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.