Interdependence, reflexivity, fidelity, impedance matching, and the evolution of genetic coding

Show simple item record Carter, C en Wills, Peter en 2019-02-28T02:19:49Z en 2017-05-17 en
dc.identifier.uri en
dc.description.abstract ABSTRACT Genetic coding is generally thought to have required ribozymes whose functions were taken over by polypeptide aminoacyl-tRNA synthetases (aaRS). Two discoveries about aaRS and their tRNA substrates now furnish a unifying rationale for the opposite conclusion: that the key processes of the Central Dogma of molecular biology emerged simultaneously and naturally from simple origins in a peptide•RNA partnership, eliminating the epistemological need for a prior RNA world. First, the two aaRS classes likely arose from opposite strands of the same ancestral gene, implying a simple genetic alphabet. Inversion symmetries in aaRS structural biology arising from genetic complementarity would have stabilized the initial and subsequent differentiation of coding specificities and hence rapidly promoted diversity in the proteome. Second, amino acid physical chemistry maps onto tRNA identity elements, establishing reflexivity in protein aaRS. Bootstrapping of increasingly detailed coding is thus intrinsic to polypeptide aaRS, but impossible in an RNA world. These notions underline the following concepts that contradict gradual replacement of ribozymal aaRS by polypeptide aaRS: (i) any set of aaRS must be interdependent; (ii) reflexivity intrinsic to polypeptide aaRS production dynamics promotes bootstrapping; (iii) takeover of RNA-catalyzed aminoacylation by enzymes will necessarily degrade specificity; (iv) the Central Dogma’s emergence is most probable when replication and translation error rates remain comparable. These characteristics are necessary and sufficient for the essentially de novo emergence of a coupled gene-replicase-translatase system of genetic coding that would have continuously preserved the functional meaning of genetically encoded protein genes whose phylogenetic relationships match those observed today. en
dc.relation.ispartof bioRxiv en
dc.rights Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. Previously published items are made available in accordance with the copyright policy of the publisher. en
dc.rights.uri en
dc.title Interdependence, reflexivity, fidelity, impedance matching, and the evolution of genetic coding en
dc.type Report en
dc.identifier.doi 10.1101/139139 en
dc.rights.holder Copyright: The author en
pubs.publication-status Published en
dc.rights.accessrights en
pubs.subtype Working Paper en
pubs.elements-id 750810 en
dc.relation.isnodouble 1026870 * Science en Physics en
pubs.number 139139v1 en
pubs.record-created-at-source-date 2019-07-29 en

Files in this item

There are no files associated with this item.

Find Full text

This item appears in the following Collection(s)

Show simple item record


Search ResearchSpace