FIGURE 5.
DNA bending measurements of promoter and non-promoter DNAs by FRET. Donor-acceptor doubly labeled DNA (20 nm) was titrated with Mtf1 (blank circle), Rpo41 (red triangle), or a mixture of Rpo41+Mtf1 (1:1.2) (black filled circle), or titrated with Mtf1 following Rpo41 saturation (green square). EFRET was calculated at each point as described under “Experimental Procedures.” A, FRET measurements on −12/+8-mt20. B, FRET measurements on RD-ds20. C, FRET measurements on promoter mutant −2C:G-mt20. D, FRET efficiencies of free DNA (black bars) and in a complex with Rpo41 (red bars) or Rpo41-Mtf1 (green bars). The yellow bars show the FRET efficiencies at the highest protein concentration used. Standard errors from multiple measurements are shown. Error bars show the standard deviation for −12/+8-mt20 and RD-mt20 from multiple independent experiments or the range from two measurements for other DNA constructs.