RNA recognition by an isolated alpha helix.
A 17 amino acid peptide containing the arginine-rich region of the HIV Rev protein binds specifically to Rev response element (RRE) RNA. Even though it is highly charged, the peptide forms an alpha helix in solution, but only when its N- and C-termini are modified to provide favorable electrostatic interactions with the helix macrodipole. Binding affinity for IIB RNA (the primary binding site within the RRE) increases with alpha helix content, whereas nonspecific binding affinity is independent of helix content. Binding of mutant peptides demonstrates that one threonine, one asparagine, and four arginine side chains are important for sequence-specific recognition. Transactivation of the HIV LTR using Tat-Rev peptide hybrids and the RRE IIB site indicates that the peptide adopts an alpha-helical conformation in vivo. The results suggest that interactions with the RNA backbone may help to orient the alpha helix in the major groove of RNA.
Tan
R
R
Department of Biochemistry and Biophysics, University of California, San Francisco 94143.
Chen
L
L
Buettner
J A
JA
Hudson
D
D
Frankel
A D
AD
D000595:Amino Acid Sequence; D001120:Arginine; D001483:Base Sequence; D015694:Gene Products, rev / Q000737:chemistry*; D015497:HIV-1 / Q000737:chemistry; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011392:Proline; D017433:Protein Structure, Secondary; D012313:RNA / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry*; D012045:Regulatory Sequences, Nucleic Acid; D054321:rev Gene Products, Human Immunodeficiency Virus
D015694:Gene Products, rev; D016601:RNA-Binding Proteins; D054321:rev Gene Products, Human Immunodeficiency Virus; D012313:RNA; D001120:Arginine; D011392:Proline