This is an artist's impression of the i-motif DNA structure inside cells, along with the antibody-based tool used to detect it. Credit: Chris Hammang
The i-motif is a four-stranded knot of DNA that is very different from a double helix, where 'letters' on opposite strands recognize each other. In the i-motif knot structure, C letters on the same strand of DNA bind to each other.
To detect the i-motifs inside cells, the researchers developed a new tool -- a fragment of an antibody molecule -- that could specifically recognize and attach to i-motifs with a very high affinity. With the new tool, researchers uncovered the location of 'i-motifs' in a range of human cell lines.
Dr Zeraati says, "We think 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."
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