title: Discharging tRNAs: a tug of war between translation and detoxification in Escherichia coli.
abstract: Translation is a central cellular process and is optimized for speed and fidelity. The speed of translation of a single codon depends on the concentration of aminoacyl-tRNAs. Here, we used microarray-based approaches to analyze the charging levels of tRNAs in Escherichia coli growing at different growth rates. Strikingly, we observed a non-uniform aminoacylation of tRNAs in complex media. In contrast, in minimal medium, the level of aminoacyl-tRNAs is more uniform and rises to approximately 60%. Particularly, the charging level of tRNA(Ser), tRNA(Cys), tRNA(Thr) and tRNA(His) is below 50% in complex medium and their aminoacylation levels mirror the degree that amino acids inhibit growth when individually added to minimal medium. Serine is among the most toxic amino acids for bacteria and tRNAs(Ser) exhibit the lowest charging levels, below 10%, at high growth rate although intracellular serine concentration is plentiful. As a result some serine codons are among the most slowly translated codons. A large fraction of the serine is most likely degraded by L-serine-deaminase, which competes with the seryl-tRNA-synthetase that charges the tRNAs(Ser) These results indicate that the level of aminoacylation in complex media might be a competition between charging for translation and degradation of amino acids that inhibit growth.
authors: Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14467 Potsdam, Germany.
authors: Irem
authors: I
authors: Avcilar-Kucukgoze
authors: Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14467 Potsdam, Germany Biochemistry and Molecular Biology, University of Hamburg, Martin-Luther-King-Pl. 6, 20146 Hamburg, Germany.
authors: Alexander
authors: A
authors: Bartholomäus
authors: Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14467 Potsdam, Germany.
authors: Juan A
authors: JA
authors: Cordero Varela
authors: Bioprocess Engineering, Technical University Berlin, Ackerstr. 76, 13355 Berlin, Germany.
authors: Robert Franz-Xaver
authors: RF
authors: Kaml
authors: Bioprocess Engineering, Technical University Berlin, Ackerstr. 76, 13355 Berlin, Germany.
authors: Peter
authors: P
authors: Neubauer
authors: Biocatalysis, Technical University Berlin, Müller-Breslau-Str. 10, 10623 Berlin, Germany.
authors: Nediljko
authors: N
authors: Budisa
authors: Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14467 Potsdam, Germany Biochemistry and Molecular Biology, University of Hamburg, Martin-Luther-King-Pl. 6, 20146 Hamburg, Germany zoya.ignatova@uni-hamburg.de.
authors: Zoya
authors: Z
authors: Ignatova
mesh_terms: D000085:Acetates / Q000032:analysis; D000596:Amino Acids / Q000096:biosynthesis; D049148:Aminoacylation; D003470:Culture Media; D004926:Escherichia coli / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D008658:Inactivation, Metabolic; D014176:Protein Biosynthesis; D012343:RNA, Transfer / Q000378:metabolism*
chemical_list: D000085:Acetates; D000596:Amino Acids; D003470:Culture Media; D012343:RNA, Transfer