Document 0931
 DOCN  M9540931
 TI    Binding of the HIV-1 nucleocapsid protein to the primer tRNA(3Lys), in
       vitro, is essentially not specific.
 DT    9504
 AU    Mely Y; de Rocquigny H; Sorinas-Jimeno M; Keith G; Roques BP; Marquet R;
       Gerard D; Laboratoire de Biophysique, URA 491 du CNRS, Universite Louis;
       Pasteur de Strasbourg I, Faculte de Pharmacie, Illkirch, France.
 SO    J Biol Chem. 1995 Jan 27;270(4):1650-6. Unique Identifier : AIDSLINE
       MED/95130539
 AB    The nucleocapsid protein NCp7 of human immunodeficiency virus, type 1,
       is a key component in the viral life cycle. Since, the first common step
       of all reported NCp7 activities corresponds to a nucleic acid-binding
       step, the NCp7 binding parameters to the natural primer tRNA(3Lys) were
       investigated. Using NCp7 intrinsic fluorescence, we found that (i) in
       0.1 M NaCl, NCp7 bound noncooperatively to tRNA(3Lys) with a Kobs = 3.2
       x 10(6) M-1 association constant and a n = 6 binding site size, (ii)
       four ionic interactions were formed in the NCp7.tRNA(3Lys) complex, and
       (iii) nonelectrostatic factors provided about 60% of the binding energy.
       These binding parameters were not significantly altered when the natural
       tRNA(3Lys) was replaced by either an in vitro synthetic tRNA(3Lys)
       transcript, the heterologous yeast tRNA(Phe) or the structurally
       unrelated 5 S RNA from Escherichia coli. Moreover, the environment of
       the intrinsic fluorescent reporters (Trp37 and Trp61) was similar in the
       various complexes. Finally, experiments performed at low protein
       concentration provide no evidence of high affinity binding sites. Taken
       together, our data strongly suggested an essentially nonspecific binding
       of NCp7 to tRNA(3Lys) and thus did not seem to support a direct role of
       NCp7, per se, in the selection of tRNA(3Lys) from the pool of cellular
       tRNAs.
 DE    Amino Acid Sequence  Capsid/*CHEMISTRY/*METABOLISM  Escherichia coli
       Gene Products, gag/*CHEMISTRY/*METABOLISM  Hydrogen-Ion Concentration
       HIV-1/*METABOLISM  Kinetics  Magnesium Chloride/PHARMACOLOGY
       Mathematics  Models, Theoretical  Molecular Sequence Data  Nucleic Acid
       Conformation  Osmolar Concentration  Protein Binding  RNA, Transfer,
       Amino Acyl/BIOSYNTHESIS/CHEMISTRY/*METABOLISM  Substrate Specificity
       Support, Non-U.S. Gov't  Transcription, Genetic  Zinc Fingers  JOURNAL
       ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
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