1. Rapid and Inexpensive Evaluation of Nonstandard Amino Acid Incorporation in Escherichia coli
- Author
-
Colin W. Brown, Alejandro E. Gutierrez, Ella Watkins, Catherine Mortensen, Jeffrey E. Barrick, Nathan Y. Shin, Jordan W. Monk, Dennis M. Mishler, Sean P. Leonard, and Michael J. Hammerling
- Subjects
0301 basic medicine ,Biomedical Engineering ,Biology ,010402 general chemistry ,medicine.disease_cause ,01 natural sciences ,Biochemistry, Genetics and Molecular Biology (miscellaneous) ,Mass Spectrometry ,Amino Acyl-tRNA Synthetases ,03 medical and health sciences ,Plasmid ,RNA, Transfer ,medicine ,Escherichia coli ,Amino Acids ,Expanded genetic code ,chemistry.chemical_classification ,Translation (biology) ,General Medicine ,Genetic code ,Recombinant Proteins ,0104 chemical sciences ,Amino acid ,030104 developmental biology ,Biochemistry ,chemistry ,Genetic Code ,Protein Biosynthesis ,Transfer RNA ,Amber Stop Codon ,Plasmids - Abstract
By introducing engineered tRNA and aminoacyl-tRNA synthetase pairs into an organism, its genetic code can be expanded to incorporate nonstandard amino acids (nsAAs). The performance of these orthogonal translation systems (OTSs) varies greatly, however, with respect to the efficiency and accuracy of decoding a reassigned codon as the nsAA. To enable rapid and systematic comparisons of these critical parameters, we developed a toolkit for characterizing any Escherichia coli OTS that reassigns the amber stop codon (TAG). It assesses OTS performance by comparing how the fluorescence of strains carrying plasmids encoding a fused RFP-GFP reading frame, either with or without an intervening TAG codon, depends on the presence of the nsAA. We used this kit to (1) examine nsAA incorporation by seven different OTSs, (2) optimize nsAA concentration in growth media, (3) define the polyspecificity of an OTS, and (4) characterize evolved variants of amberless E. coli with improved growth rates.
- Published
- 2016