[extropy-chat] Optical Force Clamps Allow Observation Of Single RNA Polymerase Enzyme

[Giu1i0 Pri5c0]

>From FuturePundit: Steven M. Block, a professor of biological sciences and
of applied physics at Stanford University, and his team have developed
two-dimensional optical force clamps that can monitor the action of a single
RNA polymerase (RNAP) enzyme.
In a new study in the journal Nature, Block and his colleagues present
strong evidence to support this proofreading hypothesis. Their results --
based on actual observations of individual molecules of RNAP -- are posted
on Nature's website: http://www.nature.com. In another set of experiments
published in the Nov. 14 issue of Cell magazine, the researchers discovered
that RNAP makes thousands of brief pauses as it pries open and copies the
DNA double helix.
"Together these two papers push the study of single proteins to new limits,"
Block said. "We've been able to achieve a resolution of three angstroms --
the width of three hydrogen atoms -- in our measurements of the progress of
this enzyme along DNA. In so doing, we've been able to visualize a
backtracking motion of just five bases that accompanies RNAP
error-correction or proofreading."
This is an example of why the rate of advance in biological science is not
constant. The development of instrumentation that can study components of
biological systems down on the scale at which they operate will allow these
systems to be figured out orders of magnitude more quickly. The biggest
reason we still know only a small fraction of what there is to understand
about cells and diseases is that we can't watch what happens down at the
level at which events actually take place. Continued advances in the ability
to build smaller devices and smaller sensors will make observable that which
it has previously never been possible to observe.
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