Association between Archaeal prolyl- and leucyl-tRNA synthetases enhances tRNA(Pro) aminoacylation.

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TitleAssociation between Archaeal prolyl- and leucyl-tRNA synthetases enhances tRNA(Pro) aminoacylation.
Publication TypeJournal Article
Year of Publication2005
AuthorsPraetorius-Ibba, M, Rogers, TE, Samson, R, Kelman, Z, Ibba, M
JournalJ Biol Chem
Date Published2005 Jul 15
KeywordsAmino Acyl-tRNA Synthetases, Chromatography, Chromatography, Gel, DNA, Complementary, Electrophoresis, Polyacrylamide Gel, Escherichia coli, Gene Library, Histidine, Kinetics, Leucine-tRNA Ligase, Methanobacteriaceae, Phenotype, Protein Binding, Protein Biosynthesis, RNA, Messenger, RNA, Transfer, Pro, Temperature, Two-Hybrid System Techniques

Aminoacyl-tRNA synthetase-containing complexes have been identified in different eukaryotes, and their existence has also been suggested in some Archaea. To investigate interactions involving aminoacyl-tRNA synthetases in Archaea, we undertook a yeast two-hybrid screen for interactions between Methanothermobacter thermautotrophicus proteins using prolyl-tRNA synthetase (ProRS) as the bait. Interacting proteins identified included components of methanogenesis, protein-modifying factors, and leucyl-tRNA synthetase (LeuRS). The association of ProRS with LeuRS was confirmed in vitro by native gel electrophoresis and size exclusion chromatography. Determination of the steady-state kinetics of tRNA(Pro) charging showed that the catalytic efficiency (k(cat)/K(m)) of ProRS increased 5-fold in the complex with LeuRS compared with the free enzyme, whereas the K(m) for proline was unchanged. No significant changes in the steady-state kinetics of LeuRS aminoacylation were observed upon the addition of ProRS. These findings indicate that ProRS and LeuRS associate in M. thermautotrophicus and suggest that this interaction contributes to translational fidelity by enhancing tRNA aminoacylation by ProRS.

Alternate JournalJ. Biol. Chem.
PubMed ID15917221
PubMed Central IDPMC1242193
Grant ListGM 65183 / GM / NIGMS NIH HHS / United States
R01 GM065183-03 / GM / NIGMS NIH HHS / United States