title: An aminoacyl-tRNA synthetase:elongation factor complex for substrate channeling in archaeal translation.
abstract: Translation requires the specific attachment of amino acids to tRNAs by aminoacyl-tRNA synthetases (aaRSs) and the subsequent delivery of aminoacyl-tRNAs to the ribosome by elongation factor 1 alpha (EF-1alpha). Interactions between EF-1alpha and various aaRSs have been described in eukaryotes, but the role of these complexes remains unclear. To investigate possible interactions between EF-1alpha and other cellular components, a yeast two-hybrid screen was performed for the archaeon Methanothermobacter thermautotrophicus. EF-1alpha was found to form a stable complex with leucyl-tRNA synthetase (LeuRS; K(D) = 0.7 microM). Complex formation had little effect on EF-1alpha activity, but increased the k(cat) for Leu-tRNA(Leu) synthesis approximately 8-fold. In addition, EF-1alpha co-purified with the archaeal multi-synthetase complex (MSC) comprised of LeuRS, LysRS and ProRS, suggesting the existence of a larger aaRS:EF-1alpha complex in archaea. These interactions between EF-1alpha and the archaeal MSC contribute to translational fidelity both by enhancing the aminoacylation efficiencies of the three aaRSs in the complex and by coupling two stages of translation: aminoacylation of cognate tRNAs and their subsequent channeling to the ribosome.
authors.affiliation: Department of Microbiology, Ohio State Biochemistry Program, and Ohio State RNA Group, The Ohio State University, Columbus, Ohio 43210-1292, USA.
authors.forename: Corinne D
authors.initials: CD
authors.lastname: Hausmann
authors.forename: Mette
authors.initials: M
authors.lastname: Praetorius-Ibba
authors.forename: Michael
authors.initials: M
authors.lastname: Ibba
mesh_terms: D000412:Alanine-tRNA Ligase / Q000378:metabolism; D000604:Amino Acyl-tRNA Synthetases / Q000378:metabolism*; D019843:Archaeal Proteins / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000378:metabolism; D007935:Leucine-tRNA Ligase / Q000378:metabolism; D017013:Methanobacteriaceae / Q000201:enzymology / Q000235:genetics*; D020648:Peptide Elongation Factor 1 / Q000378:metabolism*; D014176:Protein Biosynthesis; D046249:Transfer RNA Aminoacylation; D020798:Two-Hybrid System Techniques
chemical_list: D019843:Archaeal Proteins; D020648:Peptide Elongation Factor 1; D006160:Guanosine Triphosphate; D000604:Amino Acyl-tRNA Synthetases; D007935:Leucine-tRNA Ligase; D000412:Alanine-tRNA Ligase