title: Hammerhead ribozyme: a three dimensional model based on photo-crosslinking data.
abstract: The hammerhead ribozyme is a small catalytic RNA motif made up of 3 base-paired stems connected by conserved sequences which are essential for catalysis. We have modelled its 3 dimensional structure, taking advantage of proximity data between several substrate and ribozyme residues determined by photo-crosslinking experiments. It is characterized by an Y shape of the 3 stems stabilized in the central core by a network of hydrogen bonds involving in particular 2 non Watson-Crick G:A base-pairs. The 5' conserved sequence CUGA makes a sharp turn, the G residue exchanging hydrogen bonds with a conserved base-pair of stem III. The substrate is stretched at the cleavage site. Overall this structure is consistent with that deduced from X-ray crystallography but differences are observed at the level of the CUGA turn.
authors.affiliation: Département organisation et expression du génome, Institut Jacques-Monod, CNRS-Université Denis-Diderot, Paris, France.
authors.forename: P
authors.initials: P
authors.lastname: Laugâa
authors.forename: A
authors.initials: A
authors.lastname: Woisard
authors.forename: J L
authors.initials: JL
authors.lastname: Fourrey
authors.forename: A
authors.initials: A
authors.lastname: Favre
mesh_terms: D003432:Cross-Linking Reagents / Q000737:chemistry*; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D010777:Photochemistry; D016337:RNA, Catalytic / Q000737:chemistry*; D012984:Software
chemical_list: D003432:Cross-Linking Reagents; D016337:RNA, Catalytic