ENZYMES that repair DNA may check for mutations by sending electrons along sections of the strand, in much the same way that electricians test for faults in circuits. The mechanism might explain how enzymes locate problems in the genome fast enough to correct them.
Most genetic mutations are caused by free radicals scavenging electrons from DNA. This “oxidative damage” introduces errors such as base-pair mismatches when the strand replicates. If these errors build up they can be extremely harmful.
All organisms have enzymes that can repair the errors. They bind to DNA and are thought to move slowly along the…
