The "grammar of life" born before DNA – Biotech

The grammar of life, which establishes how to bind the & # 39; letters "at the base of the genetic code, was born spontaneously even before the DNA: contrary to what has been thought up to now, in fact, the selective coupling of nitrogenous bases (discovered in 1953 Watson and Crick) is not an intrinsic property of the DNA filaments, but the same nitrogenous bases that form them. This is demonstrated by the study published in the journal of the American Academy of Sciences (PNA) by the University of Milan in collaboration with the University of Colorado.

The researchers used polarized microscopy and X-ray diffraction to observe the behavior of simple nitrogenous bases (adenine, thymine, cytosine, guanine) dissolved in water: they thus discovered that they are self-badembled in base-pair columns, but only if the Watson-Crick selective rule is respected (adenosine with thymine and cytosine with guanine).

The discovery suggests that, if the stacking of nitrogenous base pairs forms spontaneously, this could be the cause and not the effect of the chemical bond that unites them in the filament. This is actually the hypothesis on which the two research groups, led by Tommaso Bellini, of the Biometra Department of the University of Milan, and Noel Clark of the University of Colorado, are have been concentrating for a decade.

The main mysteries about the origin of life are the formation of the first biopolymers, which seem to require a selectivity that can not be attributed to the formation of random chemical bonds. The spontaneous formation of columns of chemically independent base pairs, in which these small molecules are held together by physical forces, may have favored and guided the formation of chemical bonds that transformed these columns into true double helices of DNA or of Rna, the first to appear on our planet.