Fig. 2.

IflA is a four-color-sensing CBCR. (A) PCB-producing E. coli cell pellets containing wild-type and cysteine mutant forms of IflA608, GAF1, and GAF3. (B) Zn²⁺ blots (Upper) and stained bands (Lower) of wild-type and cysteine mutants of purified IflA608, GAF1, and GAF3. Upper and lower image sets were each spliced together from nonadjacent lanes of the same blot or gel. (C–H) Absorption spectra of purified wild-type and select cysteine mutants of IflA608, GAF1, and GAF3. Line colors indicate the blue, green, red, and far-red light treatment provided to that sample before scanning. Spectral distributions of the light sources are provided in Fig. S2C. Difference spectra for green minus blue (green lines) and red minus far red (red lines) treatments are shown (Insets).