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.
�The microscope and new techniques give us a clear view of the
molecular interactions between proteins and DNA that we could only
previously interpret indirectly. The indirect methods require
scientists to make assumptions to interpret their data, and video
footage like this can help to provide a more direct understanding of
what is really happening.
�Standard technology for filming on this scale can only produce one
image frame every 8 minutes. However, our new work allows one frame
per 500 � or fewer, milliseconds.�
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. However, this could also
provide a model for understanding how other enzymes and DNA, in any
type of organism, including humans, interact.
�This helps us understand how enzymes recognise which bit of a DNA
strand to latch onto, which is important in understanding how proteins
repair damaged DNA. In the long term, this could help in the search
for cancer treatments, as cancer sometimes occurs where DNA is damaged
but enzymes do not behave correctly in order to repair it.�
Steve Visscher, interim BBSRC Chief Executive, said: �BBSRC strongly
supports the development of new tools and resources and this study
clearly highlights the significance of cutting-edge technologies to
bioscience research. It is essential that bioscientists can draw upon
technologies from the physical and engineering sciences to improve
their understanding of biological processes.�
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