biostudies-literatureUnknownSingh ANational Institute of General Medical SciencesNIGMS NIH HHSStrand exchange between homologous nucleic acid sequences is the basis for cellular DNA repair, recombination, and genome editing technologies. Specialized enzymes catalyze cellular strand exchange; however, the reaction occurs spontaneously when a single-stranded DNA toehold can dock the invader strand on the target DNA to initiate strand exchange through branch migration. Due to its precise response, the spontaneous toehold-mediated strand displacement (TMSD) reaction is widely employed in DNA nanotechnology. However, enzyme-free TMSD suffers from slow rates, resulting in slow response times. Here, we show that human mitochondrial DNA helicase Twinkle can accelerate TMSD up to 6000-fold. Mechanistic studies indicate that Twinkle accelerates TMSD by catalyzing the docking step, which typiJournal of the American Chemical Societyhttps://www.ebi.ac.uk/biostudies/studies/S-EPMC11063129biostudies-literatureTwinkle-Catalyzed Toehold-Mediated DNA Strand Displacement Reaction.PMC11063129GM118086R35 GM118086Singh APatel GPatel SSfalseTwinkle-Catalyzed Toehold-Mediated DNA Strand Displacement Reaction.Strand exchange between homologous nucleic acid sequences is the basis for cellular DNA repair, recombination, and genome editing technologies. Specialized enzymes catalyze cellular strand exchange; however, the reaction occurs spontaneously when a single-stranded DNA toehold can dock the invader strand on the target DNA to initiate strand exchange through branch migration. Due to its precise response, the spontaneous toehold-mediated strand displacement (TMSD) reaction is widely employed in DNA nanotechnology. However, enzyme-free TMSD suffers from slow rates, resulting in slow response times. Here, we show that human mitochondrial DNA helicase Twinkle can accelerate TMSD up to 6000-fold. Mechanistic studies indicate that Twinkle accelerates TMSD by catalyzing the docking step, which typi2023-01-01T00:00:00Z2023 Nov2025-07-13T03:04:35.878Z2025-07-13T03:04:35.878ZS-EPMC110631293791793010.1021/jacs.3c04970