DNA scientists in Saudi Arabia have reported a breakthrough after seeing for the first time the moment our genetic code begins to copy itself.
Looking through microscopes, a team at the King Abdullah University of Science and Technology saw how our DNA “unwinds” from its spiral shape. That is a necessary step before it can be copied.
The twisted strands of the DNA double helix are “melted” by chemicals called helicases, according to the scientists. They describe them as “machines or, because of their size, nanomachines” acting inside our bodies.
Once pulled apart, other chemicals take over and get to work copying the strands of DNA. Almost every cell in the human body contains the same genetic code, which dictates things such as the colour of our eyes and hair.
Nobel Prize winners James Watson and Francis Crick discovered the double-helix structure of DNA in the 1950s – but scientists did not know, until now, how exactly it is unwound, said Alfredo De Biasio, one of the King Abdullah University scientists.
Researchers called it a milestone in the field. They said their new findings published in the journal Nature amount to the detailed description yet of the “very first steps” of DNA replication.
With their cryo-electron microscopes, scientists in Prof De Biasio's laboratory, and that of bioscientist Samir Hamdan, watched 15 atomic states unfold that reveal how the strands are split apart. They found that two of the “machines” work together to melt the DNA in one spot each.
Nanotechnology hope
The whole thing works so efficiently that it could be a model for designing miniature technology, it is hoped. That makes the study “more than an attempt to answer the most fundamental scientific questions about life”, Prof De Biasio said.
“From a design perspective, helicases exemplify energy-efficient mechanical systems,” he said. Miniature machines “could harness similar energy-efficient mechanisms to perform complex, force-driven tasks”.
He said the “machines” that prise apart our DNA are powered by a molecule called ATP. This functions “like the spring in a mouse trap, snapping the helicase forward and pulling the DNA strands apart”, he said.
Saudi Arabia launched a $200 million fund to invest in high-tech companies two years ago as part of a new strategy for King Abdullah University. The aim is to improve the chances of “turning research into economically beneficial innovations”.
The university's previous work includes a coral reef restoration on Saudi Arabia's Red Sea coast described as the world's largest, and a nanosatellite launched in 2023 to monitor the kingdom's natural resources.
