Fig. 2

DNA-PKcs has little effect on synapsis mediated by Ku plus X4L4. a Normalized synapsis efficiency mediated by different NHEJ factors −25 nM Ku, 50 nM X4L4, and 12.5 nM DNA-PKcs using the glucose plus gloxy oxygen scavenger system. Data are represented as mean ± SD of at least four independent replicates. T-test (unpaired, two-tailed) was applied for p value calculation (p = 0.08). b Histogram of E_FRET values of all synapsis events mediated by 25 nM Ku, 50 nM X4L4, and 12.5 nM DNA-PKcs using the glucose plus gloxy oxygen scavenger system in the solution. The E value shown on the distribution was obtained by a Gaussian fit of the highest peak. n = 792 molecules. c Histogram and corresponding exponential fit of total synapsis time mediated by Ku, X4L4, and DNA-PKcs using the glucose plus gloxy oxygen scavenger system in the solution. Cy3 signal lifetime (including zero-FRET and detectable FRET portions) of the synaptic complex was used to calculate the total dwell time for each synapsis event, and only the synapsis events (n = 231) with both start and end time points within the detection time window were included. Synapsis time shown on graph is represented as mean ± SD of three replicates. d Summarized dwell times of synaptic complexes formed by Ku and X4L4, and by Ku, X4L4, and DNA-PKcs using glucose plus gloxy oxygen scavenger system in the solution. Error bars represent SD of three replicates. T-test (unpaired, two-tailed) was applied for p value calculation. The corresponding dwell distributions and exponential fits are shown in c and Supplementary Fig. 3c. Source data are provided as a Source Data1 file