title: Structure and interactions of the translation initiation factor eIF1.
abstract: eIF1 is a universally conserved translation factor that is necessary for scanning and involved in initiation site selection. We have determined the solution structure of human eIF1 with an N-terminal His tag using NMR spectroscopy. Residues 29-113 of the native sequence form a tightly packed domain with two alpha-helices on one side of a five-stranded parallel and antiparallel beta-sheet. The fold is new but similar to that of several ribosomal proteins and RNA-binding domains. A likely binding site is indicated by yeast mutations and conserved residues located together on the surface. No interaction with recombinant eIF5 or the initiation site RNA GCCACAAUGGCA was detected by NMR, but GST pull-down experiments show that eIF1 binds specifically to the p110 subunit of eIF3. This interaction explains how eIF1 is recruited to the 40S ribosomal subunit.
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: C M
authors.initials: CM
authors.lastname: Fletcher
authors.forename: T V
authors.initials: TV
authors.lastname: Pestova
authors.forename: C U
authors.initials: CU
authors.lastname: Hellen
authors.forename: G
authors.initials: G
authors.lastname: Wagner
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D017124:Conserved Sequence; D015977:Eukaryotic Initiation Factor-1 / Q000737:chemistry*; D039621:Eukaryotic Initiation Factor-3; D040061:Eukaryotic Initiation Factor-5; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D010442:Peptide Chain Initiation, Translational; D010448:Peptide Initiation Factors / Q000378:metabolism; D017510:Protein Folding; D017433:Protein Structure, Secondary; D016601:RNA-Binding Proteins / Q000737:chemistry*; D012270:Ribosomes
chemical_list: D015977:Eukaryotic Initiation Factor-1; D039621:Eukaryotic Initiation Factor-3; D040061:Eukaryotic Initiation Factor-5; D010448:Peptide Initiation Factors; D016601:RNA-Binding Proteins