Thursday, June 25, 2009

A Sophisticated DNA Error Correction Mechanism

New research is adding to our knowledge of error correction mechanisms in the cell's process of protein synthesis. Proteins are created by transcribing and translating the information stored in DNA, and various error correction mechanisms maintain high levels of accuracy throughout the protein synthesis process. Indeed, these mechanisms are not only sophisticated, but they are also coordinated. As one researcher put it, "it’s almost as if cells have something akin to a computer program that becomes activated by DNA damage, and that program enables the cells to respond very quickly."

These error correction mechanisms are still not completely understood, and one puzzle is how they achieve such remarkable accuracy. The first step in the protein synthesis process is the transcription (copying) of the DNA strand, forming a new RNA strand. The RNA polymerase machine is at the heart of the process, and the new research investigates how this marvel checks for errors as it slides back and forth on the DNA strand. As one science writer explained, "Intelligent typesetters would remove the last few letters when they spot an error," and this is how the new research suggests the RNA polymerase machine corrects errors as well.