title: Molecular Landscape of the Ribosome Pre-initiation Complex during mRNA Scanning: Structural Role for eIF3c and Its Control by eIF5.
abstract: During eukaryotic translation initiation, eIF3 binds the solvent-accessible side of the 40S ribosome and recruits the gate-keeper protein eIF1 and eIF5 to the decoding center. This is largely mediated by the N-terminal domain (NTD) of eIF3c, which can be divided into three parts: 3c0, 3c1, and 3c2. The N-terminal part, 3c0, binds eIF5 strongly but only weakly to the ribosome-binding surface of eIF1, whereas 3c1 and 3c2 form a stoichiometric complex with eIF1. 3c1 contacts eIF1 through Arg-53 and Leu-96, while 3c2 faces 40S protein uS15/S13, to anchor eIF1 to the scanning pre-initiation complex (PIC). We propose that the 3c0:eIF1 interaction diminishes eIF1 binding to the 40S, whereas 3c0:eIF5 interaction stabilizes the scanning PIC by precluding this inhibitory interaction. Upon start codon recognition, interactions involving eIF5, and ultimately 3c0:eIF1 association, facilitate eIF1 release. Our results reveal intricate molecular interactions within the PIC, programmed for rapid scanning-arrest at the start codon.
authors.affiliation: Shimane University School of Medicine, Izumo, Shimane 690-8504, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Obayashi
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Rafael E
authors.initials: RE
authors.lastname: Luna
authors.affiliation: Institute of Advanced Energy, Kyoto University, Uji, Kyoto 611-0011, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Nagata
authors.affiliation: Laboratory of Gene Regulation and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Pilar
authors.initials: P
authors.lastname: Martin-Marcos
authors.affiliation: Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Hiraishi
authors.affiliation: Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA.
authors.forename: Chingakham Ranjit
authors.initials: CR
authors.lastname: Singh
authors.affiliation: Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Jan Peter
authors.initials: JP
authors.lastname: Erzberger
authors.affiliation: Laboratory of Gene Regulation and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Fan
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Haribabu
authors.initials: H
authors.lastname: Arthanari
authors.affiliation: Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA.
authors.forename: Jacob
authors.initials: J
authors.lastname: Morris
authors.affiliation: California Institute for Quantitative Biosciences, University of California, San Francisco, San Francisco, CA 94158, USA.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Pellarin
authors.affiliation: Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA.
authors.forename: Chelsea
authors.initials: C
authors.lastname: Moore
authors.affiliation: Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA.
authors.forename: Ian
authors.initials: I
authors.lastname: Harmon
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Evangelos
authors.initials: E
authors.lastname: Papadopoulos
authors.affiliation: Graduate School of Medical Life Science, Yokohama City University, Tsurumi-ku, Yokohama 230-0045, Japan; Drug Design Group, Kanagawa Academy of Science and Technology, Takatsu-ku, Kawasaki 213-0012, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Yoshida
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Mahmoud L
authors.initials: ML
authors.lastname: Nasr
authors.affiliation: Graduate School of Medical Life Science, Yokohama City University, Tsurumi-ku, Yokohama 230-0045, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Unzai
authors.affiliation: Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA.
authors.forename: Brytteny
authors.initials: B
authors.lastname: Thompson
authors.affiliation: Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Aube
authors.affiliation: Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA.
authors.forename: Samantha
authors.initials: S
authors.lastname: Hustak
authors.affiliation: Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Florian
authors.initials: F
authors.lastname: Stengel
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Eddie
authors.initials: E
authors.lastname: Dagraca
authors.affiliation: COBRE-PSF, University of Kansas, Lawrence, KS 66047, USA.
authors.forename: Asokan
authors.initials: A
authors.lastname: Ananbandam
authors.affiliation: COBRE-PSF, University of Kansas, Lawrence, KS 66047, USA.
authors.forename: Philip
authors.initials: P
authors.lastname: Gao
authors.affiliation: Shimane University School of Medicine, Izumo, Shimane 690-8504, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Urano
authors.affiliation: Laboratory of Gene Regulation and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Alan G
authors.initials: AG
authors.lastname: Hinnebusch
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Wagner
authors.affiliation: Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA. Electronic address: kasano@ksu.edu.
authors.forename: Katsura
authors.initials: K
authors.lastname: Asano
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D015977:Eukaryotic Initiation Factor-1 / Q000378:metabolism; D039621:Eukaryotic Initiation Factor-3 / Q000737:chemistry* / Q000378:metabolism*; D040061:Eukaryotic Initiation Factor-5 / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009154:Mutation / Q000235:genetics; D010442:Peptide Chain Initiation, Translational; D011485:Protein Binding; D021122:Protein Subunits / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D012270:Ribosomes / Q000737:chemistry* / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism
chemical_list: D015977:Eukaryotic Initiation Factor-1; D039621:Eukaryotic Initiation Factor-3; D040061:Eukaryotic Initiation Factor-5; D021122:Protein Subunits; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins
keywords: eIF1; eIF3; eIF5; ribosomal pre-initiation complex; ribosome; start codon selection; translation initiation