A short autocomplementary sequence in the 5' leader region is responsible for dimerization of MoMuLV genomic RNA.
Previous work has shown that a region of Moloney murine leukemia virus (MoMuLV) RNA located between nucleotides 280 and 330 in the PSI region (nt 215-565) is implicated in the dimerization process. We show with a deletion from nucleotides 290-299 in PSI RNA transcripts and through an antisense oligonucleotide complementary to nucleotides 275-291 that the 283-298 region is involved in RNA dimer formation in vitro. In an attempt to further characterize the mechanism of dimer formation, a series of short RNA transcripts was synthesized which overlapps the PSI region of MoMuLV RNA. The dimerization of these RNAs is temperature dependent. The predicted secondary structure of the 278-303 region, as a function of temperature, reveals that this sequence is able to adopt two conformations: (1) the U288 AGCUA293 sequence in a loop; (2) part of the same nucleotides implicated in a stem. These results, together with thermodynamic analysis, strongly suggest that (1) the loop conformation of the UAGCUA sequence modulates the relative amount of RNA dimer and (2) a 16 bp long Watson-Crick base pairing is involved in RNA dimer formation. We propose that loop-loop recognition via the U288 AGCUA293 sequence leads to a stable structure induced by a stem-loop opening. Furthermore, our results do not support purine quartet formation as necessary for the dimerization of the 5' leader MoMuLV RNA.
Girard
P M
PM
Unité de Biochimie, URA 147 CNRS, Institut Gustave Roussy, Villejuif, France.
Bonnet-Mathonière
B
B
Muriaux
D
D
Paoletti
J
J
D001482:Base Composition; D001483:Base Sequence; D017353:Gene Deletion; D007700:Kinetics; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D008979:Moloney murine leukemia virus / Q000235:genetics*; D009690:Nucleic Acid Conformation; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D021382:Protein Sorting Signals / Q000235:genetics*; D012367:RNA, Viral / Q000737:chemistry*; D013816:Thermodynamics
D046911:Macromolecular Substances; D016376:Oligonucleotides, Antisense; D021382:Protein Sorting Signals; D012367:RNA, Viral