherlands2.|Department of Molecular and Structural Biology, Aarhus University, , Denmark1.
Huthoff
Hendrik
H
Department of Human Retrovirology, Academic Medical Center, University of Amsterdam, PO Box 22700, 1100 DE Amsterdam, The Netherlands2.
Kjems
Jørgen
J
Department of Molecular and Structural Biology, Aarhus University, , Denmark1.
Berkhout
Ben
B
Department of Human Retrovirology, Academic Medical Center, University of Amsterdam, PO Box 22700, 1100 DE Amsterdam, The Netherlands2.
D020029:Base Pairing; D001483:Base Sequence; D019281:Dimerization; D016679:Genome, Viral; D015497:HIV-1 / Q000235:genetics*; D015498:HIV-2 / Q000235:genetics*; D006801:Humans; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012367:RNA, Viral / Q000737:chemistry
D012367:RNA, Viral