title: Genetic code translation displays a linear trade-off between efficiency and accuracy of tRNA selection.
abstract: Rapid and accurate translation of the genetic code into protein is fundamental to life. Yet due to lack of a suitable assay, little is known about the accuracy-determining parameters and their correlation with translational speed. Here, we develop such an assay, based on Mg(2+) concentration changes, to determine maximal accuracy limits for a complete set of single-mismatch codon-anticodon interactions. We found a simple, linear trade-off between efficiency of cognate codon reading and accuracy of tRNA selection. The maximal accuracy was highest for the second codon position and lowest for the third. The results rationalize the existence of proofreading in code reading and have implications for the understanding of tRNA modifications, as well as of translation error-modulating ribosomal mutations and antibiotics. Finally, the results bridge the gap between in vivo and in vitro translation and allow us to calibrate our test tube conditions to represent the environment inside the living cell.
authors.affiliation: Department of Cell and Molecular Biology, Biomedical Center, Uppsala University, Box 596, 751 24 Uppsala, Sweden.
authors.forename: Magnus
authors.initials: M
authors.lastname: Johansson
authors.forename: Jingji
authors.initials: J
authors.lastname: Zhang
authors.forename: Måns
authors.initials: M
authors.lastname: Ehrenberg
mesh_terms: D001483:Base Sequence; D003062:Codon / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics; D005815:Genetic Code / Q000235:genetics*; D006160:Guanosine Triphosphate / Q000378:metabolism; D006868:Hydrolysis / Q000187:drug effects; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D014176:Protein Biosynthesis / Q000187:drug effects; D012343:RNA, Transfer / Q000235:genetics*; D012270:Ribosomes / Q000187:drug effects / Q000378:metabolism; D012641:Selection, Genetic
chemical_list: D003062:Codon; D006160:Guanosine Triphosphate; D012343:RNA, Transfer; D008274:Magnesium