Figure 4.

Effects of disruption of the hook:relay helix interface on DNA binding in vitro. 0.5 nM radiolabelled DNA was incubated in repair buffer with the indicated concentrations of Mfd or its derivatives for 30 min at 37°C. 2 mM ATP or ATPγS was added where shown. The complexes were analysed by running on a 5% acrylamide TAE/MgAc gel. (A) Image of a typical EMSA gel showing binding of Mfd or Mfd WA550 to a 570 bp PCR-amplified DNA fragment. (B) Images of typical EMSA gels showing binding of WT and mutant Mfd proteins to a 50 bp annealed oligonucleotide duplex. Asterisk indicates complexes of higher electrophoretic mobility observed with Mfd WA550.