Document Type
Article
Publication Date
12-11-2006
Abstract
Aminoacyl-tRNA synthetases (aaRSs) are responsible for attaching amino acids to their cognate tRNAs during protein synthesis. In eukaryotes aaRSs are commonly found in multi-enzyme complexes, although the role of these complexes is still not completely clear. Associations between aaRSs have also been reported in archaea, including a complex between prolyl-(ProRS) and leucyl-tRNA synthetases (LeuRS) in Methanothermobacter thermautotrophicus that enhances tRNAPro aminoacylation. Yeast two-hybrid screens suggested that lysyl-tRNA synthetase (LysRS) also associates with LeuRS in M. thermautotrophicus. Co-purification experiments confirmed that LeuRS, LysRS, and ProRS associate in cell-free extracts. LeuRS bound LysRS and ProRS with a comparable KD of about 0.3–0.9 μm, further supporting the formation of a stable multi-synthetase complex. The steady-state kinetics of aminoacylation by LysRS indicated that LeuRS specifically reduced the Km for tRNALys over 3-fold, with no additional change seen upon the addition of ProRS. No significant changes in aminoacylation by LeuRS or ProRS were observed upon the addition of LysRS. These findings, together with earlier data, indicate the existence of a functional complex of three aminoacyl-tRNA synthetases in archaea in which LeuRS improves the catalytic efficiency of tRNA aminoacylation by both LysRS and ProRS.
Recommended Citation
Prætorius-Ibba, M., Hausmann, C., Paras, M., Rogers, T.E. and Ibba, M. (2007) Functional association between three archaeal aminoacyl-tRNA synthetases. J. Biol. Chem 282, 3680-3687. https://doi.org/10.1074/jbc.M609988200
Copyright
American Society for Biochemistry and Molecular Biology
Included in
Amino Acids, Peptides, and Proteins Commons, Biochemistry Commons, Cellular and Molecular Physiology Commons, Molecular Biology Commons, Nucleic Acids, Nucleotides, and Nucleosides Commons, Other Biochemistry, Biophysics, and Structural Biology Commons
Comments
This article was originally published in Journal of Biological Chemistry, volume 282, in 2007. https://doi.org/10.1074/jbc.M609988200