Single Molecular Level Study Of DNA Replication By DNA Origami

Directly imaging molecular events at the nanometre scale is important for understanding complex biological processes. Atomic force microscopy (AFM) is a powerful tool for monitoring the behaviour of individual molecules in near-physiological environments at high resolution. DNA replication plays a central role in many biological processes and is an essential factor in life. It can be exploited in various biotechnology applications. But visualising the dynamics of DNA replication will provide a deeper understanding of its mechanism.We report a DNA origami-facilitated single-molecule platform that exploits atomic force microscopy to study DNA replication. And Effect of mechanical force caused by DNA replication. The DNA origami facilitated the fixation of ssDNA to a surface, which provided a reasonable interface environment for KF enzyme activity and afforded a well-balanced platform for studying the behaviours of single molecules in real-time. We imaged several functional activities of the Klenow fragment of E. coli DNA polymerase Ⅰ (KF) including binding, moving, and dissociation from the template DNA. Upon completion of these actions, a double-stranded DNA molecule was formed. In the process of atomic force microscope scanning could impose a vertical force to the DNA strands. This force is likely to be strands of DNA and the DNA polymerase of damage. Although under small external force will changes its structure and affects function, upon period of time its structure and function can be restored or partially recovered.