Cargando…

Aminoacyl-tRNA synthetase evolution and sectoring of the genetic code

The genetic code sectored via tRNA charging errors, and the code progressed toward closure and universality because of evolution of aminoacyl-tRNA synthetase (aaRS) fidelity and translational fidelity mechanisms. Class I and class II aaRS folds are identified as homologs. From sequence alignments, a...

Descripción completa

Detalles Bibliográficos
Autores principales: Pak, Daewoo, Kim, Yunsoo, Burton, Zachary F.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Taylor & Francis 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6104698/
https://www.ncbi.nlm.nih.gov/pubmed/29727262
http://dx.doi.org/10.1080/21541264.2018.1467718
_version_ 1783349537504493568
author Pak, Daewoo
Kim, Yunsoo
Burton, Zachary F.
author_facet Pak, Daewoo
Kim, Yunsoo
Burton, Zachary F.
author_sort Pak, Daewoo
collection PubMed
description The genetic code sectored via tRNA charging errors, and the code progressed toward closure and universality because of evolution of aminoacyl-tRNA synthetase (aaRS) fidelity and translational fidelity mechanisms. Class I and class II aaRS folds are identified as homologs. From sequence alignments, a structurally conserved Zn-binding domain common to class I and class II aaRS was identified. A model for the class I and class II aaRS alternate folding pathways is posited. Five mechanisms toward code closure are highlighted: 1) aaRS proofreading to remove mischarged amino acids from tRNA; 2) accurate aaRS active site specification of amino acid substrates; 3) aaRS-tRNA anticodon recognition; 4) conformational coupling proofreading of the anticodon-codon interaction; and 5) deamination of tRNA wobble adenine to inosine. In tRNA anticodons there is strong wobble sequence preference that results in a broader spectrum of contacts to synonymous mRNA codon wobble bases. Adenine is excluded from the anticodon wobble position of tRNA unless it is modified to inosine. Uracil is generally preferred to cytosine in the tRNA anticodon wobble position. Because of wobble ambiguity when tRNA reads mRNA, the maximal coding capacity of the three nucleotide code read by tRNA is 31 amino acids + stops.
format Online
Article
Text
id pubmed-6104698
institution National Center for Biotechnology Information
language English
publishDate 2018
publisher Taylor & Francis
record_format MEDLINE/PubMed
spelling pubmed-61046982018-08-27 Aminoacyl-tRNA synthetase evolution and sectoring of the genetic code Pak, Daewoo Kim, Yunsoo Burton, Zachary F. Transcription Research Paper The genetic code sectored via tRNA charging errors, and the code progressed toward closure and universality because of evolution of aminoacyl-tRNA synthetase (aaRS) fidelity and translational fidelity mechanisms. Class I and class II aaRS folds are identified as homologs. From sequence alignments, a structurally conserved Zn-binding domain common to class I and class II aaRS was identified. A model for the class I and class II aaRS alternate folding pathways is posited. Five mechanisms toward code closure are highlighted: 1) aaRS proofreading to remove mischarged amino acids from tRNA; 2) accurate aaRS active site specification of amino acid substrates; 3) aaRS-tRNA anticodon recognition; 4) conformational coupling proofreading of the anticodon-codon interaction; and 5) deamination of tRNA wobble adenine to inosine. In tRNA anticodons there is strong wobble sequence preference that results in a broader spectrum of contacts to synonymous mRNA codon wobble bases. Adenine is excluded from the anticodon wobble position of tRNA unless it is modified to inosine. Uracil is generally preferred to cytosine in the tRNA anticodon wobble position. Because of wobble ambiguity when tRNA reads mRNA, the maximal coding capacity of the three nucleotide code read by tRNA is 31 amino acids + stops. Taylor & Francis 2018-05-30 /pmc/articles/PMC6104698/ /pubmed/29727262 http://dx.doi.org/10.1080/21541264.2018.1467718 Text en © 2018 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. http://creativecommons.org/licenses/by-nc-nd/4.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License (http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited, and is not altered, transformed, or built upon in any way.
spellingShingle Research Paper
Pak, Daewoo
Kim, Yunsoo
Burton, Zachary F.
Aminoacyl-tRNA synthetase evolution and sectoring of the genetic code
title Aminoacyl-tRNA synthetase evolution and sectoring of the genetic code
title_full Aminoacyl-tRNA synthetase evolution and sectoring of the genetic code
title_fullStr Aminoacyl-tRNA synthetase evolution and sectoring of the genetic code
title_full_unstemmed Aminoacyl-tRNA synthetase evolution and sectoring of the genetic code
title_short Aminoacyl-tRNA synthetase evolution and sectoring of the genetic code
title_sort aminoacyl-trna synthetase evolution and sectoring of the genetic code
topic Research Paper
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6104698/
https://www.ncbi.nlm.nih.gov/pubmed/29727262
http://dx.doi.org/10.1080/21541264.2018.1467718
work_keys_str_mv AT pakdaewoo aminoacyltrnasynthetaseevolutionandsectoringofthegeneticcode
AT kimyunsoo aminoacyltrnasynthetaseevolutionandsectoringofthegeneticcode
AT burtonzacharyf aminoacyltrnasynthetaseevolutionandsectoringofthegeneticcode