The researchers assessed the ability of the molecules to the selfligation.
Scientists from the U.S. and South Africa proved that a short nucleotide chains of RNA can spontaneously connect with each other and form large molecules. This ability is necessary for the occurrence in its primeval soup of compounds with enzymatic activity that stores genetic information. Article researchers published in the journal Royal Society Open Science.
According to the hypothesis of RNA world, the predecessors of living cells were molecules-enzymes (ribozymes) that can copy themselves (replicate). It is known that such compounds are large and complex. They were formed from smaller molecules through a process called banding, when two nucleotide chains bind ends. However, this reaction is performed by a separate group of enzymes (ligase), so the RNA-world would be impossible without the presence of ribosomal providing its own ligation.
The object of the study, the researchers used a complex ribozyme RNA polymerase R18. This large molecule has two active centre. One of them carries a polymerase activity, i.e., synthesize a molecule of RNA from nucleotides, the other is Lightnin core. Specialists were removed from various fragments of hammerhead ribozyme, having a number of small chains, all of which had rigirously center. Latest and full R18 polymerase, was placed in environment which contained other small RNA molecules (substrates).
The researchers assessed the ability of the molecules to the selfligation. R18 showed very low activity, however, the smallest chain (R18-T4) were attached to a variety of RNA molecules. With increasing chain length legana activity fell, and the molecule was able to bind only with certain substrates. According to experts, ribozymes acquire specificity, characteristic of enzyme in living cells.
The results of the study showed that in the early stages of RNA world large molecules came about through the merger of Ligas with a variety of small RNA chains. Such compounds initially could not effectively carry out enzymatic functions, like copy itself, however, had the specificity to particular substrates. In the course of molecular evolution and their ability to replicate increased.
© 2017 – 2019, paradox. All rights reserved.
