Though DNA inside cells gets regularly damaged, errors are typically quickly reset by a still poorly understood molecular mechanism. It has been suspected that repair enzymes actually walk the length of the DNA molecule fixing errors along the way. But the number of base pairs within each gene can be a million long, necessitating a smarter, more selective approach. Now researchers at University of North Texas discovered that exons (parts of genes that carry information) and introns (parts that do not) have different electrical properties, which may allow repair enzymes to skip long strings that do not code for anything.
The Physics arXiv Blog explains:
The group has calculated from first principles the way in which charge flows in different regions. They say that in exons–the information carrying parts of genes–the energy spectrum of the molecule allows delocalised electrons to exist. In these areas, charge can flow.
However the energy spectrum of the regions that do not carry information–the introns–does not allow for delocalised electrons. So introns are effectively insulators.
That sets up well defined regions within DNA that can be identified electronically.It also means that any change in electronic properties caused by a mutation would be largely confined too. That immediately suggests a way that repair enzymes can home in on damage.
More from The Physics arXiv Blog…
Abstract in arXiv: Inhomogeneous DNA: conducting exons and insulating introns