Fig. 6.
The promoter region of PA2004 was bound by His6-PA2005.EMSAs were performed with His6-PA2005 and 1.0 nM 5′-labelled Cy5 probe DNA unless specified otherwise. (a) PPA2004 (specific) or PgcvH2 (non-specific) were incubated in the absence (lanes 1 and 3, respectively) or presence (lanes 2 and 4, respectively) of 500 nM PA2005.The shift in the position of PPA2004 in lane 2 confirms that PA2005 binds to PPA2004. No shift corresponding to binding of the non-specific probe PgcvH2 by PA2005 was observed in lane 4. (b) His6-PA2005 (0 to 400 nM) was incubated with PPA2004. A shift in PPA2004 was observed for His6-PA2005 concentrations as low as 12.5 nM, indicating that His6-PA2005 binds with high affinity to PPA2004. The intensity of the shift increased with increasing His6-PA2005 concentration.