Class I and II aminoacyl-tRNA synthetase tRNA groove discrimination created the first synthetase-tRNA cognate pairs and was therefore essential to the origin of genetic coding.

ABSTRACT: The genetic code likely arose when a bidirectional gene replicating as a quasi-species began to produce ancestral aminoacyl-tRNA synthetases (aaRS) capable of distinguishing between two distinct sets of amino acids. The synthetase class division therefore necessarily implies a mechanism by which the two ancestral synthetases could also discriminate between two different kinds of tRNA substrates. We used regression methods to uncover the possible patterns of base sequences capable of such discrimination and find that they appear to be related to thermodynamic differences in the relative stabilities of a hairpin necessary for recognition of tRNA substrates by Class I aaRS. The thermodynamic differences appear to be exploited by secondary structural differences between models for the ancestra

SUBMITTER: Carter CW 

PROVIDER: S-EPMC6642019 | biostudies-literature | 2019 Aug

REPOSITORIES: biostudies-literature