Characterisation of the Essential t6A tRNA Modification Enzymes and Evaluation as a Potential Novel Antimicrobial Target
type: CreativeWork
description: Modified bases in RNA molecules are common, with over one-hundred individual modifications reported to date. In transfer RNA (tRNA), these modifications help hold the molecule in its proper conformation, allow the aminoacyl-synthetases to attach the amino acid to the correct tRNA for transfer to the ribosome, and in the correct matching of the codon-anticodon pair at the ribosome. Two positions on the tRNA molecule are significant in this last action; positions 34 and 37. Position 34 is the first base in the anticodon, and pairs with the last base in the codon during translation; modifications at this point allow the anticodon to pair with multiple codons. Modifications at position 37 help stabilise the anticodon loop of the tRNA, and help the efficiency of the translation. The threonylcarbamyoladenosine (t6A) modification at position 37 is required for the efficient translation of ANN codons. At least four enzymes, TsaBCDE, are involved in the formation of this modification, and are essential for bacterial viability. In this study, the interactions between the TsaB, TsaC, TsaD and TsaE have been investigated. Protein complex formation has been identified both in-vitro and in-vivo between TsaB and TsaD. The proteins interact in a 1:1 ratio, and the results indicate that this interaction stabilises the TsaD enzyme. The interaction appears to be unchanged over a physiological range of temperatures. No stable complex was identified between TsaC or TsaE with any of the other enzymes, however calorimetry suggests that there is an interaction between TsaE and both TsaB and TsaD. TsaC is believed to synthesise the threonylcarbamoyladenylate intermediate from threonine, bicarbonate and ATP; the activity of the enzyme complex (as measured by ATPase activity) in a media containing these compounds is increased in the presence of TsaC. If the cell is prevented from maintaining a source of t6A, it mounts a number of transcriptional responses. The transcription of certain amino a…
abstract: Modified bases in RNA molecules are common, with over one-hundred individual modifications reported to date. In transfer RNA (tRNA), these modifications help hold the molecule in its proper conformation, allow the aminoacyl-synthetases to attach the amino acid to the correct tRNA for transfer to the ribosome, and in the correct matching of the codon-anticodon pair at the ribosome. Two positions on the tRNA molecule are significant in this last action; positions 34 and 37. Position 34 is the first base in the anticodon, and pairs with the last base in the codon during translation; modifications at this point allow the anticodon to pair with multiple codons. Modifications at position 37 help stabilise the anticodon loop of the tRNA, and help the efficiency of the translation. The threonylcarbamyoladenosine (t6A) modification at position 37 is required for the efficient translation of ANN codons. At least four enzymes, TsaBCDE, are involved in the formation of this modification, and are essential for bacterial viability. In this study, the interactions between the TsaB, TsaC, TsaD and TsaE have been investigated. Protein complex formation has been identified both in-vitro and in-vivo between TsaB and TsaD. The proteins interact in a 1:1 ratio, and the results indicate that this interaction stabilises the TsaD enzyme. The interaction appears to be unchanged over a physiological range of temperatures. No stable complex was identified between TsaC or TsaE with any of the other enzymes, however calorimetry suggests that there is an interaction between TsaE and both TsaB and TsaD. TsaC is believed to synthesise the threonylcarbamoyladenylate intermediate from threonine, bicarbonate and ATP; the activity of the enzyme complex (as measured by ATPase activity) in a media containing these compounds is increased in the presence of TsaC. If the cell is prevented from maintaining a source of t6A, it mounts a number of transcriptional responses. The transcription of certain amino a…
author: Cargill, James Stuart
language: eng
date published: 2014
date modified: 2026-07-24T02:07:59Z
provider: University of Dundee
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Dundee