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Updated: Jun 20, 2026
09:12
DNAzyme-dependent Analysis of rRNA 2’-O-Methylation
Published on: September 16, 2019
The coding properties of methyl-deficient leucyl-transfer RNA
1Laboratory of Biochemistry, National Institute of Dental Research, National Institutes of Health, Bethesda, Maryland 20014, USA.
Journal of Molecular Biology
|September 23, 2009
Summary
Methionine deprivation in Escherichia coli causes methyl-deficient transfer RNA (tRNA) synthesis. This altered tRNA exhibits distinct responses to messenger RNA codons, suggesting methylated bases are crucial for specific codon recognition.
Area of Science:
- Molecular Biology
- Microbiology
- Biochemistry
Background:
- Escherichia coli 58-161, a methionine auxotroph, exhibits relaxed control over protein synthesis.
- Methionine deprivation induces the synthesis of methyl-deficient transfer RNA (tRNA).
- Normal tRNA from E. coli fractionates into two peaks (I and II) on methylated albumin-kieselguhr columns.
Purpose of the Study:
- To investigate the functional consequences of methyl-deficient tRNA synthesis in E. coli.
- To determine if methyl-deficient tRNA affects codon recognition.
- To explore the role of methylated bases in tRNA for specific codon recognition.
Main Methods:
- Utilized [14C]leucyl-tRNA labeling and fractionation on methylated albumin-kieselguhr columns.
- Employed ribosome-binding assays to assess tRNA response to synthetic messenger RNAs (poly UC and poly UG).
- Compared normal and methyl-deficient [14C]leucyl-tRNA binding characteristics.
Main Results:
- Methyl-deficient [14C]leucyl-tRNA showed an additional component (peak III) upon chromatography.
- Compared to normal tRNA, methyl-deficient tRNA exhibited a twofold increase in poly UG response and a fivefold increase in poly UC response.
- The poly UG reactive tRNA was localized to peak II, while peak III responded exclusively to poly UC.
Conclusions:
- Methylation status of tRNA significantly impacts its codon recognition capabilities.
- Methyl-deficient tRNA displays altered responses to specific messenger RNA sequences (codons).
- These findings suggest a potential requirement for methylated bases in tRNA for precise codon recognition.
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