Visual analysis of concerted cleavage by type IIF restriction enzyme SfiI in subsecond time region.

ABSTRACT: Many DNA regulatory factors require communication between distantly separated DNA sites for their activity. The type IIF restriction enzyme SfiI is often used as a model system of site communication. Here, we used fast-scanning atomic force microscopy to monitor the DNA cleavage process with SfiI and the changes in the single SfiI-DNA complex in the presence of either Mg²⁺ or Ca²⁺ at a scan rate of 1-2 fps. The increased time resolution allowed us to visualize the concerted cleavage of the protein at two cognate sites. The four termini generated by the cleavage were released in a multistep manner. The high temporal resolution enabled us to visualize the translocation of a DNA strand on a looped complex and intersegmental transfer of the SfiI protein in which swapping of the site is perform

SUBMITTER: Suzuki Y 

PROVIDER: S-EPMC3244053 | biostudies-literature | 2011 Dec

REPOSITORIES: biostudies-literature