title: The RNA-binding region of human TRBP interacts with microRNA precursors through two independent domains.
abstract: MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression through RNA interference. Human miRNAs are generated through a series of enzymatic processing steps. The precursor miRNA (pre-miRNA) is recognized and cleaved by a complex containing Dicer and several non-catalytic accessory proteins. HIV TAR element binding protein (TRBP) is a constituent of the Dicer complex, which augments complex stability and potentially functions in substrate recognition and product transfer to the RNA-induced silencing complex. Here we have analysed the interaction between the RNA-binding region of TRBP and an oncogenic human miRNA, miR-155, at different stages in the biogenesis pathway. We show that the region of TRBP that binds immature miRNAs comprises two independent double-stranded RNA-binding domains connected by a 60-residue flexible linker. No evidence of contact between the two double-stranded RNA-binding domains was observed either in the apo- or RNA-bound state. We establish that the RNA-binding region of TRBP interacts with both pre-miR-155 and the miR-155/miR-155* duplex through the same binding surfaces and with similar affinities, and that two protein molecules can simultaneously interact with each immature miRNA. These data suggest that TRBP could play a role before and after processing of pre-miRNAs by Dicer.
authors: CEA, Institut de Biologie Structurale Jean-Pierre Ebel, Grenoble, France.
authors: Matthieu P M H
authors: MP
authors: Benoit
authors: Lionel
authors: L
authors: Imbert
authors: Andrés
authors: A
authors: Palencia
authors: Julien
authors: J
authors: Pérard
authors: Christine
authors: C
authors: Ebel
authors: Jérôme
authors: J
authors: Boisbouvier
authors: Michael J
authors: MJ
authors: Plevin
mesh_terms: D001665:Binding Sites; D006801:Humans; D035683:MicroRNAs / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D012322:RNA Precursors / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism*; D043244:Ribonuclease III / Q000378:metabolism; D000099253:Trans-Activation Responsive RNA-Binding Protein
chemical_list: D035683:MicroRNAs; D012322:RNA Precursors; D016601:RNA-Binding Proteins; D043244:Ribonuclease III; D000099253:Trans-Activation Responsive RNA-Binding Protein; C524942:MIRN155 microRNA, human