New form of DNA discovered inside living human cells

An i-motif is a DNA structure that appears like a four-stranded knot in a human cell. They appear in a very small area of a genome. That pattern had been noticed before in the lab but never been seen in a human cell.

Molecular Biologist Marcel Dinger at the Garvan Institute for Medical Research in Sydney, Australia stated that i-motifs are normal in our body.

The findings were reported in Nature Chemistry on Monday.

Professor Laurence Hurley from the University of Arizona mentioned that the rare shapes of the DNA may be crucial to the human biology, and it may play a huge role in creating proteins.   

     

Not all piece of DNA can actually turn into i-motif. There is a sequence to it.

In 1900s, the French scientists found a region in a DNA strand that was rich in cytosine and has the ability to fold on top on its own, resulting in a four-stranded shape. The strand was named i-motif, where i means intercalation or a layered structure.

I-motifs only occur in areas where it is acidic, but the relevance of that four-stranded DNA is not determined yet, it may not have any impact on the genes, Dinger said.

The head of the antibody therapeutics Daniel Christ at the Garvan Institute worked together with Dinger and the others and they were able to create an antibody that can identify i-motifs in the genome and keep them together.

Biochemist Randy Wadkins at the University of Mississippi in Oxford stated that the i-motifs can be used as a switch to organize gene expression.

Wadkins questions if there is a real significance of i-motifs, and if they are beneficial to the human body. A lot of work needs to be done to find that out.