Few people know that besides the classic double helix, opened in 1953, DNA can take other forms. The discoverers of DNA, Watson and Crick were not informed about this, because I was not sure that these are real molecules, not just garbage, scraps of larger chains. More recently, however, medical research Institute Garvan created a tool that allowed to get to the truth. For example, it is well established that there is DNA in the form of a node. But what is its role?
Encoding information about the structure of a living organism in DNA is not only a unique sequence of nucleotides but also the shape of the molecule. From the shape of the chain depends on how it contacts with RNA, as will “read” the recorded information in it. And from this point of view, the structure of the “i-motif”, the node of the four chains of nucleotides, raises many questions. Here the C nucleotides in one chain are linked to each other, whereas in the spiral they always interact with the nucleotide G and then only on the opposite chain.
If the DNA exists stably, then the i-motif has the ability to disappear and reappear again. Australian scientists have created a fragment of the antibody molecules that can only interact with i-motif and in contact triggers a reaction of fluorescence. Further, by studying the order of appearance of green spots on the test environment, they began to study the patterns. It is believed that the i-motif are activated at key moments in the life of DNA can “turn on” and “off” individual genes.
It has been proved that the nodal DNA found in telomeres, the protective “caps” at the ends of chromosomes, which play a major role in biological aging. And are active during the last phase of the life cycle of the cell, during the reading of DNA to create new cells. But what exactly makes i-motif, scientists still can not answer – they find themselves on the verge of discovery, but research is still far from complete.
Source Garvan Institute of Medical Research