FIGURE 6.

EPR spectra of wild-type and mutant QhpD complexes with sQhpC or sQhpC^C7S. The X-band EPR spectra of the reconstituted sQhpC·QhpD, sQhpC^C7S·QhpD, sQhpC·QhpD^C116S, sQhpC·QhpD^C353S, sQhpC·QhpD^G161A, and sQhpC·QhpD^R373A complexes (80 μm) are shown with important g values including those for g_‖ and g_⊥ signals. X-band (9.23 GHz) microwave frequency spectra before (gray) and after (black) the addition of 2 mm DT were recorded at 15 K with modulation frequency, 100 kHz; modulation amplitude, 1 millitesla (mT); and microwave power, 10 milliwatts.