Behavior of a hammerhead ribozyme in aqueous solution at medium to high temperatures

Author(s): El-Murr N, Maurel MC, Rihova M, Vergne J, Hervé G, et al.

Abstract

The "RNA world" hypothesis proposes that--early in the evolution of life--RNA molecules played important roles both in information storage and in enzymatic functions. However, this hypothesis seems to be inconsistent with the concept that life may have emerged under hydrothermal conditions since RNA molecules are considered to be labile under such extreme conditions. Presently, the possibility that the last common ancestor of the present organisms was a hyperthermophilic organism which is important to support the hypothesis of the hydrothermal origin of life has been subject of strong discussions. Consequently, it is of importance to study the behavior of RNA molecules under hydrothermal conditions from the viewpoints of stability, catalytic functions, and storage of genetic information of RNA molecules and determination of the upper limit of temperature where life could have emerged. In the present work, self-cleavage of a natural hammerhead ribozyme was examined at temperatures 10-200 °C. Self-cleavage was investigated in the presence of Mg(2+), which facilitates and accelerates this reaction. Self-cleavage of the hammerhead ribozyme was clearly observed at temperatures up to 60 °C, but at higher temperatures self-cleavage occurs together with hydrolysis and with increasing temperature hydrolysis becomes dominant. The influence of the amount of Mg(2+) on the reaction rate was also investigated. In addition, we discovered that the reaction proceeds in the presence of high concentrations of monovalent cations (Na(+) or K(+)), although very slowly. Furthermore, at high temperatures (above 60 °C), monovalent cations protect the ribozyme against degradation.

Similar Articles

Potato spindle tuber "virus"

Author(s): Diener TO

Inhibition of potato spindle tuber viroid (PSTVd) infection with DNA oligonucleotides

Author(s): Matousek J, Trnena L, Arnold L, Dedic P, Rakousky S, et al.

The revised classification of eukaryotes

Author(s): Adl SM, Simpson AG, Lane CE, Lukes J, Bass D, et al.

Improving the coverage of the cyanobacterial phylum using diversity-driven genome sequencing

Author(s): Shih PM, Wu D, Latifi A, Axen SD, Fewer DP, et al.

Accurate strand-specific quantification of viral RNA

Author(s): Plaskon NE, Adelman ZN, Myles KM

Self-cleavage of plus and minus RNA transcripts of avocado sunblotch viroid

Author(s): Hutchins CJ, Rathjen PD, Forster AC, Symons RH