Probing Interactions within the synaptic DNA-SfiI complex by AFM force spectroscopy.

ABSTRACT: SfiI belongs to a family of restriction enzymes that function as tetramers, binding two recognition regions for the DNA cleavage reaction. The SfiI protein is an attractive and convenient model for studying synaptic complexes between DNA and proteins capable of site-specific binding. The enzymatic action of SfiI has been very well characterized. However, the properties of the complex before the cleavage reaction are not clear. We used single-molecule force spectroscopy to analyze the strength of interactions within the SfiI-DNA complex. In these experiments, the stability of the synaptic complex formed by the enzyme and two DNA duplexes was probed in a series of approach-retraction cycles. In order to do this, one duplex was tethered to the surface and the other was tethered to the probe.

SUBMITTER: Krasnoslobodtsev AV 

PROVIDER: S-EPMC1847770 | biostudies-literature | 2007 Feb

REPOSITORIES: biostudies-literature