Document 0046
 DOCN  M9590046
 TI    Prokaryotic ribosomes recode the HIV-1 gag-pol-1 frameshift sequence by
       an E/P site post-translocation simultaneous slippage mechanism.
 DT    9509
 AU    Horsfield JA; Wilson DN; Mannering SA; Adamski FM; Tate WP; Department
       of Biochemistry, University of Otago, Dunedin, New; Zealand.
 SO    Nucleic Acids Res. 1995 May 11;23(9):1487-94. Unique Identifier :
       AIDSLINE MED/95303630
 AB    The mechanism favoured for -1 frameshifting at typical retroviral sites
       is a pre-translocation simultaneous slippage model. An alternative
       post-translocation mechanism would also generate the same protein
       sequence across the frameshift site and therefore in this study the
       strategic placement of a stop codon has been used to distinguish between
       the two mechanisms. A 26 base pair frameshift sequence from the HIV-1
       gag-pol overlap has been modified to include a stop codon immediately 3'
       to the heptanucleotide frameshift signal, where it often occurs
       naturally in retroviral recoding sites. Stop codons at the 3'-end of the
       heptanucleotide sequence decreased the frame-shifting efficiency on
       prokaryote ribosomes and the recording event was further depressed when
       the levels of the release factors in vivo were increased. In the
       presence of elevated levels of a defective release factor 2,
       frameshifting efficiency in vivo was increased in the constructs
       containing the stop codons recognized specifically by that release
       factor. These results are consistent with the last six nucleotides of
       the heptanucleotide slippery sequence occupying the ribosomal E and P
       sites, rather than the P and A sites, with the next codon occupying the
       A site and therefore with a post-translocation rather than a
       pre-translocation -1 slippage model.
 DE    Base Sequence  Codon/GENETICS  Escherichia coli/GENETICS  *Frameshift
       Mutation  HIV-1/*GENETICS/METABOLISM  Molecular Sequence Data
       Ribosomes/*GENETICS/METABOLISM  RNA, Messenger/GENETICS/METABOLISM
       Support, Non-U.S. Gov't  *Translation, Genetic  JOURNAL ARTICLE

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