The Fitness Effects of Codon Composition of the Horizontally Transferred Antibiotic Resistance Genes Intensify at Sub-lethal Antibiotic Levels.

The rampant variability in codon bias existing between bacterial genomes is expected to interfere with horizontal gene transfer (HGT), a phenomenon that drives bacterial adaptation. However, delineating the constraints imposed by codon bias on functional integration of the transferred genes is complicated by multiple genomic and functional barriers controlling HGT, and by the dependence of the evolutionary outcomes of HGT on the host's environment. Here, we designed an experimental system in which codon composition of the transferred genes is the only variable triggering fitness change of the host.

Simplified methodology for a modular and genetically expanded protein synthesis in cell-free systems.

Genetic code expansion, which enables the site-specific incorporation of unnatural amino acids into proteins, has emerged as a new and powerful tool for protein engineering. Currently, it is mainly utilized inside living cells for a myriad of applications. However, the utilization of this technology in a cell-free, reconstituted platform has several advantages over living systems.