Analysis of NurA/HerA complex activity.

<p>(A) HerA DNA helicase activity has been tested on a forked DNA using 12 pmoles of HerA in the absence (lane 3) or in the presence of two different concentrations of NurA, 11 and 20 pmoles (lanes 6–7). NurA was also analyzed without HerA (lanes 4–5) as control. The single-stranded DNA (lane 1) was loaded to visualize its migration, while the forked substrate has been loaded on lane 2. (B) The endonuclease activity of NurA/HerA complex was tested on a circular double-stranded DNA. The two proteins were analyzed separately using 18 pmoles of NurA or 18 pmoles of HerA (lanes 2 and 3, respectively) or together using increasing concentration of HerA from 0.8 to 18 pmoles (lanes 4–7). A control lane in which no protein was added was loaded on lane 1. (C) Nuclease activity of NurA/HerA complex on a linear double-stranded DNA (2000 bp). The two proteins were analyzed separately using 4.7 pmoles of NurA or 3 pmoles of HerA (lanes 2 and 3, respectively) or together using increasing amounts of NurA from 0.4 to 4.7 pmoles and a fixed concentration of HerA (3 pmoles) (lanes 4–8). A control lane in which no protein was added was loaded on lane 1.