Jerusalem, April 6
Israeli researchers discovered a mechanism responsible for the rapid repair of broken DNA, the northern Israel Institute of Technology, or Technion, said.
The discovery, included in a new study published in the journal Nature Communications, may have implications for DNA repair in human cells and for understanding disorders in various disease states, the Technion said on Tuesday.
The genome, essential for all organisms, is threatened by many external and internal factors, which cause thousands of DNA damage events in each cell every day, Xinhua news agency reported.
Some damages could be so severe as to cause harmful mutations and cell death. So during evolution, the living cell developed sophisticated repair mechanisms for dangerous breaks.
In bacteria, the repair is initiated by the enzyme RecBCD, which forms the pair of bases that make up the double helix of DNA in the area of damage.
The energy for this process is extracted by the enzyme from ATP molecules, which carry the cell's energy.
In this process, more than 1,600 base pairs are unwinded in a second, which is a tremendous speed in biological terms. To reach this speed, RecBCD needs thousands of ATP molecules per second.
The Technion researchers found the existence of auxiliary binding sites in RecBCD, which allow the high speed.
"RecBCD achieves its optimised unwinding rate, even when ATP is scarce, by using the auxiliary binding sites to increase the flux of ATP to the required locations," the researchers explained.
The binding sites create a "funnel" for ATP molecules, which channels the "fuel" toward the two "engines" of RecBCD efficiently and quickly, according to Technion.