Fast-scan atomic force microscopy reveals that the type III restriction enzyme EcoP15I is capable of DNA translocation and looping.

ABSTRACT: Many DNA-modifying enzymes act in a manner that requires communication between two noncontiguous DNA sites. These sites can be brought into contact either by a diffusion-mediated chance interaction between enzymes bound at the two sites, or by active translocation of the intervening DNA by a site-bound enzyme. EcoP15I, a type III restriction enzyme, needs to interact with two recognition sites separated by up to 3,500 bp before it can cleave DNA. Here, we have studied the behavior of EcoP15I, using a novel fast-scan atomic force microscope, which uses a miniaturized cantilever and scan stage to reduce the mechanical response time of the cantilever and to prevent the onset of resonant motion at high scan speeds. With this instrument, we were able to achieve scan rates of up to 10 frames per

SUBMITTER: Crampton N 

PROVIDER: S-EPMC1937539 | biostudies-literature | 2007 Jul

REPOSITORIES: biostudies-literature