Foreword

Abstract

The function of the glutaminyl-tRNA synthetase and Glu-tRNAGln amidotransferase might be related to the origin of the genetic code because, for example, glutaminyl-tRNA synthetase catalyses the fundamental reaction that makes the genetic code. If the evolutionary stage of the origin of these two enzymes could be unambiguously identified, then the genetic code should still have been originating at that particular evolutionary stage because the fundamental reaction that makes the code itself was still evidently evolving. This would result in that particular evolutionary moment being attributed to the evolutionary stage of the progenote because it would have a relationship between the genotype and the phenotype not yet fully realized because the genetic code was precisely still originating. I then analyzed the distribution of the glutaminyl-tRNA synthetase and Glu-tRNAGln aminodotrasferase in the main phyletic lineages. Since in some cases the origin of these two enzymes can be related to the evolutionary stages of ancestors of archaea and eukaryotes, this would indicate these ancestors as progenotes because at that evolutionary moment the genetic code was evidently still evolving, thus realizing the definition of progenote. The conclusion that the ancestor of archaea and that of eukaryotes were progenotes would imply that even the last universal common ancestor (LUCA) was a progenote because it appeared, on the tree of life, temporally before these ancestors.