Extended Data Fig. 3: BLADE is dimeric under light and contacts the I2 DNA half-site.
From: Engineering AraC to make it responsive to light instead of arabinose
a, Absorption spectra measured with the protein incubated 1 day (left) or 4 days (right) in the dark at 4 °C (black) or illuminated with blue light (455 nm; 50 W/m2) for 5 min at room temperature (cyan). The absorption spectrum of the blank (only medium) was subtracted from the dark and lit state spectra. b, SEC performed with purified BLADE in the dark or illuminated with 460 nm light (5 W/m2) for 30 min at 4 °C. c, Schematic representation of the synthetic promoter with the inverted I2 half-site. d, MG1655 cells transformed with pBLADE_I2 rev-mCherry grown 4h either in the dark or under 460 nm light (5 W/m2) illumination were analyzed by flow cytometry. The values were normalized to the mCherry fluorescence intensity measured in cells transformed with pReporter_only (see Supplementary Table 1; dashed line). Values represent mean ± SD of n = 3 independent experiments. The individual data points are the mean values of 10,000 single-cell flow cytometry events. Not significant (ns), P < 0.05. The P-value P was calculated by the two-tailed, homoscedastic Student’s t-test.
