Endonucleases and DNA Fragments
A restriction endonuclease functions by "scanning" the length of a DNA molecule. Once it encounters its particular specific recognition sequence, it will bind to the DNA molecule and makes one cut in each of the two sugar-phosphate backbones. The positions of these two cuts, both in relation to each other, and to the recognition sequence itself, are determined by the identity of the restriction endonuclease used to cleave the molecule in the first place. Different endonucleases yield different sets of cuts, but one endonuclease will always cut a particular base sequence the same way, no matter what DNA molecule it is acting on. Once the cuts have been made, the DNA molecule will break into fragments.
Read more about this topic: Nuclease
Famous quotes containing the words dna and/or fragments:
“Here [in London, history] ... seemed the very fabric of things, as if the city were a single growth of stone and brick, uncounted strata of message and meaning, age upon age, generated over the centuries to the dictates of some now all-but-unreadable DNA of commerce and empire.”
—William Gibson (b. 1948)
“The vast results obtained by Science are won by no mystical faculties, by no mental processes other than those which are practiced by every one of us, in the humblest and meanest affairs of life. A detective policeman discovers a burglar from the marks made by his shoe, by a mental process identical with that by which Cuvier restored the extinct animals of Montmartre from fragments of their bones.”
—Thomas Henry Huxley (1825–95)