Document 0347
 DOCN  M9460347
 TI    Helix-loop-helix motif in HIV-1 Rev.
 DT    9404
 AU    Auer M; Gremlich HU; Seifert JM; Daly TJ; Parslow TG; Casari G; Gstach
       H; Sandoz Research Institute, Vienna, Austria.
 SO    Biochemistry. 1994 Mar 15;33(10):2988-96. Unique Identifier : AIDSLINE
       MED/94176492
 AB    Circular dichroism (CD) spectra of C-terminal deletion mutants of the
       HIV-1 Rev protein, Rev M9 delta 14 (missing aa 68-112) and Rev M11 delta
       14 (lacking aa 92-112), indicated that Rev contains 46-49 residues in
       alpha-helical conformation within the N-terminal 71 or 95 amino acids of
       the 116 residue protein. Complexation with a 40-nucleotide fragment of
       the Rev responsive element, RRE, (G39 to C78), containing the minimal
       element for Rev binding, induced an A to B form structural transition in
       the RRE fragment, whereas the percentage of alpha-helical conformation
       in the protein stays constant on substrate binding. When complexed to
       the RNA, neither mutant protein showed structural changes upon raising
       the temperature to 40 degrees C, as determined by the lack of decrease
       of the signal intensity at 222 nm, indicative for alpha-helical
       conformation. In contrast, Rev M9 delta 14, which is shorter than Rev
       M11 delta 14 by 24 amino acids, in the absence of RNA, lost about 60% of
       the spectral minima at 222 nm at the same temperature. The Rev M11 delta
       14 mutant, in the absence of RNA, showed a decrease of 20% in spectral
       intensity upon heating to 40 degrees C. Free and RNA-bound mutant
       proteins showed reversible transitions upon heating to 80 degrees C and
       subsequent cooling down to 10 degrees C overnight. The Rev peptide Cys
       75-93, spanning the Rev transactivation domain, showed secondary
       structure in 40% and 60% hexafluoropropanol (HFP) solutions.(ABSTRACT
       TRUNCATED AT 250 WORDS)
 DE    Amino Acid Sequence  Base Sequence  Circular Dichroism  Gene Products,
       rev/BIOSYNTHESIS/*CHEMISTRY/METABOLISM  *Helix-Loop-Helix Motifs
       HIV-1/*METABOLISM  Molecular Sequence Data  Nucleic Acid Conformation
       Peptide Fragments/CHEMISTRY/CHEMICAL SYNTHESIS  Protein Conformation
       Recombinant Proteins/BIOSYNTHESIS/CHEMISTRY/METABOLISM
       RNA/*CHEMISTRY/METABOLISM  Sequence Deletion  Trans-Activation
       (Genetics)  JOURNAL ARTICLE

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