DNA helicase activity of Rep68 and TrwC/Rep.

Increasing amounts of Rep68 and TrwC/Rep chimeric protein (0, 1, 10, 100 ng of protein) were assayed in the presence or absence of ATP. “boil” indicates heat-denatured substrate, used as a positive control. Products of the reaction were resolved on 12% native polyacrylamide gels. The diagram to the left of the gel shows the position of the substrate (partial duplex M13 DNA) and unwound labelled ssDNA. The percent of unwound substrate was quantified using the Image Quant TL software. The helicase efficiency percentage is a representative example obtained from 3 independent experiments (n = 3).