title: Development of potent in vivo mutagenesis plasmids with broad mutational spectra.
abstract: Methods to enhance random mutagenesis in cells offer advantages over in vitro mutagenesis, but current in vivo methods suffer from a lack of control, genomic instability, low efficiency and narrow mutational spectra. Using a mechanism-driven approach, we created a potent, inducible, broad-spectrum and vector-based mutagenesis system in E. coli that enhances mutation 322,000-fold over basal levels, surpassing the mutational efficiency and spectra of widely used in vivo and in vitro methods. We demonstrate that this system can be used to evolve antibiotic resistance in wild-type E. coli in <24 h, outperforming chemical mutagens, ultraviolet light and the mutator strain XL1-Red under similar conditions. This system also enables the continuous evolution of T7 RNA polymerase variants capable of initiating transcription using the T3 promoter in <10 h. Our findings enable broad-spectrum mutagenesis of chromosomes, episomes and viruses in vivo, and are applicable to both bacterial and bacteriophage-mediated laboratory evolution platforms.
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA.|Howard Hughes Medical Institute, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Ahmed H
authors.initials: AH
authors.lastname: Badran
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA.|Howard Hughes Medical Institute, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: David R
authors.initials: DR
authors.lastname: Liu
mesh_terms: D017903:Bacteriophage T3 / Q000235:genetics; D012321:DNA-Directed RNA Polymerases / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000235:genetics*; D005818:Genetic Engineering / Q000379:methods; D005821:Genetic Techniques; D005822:Genetic Vectors; D059014:High-Throughput Nucleotide Sequencing; D007763:Lac Operon / Q000235:genetics; D016296:Mutagenesis / Q000235:genetics*; D009154:Mutation; D010957:Plasmids / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics; D014764:Viral Proteins / Q000235:genetics
chemical_list: D029968:Escherichia coli Proteins; D014764:Viral Proteins; C540081:rpoB protein, E coli; C062210:bacteriophage T7 RNA polymerase; D012321:DNA-Directed RNA Polymerases