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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...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Taylor & Francis
2018
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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 |
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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 |
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