Thursday, September 20, 2007

Video of Enzyme Unraveling DNA

For the first time, scientists have videotaped the interaction of an enzyme and DNA. Researchers from the University of Cambridge have used a revolutionary Scanning Atomic Force Microscope in Japan to produce amazing footage of a protective enzyme unraveling the DNA of a virus trying to infect a bacterial host. The footage shows a bacterial type III restriction enzyme attaching itself to the DNA of a virus, in order to break the DNA before the virus has the chance to infect the bacterium.
Dr Robert Henderson, who led the Cambridge research, explains:

“This is the first time that such a process has been seen in real time. To be able see these nano-mechanisms as they are really happening is incredibly exciting. We can actually see the enzyme ‘threading’ through a loop in the virus’s DNA in order to lock on to and break it, a process known as DNA cleavage."

This film was originally published online on July 23, 2007 in the journal The Proceedings of the National Academy of Sciences (PNAS), 10.1073/pnas.0700483104

Original press release here.


  1. I feel a little stupid asking this question, but I can't really understand what I am seeing. Which molecule is the enzyme and are the two long stringy things (top and bottom) the DNA?

  2. The "two long stringy things" are definitely DNA. I had assumed the white blob was the enzyme, but on closer look, I'm no longer sure.

  3. I assumed that the white blob was the enzyme too.