Anharmonic Bending of DNA Base-Pair Mismatch

Abstract

In vivo, mismatched base pairs introduced by erroneous replication are sharply bent by the DNA mismatch repair system, but how bending stiffness of mismatches contribute to mismatch recognition and repair efficiency is not clear. To investigate the extreme bending mechanics of mismatches, we designed a series of 105-bp dsDNA molecules, each with a single base pair mismatch in the middle, and measured their looping and unlooping rates with single-molecule Fluorescent Resonance Energy Transfer (FRET).