title: Recognition of the pre-miRNA structure by Drosophila Dicer-1.
abstract: Drosophila melanogaster has two Dicer proteins with specialized functions. Dicer-1 liberates miRNA-miRNA* duplexes from precursor miRNAs (pre-miRNAs), whereas Dicer-2 processes long double-stranded RNAs into small interfering RNA duplexes. It was recently demonstrated that Dicer-2 is rendered highly specific for long double-stranded RNA substrates by inorganic phosphate and a partner protein R2D2. However, it remains unclear how Dicer-1 exclusively recognize pre-miRNAs. Here we show that fly Dicer-1 recognizes the single-stranded terminal loop structure of pre-miRNAs through its N-terminal helicase domain, checks the loop size and measures the distance between the 3' overhang and the terminal loop. This unique mechanism allows fly Dicer-1 to strictly inspect the authenticity of pre-miRNA structures.
authors.affiliation: Institute of Molecular and Cellular Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
authors.forename: Akihisa
authors.initials: A
authors.lastname: Tsutsumi
authors.forename: Tomoko
authors.initials: T
authors.lastname: Kawamata
authors.forename: Natsuko
authors.initials: N
authors.lastname: Izumi
authors.forename: Hervé
authors.initials: H
authors.lastname: Seitz
authors.forename: Yukihide
authors.initials: Y
authors.lastname: Tomari
mesh_terms: D000818:Animals; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster; D035683:MicroRNAs / Q000737:chemistry / Q000235:genetics*; D020365:RNA Helicases / Q000235:genetics / Q000378:metabolism*; D043244:Ribonuclease III / Q000235:genetics / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D029721:Drosophila Proteins; D035683:MicroRNAs; C515033:Dcr-1 protein, Drosophila; D043244:Ribonuclease III; D020365:RNA Helicases