Origin of the 16S Ribosomal Molecule from Ancestor tRNAs

• Published in: Journal of molecular evolution Vol. 89; no. 4-5; pp. 249 - 256
• Main Authors: de Farias, Savio Torres, Rêgo, Thais Gaudêncio, José, Marco V.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-06-2021; Springer Nature B.V
• Subjects: Animal Genetics and Genomics; Biomedical and Life Sciences; Cell Biology; Concatamers; Evolutionary Biology; Genetic code; Hypotheses; Life Sciences; Microbiology; Nucleotide sequence; Original Article; Plant Genetics and Genomics; Plant Sciences; Ribosomal subunits; rRNA 16S; tRNA; 16S rRNA; Origins; Evolution; Proto-tRNAs; Translation system
• ISSN: 0022-2844; 1432-1432
• DOI: 10.1007/s00239-021-10002-8

We tested the hypothesis that concatemers of ancestral tRNAs gave rise to the 16S ribosomal RNA. We built an ancestral sequence of proto-tRNAs that showed a significant identity of 51.69% and a percentage of structural identity of 0.941 with the 3′ upper domain of 16S ribosomal molecule. We also propose a hypothesis in which the small ribosomal subunit emerged by proto-tRNA fusion and worked as a point to bind RNAs in an open structure configuration. In this context, the two ribosomal subunits initially worked independently, and that the subunit junction, with consequent primitive ribosome formation, was mediated by interactions with tRNA molecules during the primordial genetic code formation.