Tripling up DNA

We are familiar with the DNA double helix, less familiar is the entity that arises when three strands intertwine. However, a team at the Institute for Research in Biomedicine (IRB Barcelona) and the Barcelona Supercomputing Center (BSC) have obtained structural information for a triple helix DNA in a near-vacuum gas phase. "Until now these special DNA structures were almost impossible to detect," explains team leader Modesto Orozco. "We have characterized this structure and demonstrated that it maintains a surprising memory of its previous biological environment, aqueous solution, in which it is normally very difficult to characterize." The research could pave the way to developing antigen therapy in which triple-helical DNA is used to switch of genes in a particular disease state. The technique also shows how X-ray free-electron lasers are set to become powerful new tools for structural science.