Effect of spermine NONOate on DNA-binding activity of NsrR. The nasD (−114 to −4) probe was incubated with RNAP (15 nM), ResD∼P (0.5 μM), and anaerobically purified NsrR-His6 (128 nM) (A), or with RNAP and NsrR-His6 (B) in the absence or presence of increasing concentrations of SperNO. Full arrows and broken arrows show the nasD-NsrR complex formed in the absence and presence of SperNO, respectively. A single asterisk shows the free probe.
C. The nasD probe was incubated with either anaerobically or aerobically purified NsrR-His6 in the absence or presence of SperNO. The free probe ran off the gel. All EMSA reactions and electrophoresis were carried out in an anaerobic chamber.