Fluorosensor proteins to detect specific DNA sequences in living bacteria

Abstract

While there are many hybridization-based DNA sensors, few of them can detect native double-stranded DNA, which is most commonly found in physiological conditions. Here we made novel fluorosensor proteins comprised of a pair of two zinc fingers tethered with an N-terminal dimerization motif and a C-terminal yellow fluorescent protein fragment (split eYFP) to detect specific DNA sequence in a living bacteria. When E. coli Top10 cells harboring the plasmid encoding the fusion proteins and a test plasmid encoding target DNA sequence were induced for the protein expression, significant increase in fluorescence was observed, compared with the strain harboring a test plasmid without target DNA sequence.