Genomes and Genes
Structure of Eukaryotic Translation Elongation Factor 1
Principal Investigator: TERRI KINZY
Abstract: Recently, the structural basis of protein synthesis in prokaryotes has been illuminated by a series of structures of the soluble translation factors and the ribosome itself. A similar understanding of the more complicated and highly regulated steps of eukaryotic protein synthesis is just beginning. The goal of this project is to understand the structural basis for the function and regulation of the eukaryotic translation Elongation Factor 1A (eEF1A). eEF1A is a prototypic G-protein that performs functions not only in translation but also tRNA export, viral replication and cytoskeletal organization. Thus, it is clear that the cell needs to modulate the activity or levels of eEF1A for normal cellular growth. The regeneration of active eEF1A by the guanine nucleotide exchange factor eEF1B is illuminated by our structure of Saccharomyces cerevisiae eEF1A complexed with the catalytic fragment of the eEF1Balpha subunit. We propose to produce structures of eEF1A in complex with 1) GDP or the GTP analogue GDPNP 2) aminoacyl-tRNA (aa-tRNA) and GDPNP, 3) the complete guanine nucleotide exchange factor eEF1B and 4) actin. As a G-protein, eEF1A switches between active and inactive forms The based on whether GDP or GTP is bound. Hence, understand the structural switch between the forms will help elucidate the regulation of binding to the ribosome and aa-tRNA. The GTP form binds aa-tRNA, and the structure of this complex will illuminate the overall tertiary structure of the complex that binds the ribosomal A-site and senses a proper codon-anticodon interaction. The structure of the entire eEF1AB complex will help determine the function of the eEF1Bgamma subunit, a protein highly conserved in all eucaryotes but only recently implicated in perhaps modulating translational accuracy and the stress response. Lastly, the growing evidence of alternative functions of the translational apparatus, and in particular the ability of eEF1A to bind and bundle actin, leads us to expand out analysis to understand the structural basis of this association. With S. cerevisiae, the structural information obtained on eEF1A can be utilized for molecular genetic analysis of the critical residues for function and regulation.
Funding Period: 2001-06-01 - 2006-05-31
more information: NIH RePORT
- Mg2+ and a key lysine modulate exchange activity of eukaryotic translation elongation factor 1B alphaYvette R Pittman
Department of Molecular Genetics, Microbiology and Immunology, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway 08854, USA
J Biol Chem 281:19457-68. 2006..These results indicate the significant role of Mg2+ in the nucleotide exchange reaction by eEF1B alpha and establish the catalytic function of Lys-205 in displacing Mg2+ from its binding site...
- Novel characteristics of the biological properties of the yeast Saccharomyces cerevisiae eukaryotic initiation factor 2AAnton A Komar
Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA
J Biol Chem 280:15601-11. 2005..It was hypothesized that this instability allows for translational control through the level of eIF2A protein in yeast cells...
- Translation elongation factor 1A is essential for regulation of the actin cytoskeleton and cell morphologyStephane R Gross
Department of Molecular Genetics, Microbiology and Immunology, University of Medicine and Dentistry of New Jersey Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, USA
Nat Struct Mol Biol 12:772-8. 2005..This demonstrates for the first time a direct consequence of eEF1A on cytoskeletal organization in vivo and the physiological significance of this interaction...
- Dominant-negative mutant phenotypes and the regulation of translation elongation factor 2 levels in yeastPedro A Ortiz
Department of Molecular Genetics, Microbiology and Immunology, UMDNJ Robert Wood Johnson Medical School 675 Hoes Lane, Piscataway, NJ 08854 5635, USA
Nucleic Acids Res 33:5740-8. 2005..The observed regulation suggests that the cell needs an optimum amount of active eEF2 to grow properly. This provides information about a new mechanism by which translation is efficiently maintained...
- Rapid depletion of mutant eukaryotic initiation factor 5A at restrictive temperature reveals connections to actin cytoskeleton and cell cycle progressionIshita Chatterjee
Department of Chemistry and Chemical Biology, Rutgers The State University of New Jersey, Piscataway, NJ 08854 8087, USA
Mol Genet Genomics 275:264-76. 2006..Sorbitol, an osmotic stabilizer that complement defects in PKC/WSC pathways, stabilizes the mutant eIF5A and suppresses all the observed temperature-sensitive phenotypes...
- Translation elongation factor 2 anticodon mimicry domain mutants affect fidelity and diphtheria toxin resistancePedro A Ortiz
Department of Molecular Genetics, Microbiology and Immunology, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, 675 Hoes Lane, Piscataway, NJ 08854 5635, USA
J Biol Chem 281:32639-48. 2006....
- Improper organization of the actin cytoskeleton affects protein synthesis at initiationStephane R Gross
Department of Molecular Genetics, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway, NJ 08854, USA
Mol Cell Biol 27:1974-89. 2007..Our data demonstrate that eEF1A, other actin binding proteins, and actin mutants affect translation initiation through the actin cytoskeleton...