Fig. 6: The nNE drives a passive follower unit.
From: A rhythmically pulsing leaf-spring DNA-origami nanoengine that drives a passive follower
a,b, Schematic of the nNE driver D (a) and the passive follower unit F (b). The structures are modified to have ssDNA overhangs protruding from the stiff origami arms. Five ssDNA overhangs (red arrows) were introduced on each arm for a total of ten unique overhangs on each origami. The sequences allow the connection of only the active structure to the passive structure. Biotin modifications (green dots) are introduced only on D. Blue circle: polymerase, orange square: HaloTag portion of HT-T7RNAP. c, Assembly of the D–F heterodimer is achieved by equimolarly combining the two parts of the system and thermal annealing overnight. d,e, After 4.5 h of transcription experiments at 37 °C the integrity of the system is confirmed by AFM (d) (scale bar, 500 nm, unprocessed scan) and TEM (e) (scale bar, 100 nm, unprocessed micrograph). f, Angle distribution from TEM images of the D–F dimer complex for samples that did not (n = 1,074, blue, 90 micrographs) and did undergo transcription (n = 1,190, orange, 87 micrographs). The distribution is plotted as bar graphs with a bin with of 3°; the count of each bar is divided by the total number of counts and displayed as the relative count percentages. g, Box-plot representation of distributions. Blue, box-plot of D–F without transcription (n = 1,074, 64.09° ± 17.32°, min = 0.00°, max = 118.96°, median = 64.73°); orange: the same with transcription (n = 1,190, 51.37° ± 17.38°, min = 4.48°, max = 104.00° median = 51.66;). ***P = 8 × 10−64. h, The transcription speed of different D–F complexes compared with the transcription speed of D alone (n = 27, 1.00 ± 0.12, min = 0.78, max = 1.22, median = 1.00). Transcription speeds: D–F ss-hinge (n = 27, 1.15 ± 0.20, min = 0.75, max = 1.52, median = 1.13; **P = 0.001), D–F soft-hinge (n = 18, 1.16 ± 0.24, min = 0.73, max = 1.60, median = 1.15; *P = 0.01); D–F complex (n = 24, 1.10 ± 0.24, min = 0.51, max = 1.48, median = 1.11; P = 0.06). P values were obtained with a two-tailed, heteroscedastic t-test. Box-plot edges, 25th and 75th percentiles; box lines, 50th percentiles; whisker size, 1.5 × IQR; grey dots, outliers; red dots, single data points. Error ranges are the mean and s.d.
