02 May A New DNA Structure Inside Human Cells Has Been Discovered
When most of us think of DNA, we think of the double helix, BUT it’s not just the double helix!
If your only familiarity with DNA shapes is the dual helical spirals made famous by Watson and Crick, the configuration of the new motif could come as a surprise. For the first time, scientists have identified the existence of a new DNA structure never before seen in living cells.
The discovery of what’s described as a ‘twisted knot’ of DNA in living cells confirms our complex genetic code is crafted with more intricate symmetry than just the double helix structure everybody associates with DNA – and the forms these molecular variants take affect how our biology functions.
The new DNA component the team identified is called the intercalated motif (i-motif) structure, which was first discovered by researchers in the 1990s, but up until now had only ever been witnessed in vitro, not in living cells.
Now, thanks to Christ’s team, we know the i-motif occurs naturally in human cells, meaning the structure’s significance to cell biology – which has previously been called into question, given it had only been demonstrated in the lab – demands new attention from researchers.
The i-motif is a four-stranded ‘knot’ of DNA.
Scientists highlighted the location of ‘knots’ in the cell with an immunofluorescent glow. The i-motifs are appearing and disappearing over time in the cell, which confirms that they are forming, dissolving and forming again. Scientist believe that the coming and going of the i-motifs is a clue to what they do. It seems likely that they are there to help switch genes on or off, and to affect whether a gene is actively read or not.
Now that we definitively know this new form of DNA exists in cells, it’ll give researchers a mandate to figure out just what these structures are doing inside our bodies.
“Therefore, the formation of these structures might be of utmost importance for the cell to function normally. And, any aberration in these structures might have pathological consequences.”
The findings are reported in Nature Chemistry.