Abstract
The origin of biomolecular machinery likely centered around an ancient and central molecule capable of interacting with emergent macromolecular complexity. tRNA is the oldest and most central nucleic acid molecule of the cell. Its co-evolutionary interactions with aminoacyl-tRNA synthetase protein enzymes define the specificities of the genetic code and those with the ribosome their accurate biosynthetic interpretation. Phylogenetic approaches that focus on molecular structure allow reconstruction of evolutionary timelines that describe the history of RNA and protein structural domains. Here we review phylogenomic analyses that reconstruct the early history of the synthetase enzymes and the ribosome, their interactions with RNA, and the inception of amino acid charging and codon specificities in tRNA that are responsible for the genetic code. We also trace the age of domains and tRNA onto ancient tRNA homologies that were recently identified in rRNA. Our findings reveal a timeline of recruitment of tRNA building blocks for the formation of a functional ribosome, which holds both the biocatalytic functions of protein biosynthesis and the ability to store genetic memory in primordial RNA genomic templates.
Highlights
Uncovering patterns and processes responsible for the origin of life in extant macromolecules is a most challenging proposition
No clear link has been found that explains how the 123,870 models of molecular structure deposited in the entries of the PROTEIN DATA BANK (PDB) [6] and their associated functions are encoded in the DNA of the 10,045 genomes and metagenomes that have been completely sequenced (GOLD DATABASE [7]) and that have given rise to 0.55 million UNIPROTKB / SWISSPROT
A number of fold family (FF) appeared ~3.7–3.6 Gy-ago after the rise of metabolism (Figure 2). These structures catalyzed crucial acylation and condensation reactions involved in aminoacylation of transfer RNA (tRNA) bound to aminoacyl-tRNA synthetases or phosphopantetheinyl arms of carrier proteins that are part of non-ribosomal peptide synthetase (NRPS) complexes
Summary
Uncovering patterns and processes responsible for the origin of life in extant macromolecules is a most challenging proposition. Phylogenetic trees or networks are built from useful biological features of evolving taxa, which are known as phylogenetic “characters” These characters are usually building blocks (parts) of more complex physical or functional systems (wholes). The evolutionary unification of building blocks results in new emerging systems (defined below), which diversify We exemplify this process with a mathematical abstraction (Figure 1d) in which the edges of a primordial root network join to form an ancestor trunk edge. When considering all biological parts, the tree-like structure describes the evolution of biological systems; (d) The abstraction of panel c can be defined by two networks (root and crown networks) joined by a common edge (trunk). These methods are capable of distinguishing similarity due to common ancestry from similarities due to other causes that are not evolutionary
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
