Direct and random routing of a molecular motor protein at a DNA junction.

With the aim of investigating how motor proteins negotiate DNA nanostructures, we produced test circuits based on recombination intermediates in which 1D translocation across a Holliday junction (HJ) could be assessed by subsequent triplex displacement signals on each DNA arm. Using the EcoR124I restriction-modification enzyme, a 3'-5' double-strand DNA (dsDNA) translocase, we could show that the motor will tend to follow its translocated strand across a junction. Nonetheless, as the frequency of junction bypass events increases, the motor will occasionally jump tracks.