7-methylguanosine-triphosphate and 7-methylguanosine

7-methylguanosine-triphosphate has been researched along with 7-methylguanosine* in 2 studies

Other Studies

2 other study(ies) available for 7-methylguanosine-triphosphate and 7-methylguanosine

ArticleYear
The 5'-7-methylguanosine cap on eukaryotic mRNAs serves both to stimulate canonical translation initiation and to block an alternative pathway.
    Molecular cell, 2010, Sep-24, Volume: 39, Issue:6

    Translational control is frequently exerted at the stage of mRNA recruitment to the initiating ribosome. We have reconstituted mRNA recruitment to the 43S preinitiation complex (PIC) using purified S. cerevisiae components. We show that eIF3 and the eIF4 factors not only stabilize binding of mRNA to the PIC, they also dramatically increase the rate of recruitment. Although capped mRNAs require eIF3 and the eIF4 factors for efficient recruitment to the PIC, uncapped mRNAs can be recruited in the presence of eIF3 alone. The cap strongly inhibits this alternative recruitment pathway, imposing a requirement for the eIF4 factors for rapid and stable binding of natural mRNA. Our data suggest that the 5' cap serves as both a positive and negative element in mRNA recruitment, promoting initiation in the presence of the canonical group of mRNA handling factors while preventing binding to the ribosome via an aberrant, alternative pathway requiring only eIF3.

    Topics: Cell-Free System; Eukaryotic Initiation Factor-3; Eukaryotic Initiation Factor-4A; Eukaryotic Initiation Factor-4E; Eukaryotic Initiation Factor-4F; Eukaryotic Initiation Factor-4G; Eukaryotic Initiation Factors; Gene Expression Regulation, Fungal; Guanosine; Kinetics; Nucleic Acid Conformation; Peptide Chain Initiation, Translational; Protein Binding; Protein Interaction Domains and Motifs; Ribosomal Proteins; Ribosome Subunits, Small, Eukaryotic; RNA Cap Analogs; RNA Caps; RNA, Fungal; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins

2010
Charge distribution in 7-methylguanine regarding cation-pi interaction with protein factor eIF4E.
    Biophysical journal, 2003, Volume: 85, Issue:3

    Electric charge distribution in mRNA 5' cap terminus has been exhaustively characterized in respect to the affinity for cap-binding proteins. Formation of the stacked configuration of positively charged 7-methylguanine in between two aromatic amino acid rings, known as sandwich cation-pi stacking, is thought to be prerequisite for the specific recognition of the cap by eukaryotic initiation factor eIF4E; i.e., discrimination between the cap and nucleotides without the methyl group at N(7). Nuclear magnetic resonance spectroscopy of (15)N/(13)C-double-labeled 7-methylguanosine 5'-triphosphate and 7-methylguanosine, as well as their unsubstituted counterparts, GTP and guanosine, yielded characteristic changes of the electron-mediated spin-spin couplings and chemical shifts due to the methylation at N(7). The experimentally measured changes of the nuclear magnetic resonance parameters have been analyzed in respect to the electric charge distribution calculated by means of quantum chemical methods, and interpreted in terms of new proposed positive charge localization in the 7-methylguanine five-member ring.

    Topics: Biophysical Phenomena; Biophysics; Carbon; Cations; Electrons; Eukaryotic Initiation Factor-4E; Guanine; Guanosine; Guanosine Triphosphate; Hydrogen-Ion Concentration; Magnetic Resonance Spectroscopy; Methylation; Models, Chemical; RNA Cap Analogs; RNA Caps; RNA, Messenger; Temperature

2003