Base Flipping within the α-Hemolysin Latch Allows Single-Molecule Identification of Mismatches in DNA.

ABSTRACT: A method for identifying and differentiating DNA duplexes containing the mismatched base pairs CC and CA at single molecule resolution with the protein pore α-hemolysin (αHL) is presented. Unique modulating current signatures are observed for duplexes containing the CC and CA mismatches when the mismatch site in the duplex is situated in proximity to the latch constriction of αHL during DNA residence inside the pore. The frequency and current amplitude of the modulation states are dependent on the mismatch type (CC or CA) permitting easy discrimination of these mismatches from one another, and from a fully complementary duplex that exhibits no modulation. We attribute the modulating current signatures to base flipping and subsequent interaction with positively charged lysine residues at th

SUBMITTER: Johnson RP 

PROVIDER: S-EPMC4828915 | biostudies-literature | 2016 Jan

REPOSITORIES: biostudies-literature