Unfortunately there were not many responses to my question if I should report on a recent paper in which I am co-author, here. The poll in the sidebar is clicked exactly 1 time. Since the result but now at 100% for the explanation is, I will continue to do so. Only I will, as Caesar wrote in the comment section, to forgo a research setting at blogging. Their policy does not writing their own papers, but still seems not to be acceptable.
As used in the paper several points to language that can stand on their own legs, I will divide the discussion of the paper. So that is not a mega post, and I can each respond better to the background.
Today I begin the short paper for the relevant genes and their protein products to imagine that everyone has an idea about their function in the cell. Central here is a complex of three proteins, have on their own entirely different biochemical properties.
About the family of RecQ helicases I've written very little, although I am concerned since my graduate work with them. From the Biounterricht some may remember the term for a helicase protein that is required for the copying of DNA (replication). Since the two strands of DNA are stored together, it can be copied only when the base pairings were released. This is achieved by a group of proteins called helicases, which make in energy consumption of a double strand two single strands. After that then start the merry-copy DNA. Helicases but are used not only during replication - most events at the DNA need the help of a helicase, which is why it is of the human genome also according to the UniProt protein database over 150 . Attention has been paid a little more intense with the metabolism of DNA, then it is almost inevitably a family of helicases (ie a group of proteins whose genes are evolutionarily related and all of a single gene have a common ancestor), the RecQ helicases. This is because members of this family of various tasks in the preservation of DNA, as we know it have the following: They are active in recombination and repair of DNA, can be found at the ends the chromosomes, the telomeres, where they contribute to the preservation of these structures and thus prevent such as a rapid aging of our cells. Other family members are true functions in gene silencing (also known as the phenomenon of RNAi was awarded the 2006 Nobel Prize). RecQ helicases biochemically fulfill these functions in general, by recognizing specific DNA structures [1], and they dissolve in energy consumption again. If these functions in animal cells that then can develop cancer.
The vast majority of single-celled organisms have exactly one RecQ helicase, which fulfilled all-rounder, most of these tasks. Interestingly, but also complicate it in multicellular organisms, because they carry several genes for RecQ helicases in their genomes, which have divided the tasks among themselves. People such as 5, even 7 Arabidopsis RecQ genes. A fairly well-studied family member in humans is called BLM, because the mutation can trigger devastating hereditary disease Bloom syndrome . Functionally equivalent to the gene in Arabidopsis RECQ4A. Both suppress the recombination and are involved in certain types of DNA repair. At least one of these tasks are performed in the RTR complex, at issue today. Therefore I will let it also be good for now.
The second protein in the complex is a topoisomerase. It is TOP3 in the yeast, in multicellular TOPO3α called eukaryotes. Topoisomerases solve topological problems of DNA - that's why the name. A simple example will help to understand what was meant by this: Imagine a rubber band before, puts an end to its fixed to a door handle, the other you hold in your hand. Now twist (turns on) its the rubber band. How can resolve this over-rotation again, if the ends are firmly established? The DNA that is slightly easier than with a rubber band, but that is exactly what topoisomerases: cut a line through at this position, the rubber band / DNA now rotate freely. If the over-rotation was dissolved (this is done by the stored energy in the overturning of itself) includes the topoisomerase again the gap. A cut and glued rubber band would probably not use more, but this means only in the DNA, releasing and linking a bond in the molecule, which then makes no difference [2].
The third partner is complex in the yeast and human RMI1 BLAP75. Unlike the first two proteins, it seems to have no enzymatic function. Nevertheless, the complex is doing its job well if you remove this protein from it. This is probably because RMI1/BLAP75 time promotes the recognition of and binding to specific DNA structures, and other helicase and topoisomerase in the complex together. On This allows the two proteins fulfill their tasks cooperatively.
was shown recently that the complex also contains a protein called RMI2/BLAP18. This is closely related to RMI1, and both are complementary in their function. Moreover, it is already known that other, previously unidentified proteins are contained in the complex.
Because of the three core proteins of the complex but received its name - BTB for BLM, and TOPO3α BLAP75 in man or RTR for RecQ helicase, in the yeast TOP3 and RMI1. Exactly what he does with the DNA, I will go out in a separate post. Shortly I will mention only that the RTR complex recently, the sad Honor has been misused by creationists as "argument" to be .
[1] Anyone who has ever wondered where the nearest post of the series remains in DNA structures - guilty as charged. It's not like that because I ran out of topics. It goes further to soon, I promise!
[2] There is a second form of topoisomerases. The cut not one but two strands of DNA by. This is about necessary if more chromosomes are knotted together.
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