DNA and RNA - Deoxyribonucleic acid and ribonucleic acid are the most important parts of the human body. DNA —
At school we learn that DNA is double-strandedstructure, and RNA is single-stranded. But this is not entirely true. Scientists were faced with a situation where RNA formed a double-stranded (so-called secondary) structure, which plays an important role in the functioning of its molecules. These structures are involved in the regulation of gene expression, where the double-stranded regions usually have specific functions and, if lost, can cause serious disorders. The double-stranded structure is created by sticky additional regions.
The RNA contains the following nucleosides:
- Adenine + ribose = adenosine (A)
- Guanine + ribose = guanosine (G)
- Cytosine + ribose = cytidine (C)
- Uracil + ribose = uridine (U)
In the case of nucleic acids, both oligo andpolynucleotides - nitrogenous bases of nucleotides are capable, due to the formation of hydrogen bonds, to form paired complexes of adenine-thymine (or uracil in RNA) and guanine-cytosine during the interaction of nucleic acid chains. This interaction is called complementarity of nucleic acids, and it plays a key role in a number of fundamental processes of storage and transmission of genetic information: DNA replication, which ensures the transfer of genetic information during cell division, transcription of DNA into RNA during the synthesis of proteins encoded by the DNA of a gene, storage of genetic information in double-stranded DNA and DNA repair processes when damaged.
In other words, so that parts of the RNA “stick” to each otherBy the way, the letters U and G should appear opposite A and C, respectively. Most of the sticking areas are located close to each other. However, the role of those located at a distance is not entirely clear.
Scientists from the Skoltech Center for Life Sciences underled by Professor Dmitry Pervushin and their colleagues from Russian and international laboratories, conducted a joint study. They used molecular and bioinformatics techniques to analyze the structure and role of complementary RNA regions that are far apart but capable of forming secondary structures.
In general, RNA has two structures - primary and secondary.
Under the primary structure of nucleic acidsunderstand the order and sequence of arrangement of mononucleotides in the polynucleotide chain of RNA. Such a chain is stabilized by 3′,5′-phosphodiester bonds. In turn, secondary structure is the conformational arrangement of the main chain of a macromolecule (for example, a polypeptide chain of a protein or a chain of nucleic acids), regardless of the conformation of the side chains or the relationship to other segments. In describing the secondary structure, it is important to determine the hydrogen bonds that stabilize individual fragments of macromolecules.
Thanks to the new work, it turned out that the secondarystructure plays an important role in the maturation of information-carrying RNA molecules, and especially in splicing. This is a process in which the non-coding regions are excised and the coding regions are stitched together (as in the maturation of RNA molecules). Scientists have shown that RNA secondary structures can regulate splicing and thus contribute more to gene regulation than previously thought.
Biologists have published an extensive catalogpotentially important RNA structures based on calculations. However, the authors of the work note that experimental research in this direction is just beginning.
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RNA is made up of a long chain in which each link is called a nucleotide.
In the vast majority of living organisms, DNA consists not of one, but of two polynucleotide chains. These two long chains are twisted around each other in a double helix.
Gene expression is the process by which hereditary information from a gene is converted into a functional product - RNA or protein.
Molecule conformation - the spatial arrangement of atoms in a molecule of a certain configuration.