Structure of the RNA signal essential for translational frameshifting in HIV-1.
Many pathogenic viruses use a programmed -1 translational frameshifting mechanism to regulate synthesis of their structural and enzymatic proteins. Frameshifting is vital for viral replication. A slippery sequence bound at the ribosomal A and P sites as well as a downstream stimulatory RNA structure are essential for frameshifting. Conflicting data have been reported concerning the structure of the downstream RNA signal in human immunodeficiency virus type 1 (HIV-1). Here, the solution structure of the HIV-1 frameshifting RNA signal was solved by heteronuclear NMR spectroscopy. This structure reveals a long hairpin fold with an internal three-nucleotide bulge. The internal loop introduces a bend between the lower and upper helical regions, a structural feature often seen in frameshifting pseudoknots. The NMR structure correlates with chemical probing data. The upper stem rich in conserved G-C Watson-Crick base-pairs is highly stable, whereas the bulge region and the lower stem are more flexible.
Gaudin
Cyril
C
Laboratoire de RMN, ICSN-CNRS 1 ave de la terrasse, 91190 Gif-sur-Yvette, France.
Mazauric
Marie-Hélène
MH
Traïkia
Mounir
M
Guittet
Eric
E
Yoshizawa
Satoko
S
Fourmy
Dominique
D
D001482:Base Composition; D001483:Base Sequence; D018965:Frameshifting, Ribosomal; D015497:HIV-1 / Q000737:chemistry / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D009690:Nucleic Acid Conformation; D014176:Protein Biosynthesis; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics*; D012270:Ribosomes / Q000737:chemistry / Q000235:genetics
D012367:RNA, Viral