title: Promotion of met-tRNAiMet binding to ribosomes by yIF2, a bacterial IF2 homolog in yeast.
abstract: Delivery of the initiator methionine transfer RNA (Met-tRNAiMet) to the ribosome is a key step in the initiation of protein synthesis. Previous results have indicated that this step is catalyzed by the structurally dissimilar translation factors in prokaryotes and eukaryotes-initiation factor 2 (IF2) and eukaryotic initiation factor 2 (eIF2), respectively. A bacterial IF2 homolog has been identified in both eukaryotes and archaea. By using a combination of molecular genetic and biochemical studies, the Saccharomyces cerevisiae IF2 homolog is shown to function in general translation initiation by promoting Met-tRNAiMet binding to ribosomes. Thus, the mechanism of protein synthesis in eukaryotes and prokaryotes is more similar than was previously realized.
authors.affiliation: Laboratory of Eukaryotic Gene Regulation, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-2716, USA.
authors.forename: S K
authors.initials: SK
authors.lastname: Choi
authors.forename: J H
authors.initials: JH
authors.lastname: Lee
authors.forename: W L
authors.initials: WL
authors.lastname: Zoll
authors.forename: W C
authors.initials: WC
authors.lastname: Merrick
authors.forename: T E
authors.initials: TE
authors.lastname: Dever
mesh_terms: D018387:Codon, Initiator; D003593:Cytoplasm / Q000737:chemistry; D004268:DNA-Binding Proteins; D015852:Eukaryotic Initiation Factor-2 / Q000378:metabolism / Q000494:pharmacology; D005656:Fungal Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D010442:Peptide Chain Initiation, Translational; D010448:Peptide Initiation Factors / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D039881:Prokaryotic Initiation Factor-2; D014176:Protein Biosynthesis; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D012358:RNA, Transfer, Met / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins
chemical_list: D018387:Codon, Initiator; D004268:DNA-Binding Proteins; D015852:Eukaryotic Initiation Factor-2; D005656:Fungal Proteins; C112736:Met-tRNA(i)(Met); D010448:Peptide Initiation Factors; D039881:Prokaryotic Initiation Factor-2; D012358:RNA, Transfer, Met; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D011494:Protein Kinases