Dynamics of a DNA Mismatch Site Held in Confinement Discriminate Epigenetic Modifications of Cytosine.

ABSTRACT: The identification and discrimination of four epigenetic modifications to cytosine in the proposed active demethylation cycle is demonstrated at the single-molecule level, without the need for chemical pretreatment or labeling. The wild-type protein nanopore α-hemolysin is used to capture individual DNA duplexes containing a single cytosine-cytosine mismatch. The mismatch is held at the latch constriction of α-hemolysin, which is used to monitor the kinetics of base-flipping at the mismatch site. Base-flipping and the subsequent interactions between the DNA and the protein are dramatically altered when one of the cytosine bases is replaced with methyl-, hydroxymethyl-, formyl-, or carboxylcytosine. As well as providing a route to single-molecule analysis of important epigenetic markers in

SUBMITTER: Johnson RP 

PROVIDER: S-EPMC5392251 | biostudies-literature | 2017 Feb

REPOSITORIES: biostudies-literature