Scientists from Russia, first saw the cells of the “unwind” DNA

Ученые из России впервые увидели, как клетки "разматывают" ДНК

Russian scientists and their American colleagues have discovered how a protein works FACT, the “installation” folded DNA of cells without the expenditure of energy, which will contribute to the creation of new cancer drugs and uncovering the secrets of the origin of life on Earth, according to a paper published in the journal Nature Structural & Molecular Biology.

The total length of all DNA molecules, included in chromosomes of a human is about two meters, so our cells have to “squeeze” their strings are about 10 thousand times so that they could fit in the nucleus. For this purpose, for example, cage “spool” the DNA for a particular protein “spools”-nucleosome, the so-called proteins-the histones, which keep her strands in place and also affect their activity.

When a cell wants to consider some sort of gene, she has a partial “unwinding” of these genetic coil. The same thing happens when dividing, when the cell needs to make a copy of its DNA and pass it on to one of the daughter cells. This is a very complex process, in which the key role is played by special proteins called FACT, at the same time helping the DNA to unravel and to get lost. How it works and how much energy he spends on this operation, scientists did not know.

Kseniya Kudryashova, a fellow of the Institute of Bioorganic chemistry RAS and Lomonosov Moscow state University, and her colleagues at the Institute and scientists from the USA, learned how to work the FACT, and showed that he hardly spends it’s energy, observing the work of the protein by using new techniques of microscopy, established in Russia.

It tells Kudryashova, this technique, so-called spFRET-microscopy allows to follow the work and structure of single molecules by adding them as “tails” that glow if to illuminate them with a laser beam of a certain color. The brightness of each of the “tail” depends on where it is located, which allows to monitor changes in the structure of DNA molecules and proteins during the “unwinding” of the coils of the genetic code.

Using this technique, scientists first managed to see how the FACT spins nucleosome, while not wasting energy that came as a surprise to the biologists as other enzymes that interact with DNA, typically spend much of ATP, the cellular “Energobalance”.

It turned out that the very fact of the connection of the FACT with the “coils” of DNA was enough for the threads of the genetic code straightened themselves and not detached from the histones. Thanks to this cell gets to “count” straightened DNA and then it is not necessary to re-wind it on a protein “spool”.

The study of this process, as scientists believe, will help us understand how a similar process occurs in cancer cells, whose genes have an increased level of activity, and to understand how the work of the FACT they can be suppressed. In addition, further study of the work FACT will help scientists figure out how did this protein and what role it plays in the reproduction of healthy cells during the growth of the fetus or in the child’s body.

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