       Document 0036
 DOCN  M9470036
 TI    Identification of the primary site of the human immunodeficiency virus
       type 1 RNA dimerization in vitro.
 DT    9409
 AU    Skripkin E; Paillart JC; Marquet R; Ehresmann B; Ehresmann C; Unite
       Propre de Recherche 9002 du Centre National de la; Recherche
       Scientifique, Institut de Biologie Moleculaire et; Cellulaire,
       Strasbourg, France.
 SO    Proc Natl Acad Sci U S A. 1994 May 24;91(11):4945-9. Unique Identifier :
       AIDSLINE MED/94255445
 AB    The diploid genome of all retroviruses is made of two homologous copies
       of RNA intimately associated near their 5' end, in a region called the
       dimer linkage structure. Dimerization of genomic RNA is thought to be
       important for crucial functions of the retroviral life cycle (reverse
       transcription, translation, encapsidation). Previous in vitro studies
       mapped the dimer linkage structure of human immunodeficiency virus type
       1 (HIV-1) in a region downstream of the splice donor site, containing
       conserved purine tracts that were postulated to mediate dimerization,
       through purine quartets. However, we recently showed that dimerization
       of HIV-1 RNA also involves sequences upstream of the splice donor site.
       Here, we used chemical modification interference to identify nucleotides
       that are required in unmodified form for dimerization of a RNA fragment
       containing nucleotides 1-707 of HIV-1 RNA. These nucleotides map
       exclusively in a restricted area upstream of the splice donor site and
       downstream of the primer binding site. They are centered around a
       palindromic sequence (GUGCAC279) located in a hairpin loop. Our results
       support a model in which dimer formation is initiated by the annealing
       of the palindromic sequences, possibly by a loop-loop interaction
       between the two monomers. Further experiments show that the deletion of
       the stem-loop or base substitutions in the loop abolish dimerization,
       despite the presence of the previously postulated dimer linkage
       structure. On the other hand, deletions of the purine tracts downstream
       of the splice donor site do not prevent dimerization. Therefore, we
       conclude that the palindromic region represents the dimerization
       initiation site of genomic RNA.
 DE    Base Sequence  Binding Sites  Biopolymers  HIV-1/*GENETICS  Molecular
       Sequence Data  Nucleic Acid Conformation  Nucleotides/CHEMISTRY
       Repetitive Sequences, Nucleic Acid  RNA, Viral/*CHEMISTRY  Support,
       Non-U.S. Gov't  JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

