title: Structural insights into Gemin5-guided selection of pre-snRNAs for snRNP assembly.
abstract: In cytoplasm, the survival of motor neuron (SMN) complex delivers pre-small nuclear RNAs (pre-snRNAs) to the heptameric Sm ring for the assembly of the ring complex on pre-snRNAs at the conserved Sm site [A(U)4-6G]. Gemin5, a WD40 protein component of the SMN complex, is responsible for recognizing pre-snRNAs. In addition, Gemin5 has been reported to specifically bind to the m7G cap. In this study, we show that the WD40 domain of Gemin5 is both necessary and sufficient for binding the Sm site of pre-snRNAs by isothermal titration calorimetry (ITC) and mutagenesis assays. We further determined the crystal structures of the WD40 domain of Gemin5 in complex with the Sm site or m7G cap of pre-snRNA, which reveal that the WD40 domain of Gemin5 recognizes the Sm site and m7G cap of pre-snRNAs via two distinct binding sites by respective base-specific interactions. In addition, we also uncovered a novel role of Gemin5 in escorting the truncated forms of U1 pre-snRNAs for proper disposal. Overall, the elucidated Gemin5 structures will contribute to a better understanding of Gemin5 in small nuclear ribonucleic protein (snRNP) biogenesis as well as, potentially, other cellular activities.
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, Hefei Science Center of CAS, Chinese Academy of Science, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, People's Republic of China.|Key Laboratory of Structural Biology, Hefei Science Center of CAS, Chinese Academy of Science, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, People's Republic of China.|Structural Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada.
authors.forename: Chao
authors.initials: C
authors.lastname: Xu
authors.affiliation: Department of Applied Biological Science, Graduate School of Agriculture and Global Innovation Research Organization, Tokyo University of Agriculture and Technology, Fuchu-Shi, Tokyo 183-8509, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Ishikawa
authors.affiliation: Department of Applied Biological Science, Graduate School of Agriculture and Global Innovation Research Organization, Tokyo University of Agriculture and Technology, Fuchu-Shi, Tokyo 183-8509, Japan.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Izumikawa
authors.affiliation: Structural Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.affiliation: Structural Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada.
authors.forename: Hao
authors.initials: H
authors.lastname: He
authors.affiliation: Department of Chemistry, Tokyo Metropolitan University, Hachiouji-shi, Tokyo 192-0397, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Nobe
authors.affiliation: Department of Chemistry, Tokyo Metropolitan University, Hachiouji-shi, Tokyo 192-0397, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Yamauchi
authors.affiliation: Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, USA.
authors.forename: Hanief M
authors.initials: HM
authors.lastname: Shahjee
authors.affiliation: Structural Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada.
authors.forename: Xian-Hui
authors.initials: XH
authors.lastname: Wu
authors.affiliation: Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, USA.
authors.forename: Yi-Tao
authors.initials: YT
authors.lastname: Yu
authors.affiliation: Department of Chemistry, Tokyo Metropolitan University, Hachiouji-shi, Tokyo 192-0397, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Isobe
authors.affiliation: Department of Applied Biological Science, Graduate School of Agriculture and Global Innovation Research Organization, Tokyo University of Agriculture and Technology, Fuchu-Shi, Tokyo 183-8509, Japan.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Takahashi
authors.affiliation: Structural Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada.|Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada.
authors.forename: Jinrong
authors.initials: J
authors.lastname: Min
mesh_terms: D001665:Binding Sites; D002460:Cell Line; D003460:Crystallization; D057809:HEK293 Cells; D006801:Humans; D008958:Models, Molecular; D017354:Point Mutation; D011485:Protein Binding; D000072417:Protein Domains / Q000235:genetics; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D012322:RNA Precursors / Q000737:chemistry / Q000378:metabolism*; D017411:Ribonucleoproteins, Small Nuclear / Q000096:biosynthesis / Q000378:metabolism*; D055532:SMN Complex Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D012322:RNA Precursors; D017411:Ribonucleoproteins, Small Nuclear; D055532:SMN Complex Proteins
keywords: SMN complex; WD40 domain; X-ray crystal structure