Anticooperative Binding Governs the Mechanics of Ethidium-Complexed DNA.

ABSTRACT: DNA intercalators bind nucleic acids by stacking between adjacent basepairs. This causes a considerable elongation of the DNA backbone as well as untwisting of the double helix. In the past few years, single-molecule mechanical experiments have become a common tool to characterize these deformations and to quantify important parameters of the intercalation process. Parameter extraction typically relies on the neighbor-exclusion model, in which a bound intercalator prevents intercalation into adjacent sites. Here, we challenge the neighbor-exclusion model by carefully quantifying and modeling the force-extension and twisting behavior of single ethidium-complexed DNA molecules. We show that only an anticooperative ethidium binding that allows for a disfavored but nonetheless possible interca

SUBMITTER: Dikic J 

PROVIDER: S-EPMC6486475 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature