title: Catalytic activity of an RNA domain derived from the U6-U4 RNA complex.
abstract: U6 RNA contains two regions that are essential for proper splicing of nuclear precursor messenger RNA (pre-mRNA). A comparison of putative secondary structures of the U6-U4 RNA complexes from different phyla revealed a conserved domain that is similar to the catalytic hammerhead RNA motif. Although no catalytic activity was detected in the mammalian U6-U4 RNA complexes, two nucleotide changes in U6 RNA and one in U4 RNA conferred cleavage activity to the complex. Furthermore, the highly conserved domain of the wild-type complex, without the accompanying flanking regions, cleaved an RNA substrate and exhibited other characteristics of the hammerhead ribozyme. The possible involvement of this structure in pre-mRNA splicing is also discussed.
authors.affiliation: Howard Hughes Medical Institute, Department of Cellular and Molecular Physiology, Harvard Medical School, Boston, MA.
authors.forename: J H
authors.initials: JH
authors.lastname: Yang
authors.forename: R
authors.initials: R
authors.lastname: Cedergren
authors.forename: B
authors.initials: B
authors.lastname: Nadal-Ginard
mesh_terms: D001483:Base Sequence; D006801:Humans; D007438:Introns; D008274:Magnesium / Q000378:metabolism; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012326:RNA Splicing; D016337:RNA, Catalytic / Q000737:chemistry / Q000378:metabolism*; D012342:RNA, Small Nuclear / Q000737:chemistry / Q000378:metabolism*; D015003:Yeasts / Q000235:genetics
chemical_list: D016337:RNA, Catalytic; D012342:RNA, Small Nuclear; D008274:Magnesium