Scientists have confirmed the new DNA structure
The new findings, which come from the Garvan Institute of Medical Research and were published in the journal „Nature Chemistry”.
All life on Earth is built on the same foundations. In a nutshell, they are formed by four nitrogenous bases that form nucleotides, ktore are the building blocks of DNA. Two purine – adenine and guanine and two pyrimidine – cytosine and thymine. Each of these substances, for ease of reference, is denoted by a single letter. Thus, respectively, A – is the adenine, T – thymine, C – cytosine and G, whichor by guanine.
These principles in a unique combination for each organism contain its genetic record. This information contains precise instructions on how our bodies are built and how they function. The symbolic shape of the suboThe DNA helix captured the public imagination in 1953, when James Watson, Francis Crick and Rosalinda Franklin discovered the structure of the DNA.
However, it is now known that krotic segments of DNA could exist in other shapes, at least in the lab – and scientists suspect that these roThe different shapes may play an important role in how and when the DNA code is "read".
New shape – „node” i-motfi – looks very different from subojna helix of DNA. – When most of us think of DNA, we think of subojnej helix,” said Professor Daniel Christ, a wsporesearch royale. – New research reminds us that completely different DNA structures exist – and may be important to our comorec – added.
Although scientists have already seen i-motif and specificolarly they studied it, it was only observed under artificial conditions in the lab, not in the comorks of the body. Researchers have even argued whether this structure in ogole exists in living beings. Spor this has been solved by new discoveries.
Scientists used a modified immune system molecule in their study, whichora was able to recognize non-helix DNA structures. With this, the i-motif was located, and using fluorescence techniques, the position of these structures was pinpointed, whichore appeared during imaging as green spots.
– What excited us most is that we see green spots – i-motifs – appearing and disappearing over time, so we know that they form, dissolve and form again – explained Mahdi Zeraati.
Scientists have shown that i-motif structures are formed most often at a specific point in the "life cycle" comorki – poźn the early G1 phase, when DNA is actively "read". They also showed that these structures appear in someorych promoter regions of the gene (areas of DNA thatore control whether genes are turned on or off) and at telomeres, the terminal sections of the chromosomeoin whichore are important in the aging process.
– It seems to us that these structures are there to turn genes on or off and influence whether a gene is actively read or not – Zeraati estimated. – The transient nature of these structures also explains why they have been so difficult to find until now – emphasized, in turn, Christ.