Abstract:
As you know, the secondary structure of RNA molecules, unlike DNA, in addition to canonical or Watson-Crick pairs, non-canonical G-U pairs, this is guanine - uracil. The last pairs were established experimentally by X-ray diffraction analysis and are still a mystery to researchers. The fact is that such pairs are 5-10 times energetically weaker than the canonical pairs A-U, C-G. The question arises: why are such pairs needed?
The study was carried out in the framework of the strict mathematical analogy established earlier by the authors of some cases of genetic overlaps and stems of the secondary structure of messenger RNAs. In this work, it is shown that due to the non-canonical G-U pair, using the new ambiguities found, it is possible to substantially “regulate” the stem free energy (even for small stems) - the most important biochemical characteristic. It turned out that the discovered effect for G-U pairs significantly exceeds a similar effect for canonical pairs A-U, C-G.
Keywords:genetic code, non-canonical pairs G-U, free energy of the stem, new ambiguities.