title: Structure of the RNA signal essential for translational frameshifting in HIV-1.
abstract: 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.
authors.affiliation: Laboratoire de RMN, ICSN-CNRS 1 ave de la terrasse, 91190 Gif-sur-Yvette, France.
authors.forename: Cyril
authors.initials: C
authors.lastname: Gaudin
authors.forename: Marie-Hélène
authors.initials: MH
authors.lastname: Mazauric
authors.forename: Mounir
authors.initials: M
authors.lastname: Traïkia
authors.forename: Eric
authors.initials: E
authors.lastname: Guittet
authors.forename: Satoko
authors.initials: S
authors.lastname: Yoshizawa
authors.forename: Dominique
authors.initials: D
authors.lastname: Fourmy
mesh_terms: 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
chemical_list: D012367:RNA, Viral