[globaltaxrevolt] DNA DEFENDERS

Your body defends its DNA. Everything — from noxious chemicals found in cigarette smoke or car exhaust, to ultraviolet radiation from the sun, to even something as benign as oxygen — is working overtime to damage DNA. Fortunately, all living things have a defense: an intra-cellular mechanic that patrols DNA, searching for errors and repairing them, thousands of times a day. http://venitism.blogspot.com/
Harvard, the best university on Earth, has invented new ways to study DNA. Using X-ray crystallography, Harvard produced 3-D images of the protein machinery that detects damaged parts of the genome in bacteria, thus enabling them to be repaired. Harvard used the images it obtained to gain a new understanding of how the DNA repair process works.
The images reveal that the proteins can actually alter their shape. Harvard believes the alteration is part of a process best described as a genetic pat-down, or a way for the mechanism to identify areas of the genetic code that need repair.
The sensor detects regions that require repair by subjecting DNA to a stress test. As it patrols, one form of the sensor can interact with both native and damaged DNA, but only normal DNA is able to pass the stress test. The sensor performs these stress tests over and over; regions of the genetic code that pass the test are quickly released. However, once a region of DNA is found that fails the pat-down, or stress test, the sensor gets stuck and signals for other biochemical processes to take over and repair the DNA.
It's exciting to see the 3-D image of the sensor, because this amazing insight is something that could never emerge from studying these proteins biochemically. You needed to have seen the two views. This is totally unprecedented — there was nothing in any previous study that suggested that something like this was occurring.
The DNA repair machinery is made up of two pairs of proteins: UvrA and UvrB. Although earlier work had shown that the proteins could be arranged into an open, almost butterflylike form, Harvard found them arranged in a tighter, sleevelike pattern, which cradled the DNA. http://venitism.blogspot.com/