Related Experiment Video
Updated: Apr 27, 2026
Measurement of Specific Mycobacterial Mistranslation Rates with Gain-of-function Reporter Systems
Published on: April 26, 2019
Impairing methylations at ribosome RNA, a point mutation-dependent strategy for aminoglycoside resistance: the rsmG
Alfonso Benítez-Páez1, Sonia Cárdenas-Brito1, Mauricio Corredor2
1Grupo de Análisis Bioinformático, GABi, Centro de Investigación y Desarrollo en Biotecnología, CIDBIO, Bogotá, D.C, Colombia.
Introduction:
Aminoglycosides like streptomycin are well-known for binding at specific regions of ribosome RNA and then acting as translation inhibitors. Nowadays, several pathogens have been detected to acquire an undefined strategy involving mutation at non structural ribosome genes like those acting as RNA methylases. rsmG is one of those genes which encodes an AdoMet-dependent methyltransferase responsible for the synthesis of m 7 G527 in the 530 loop of bacterial 16S rRNA. This loop is universally conserved, plays a key role in ribosomal accuracy, and is a target for streptomycin binding. Loss of the m 7 G527 modification confers low-level streptomycin resistance and may affect ribosomal functioning.
Objectives:
After taking into account genetic information indicating that some clinical isolates of human pathogens show streptomycin resistance associated with mutations at rsmG , we decided to explore new hot spots for mutation capable of impairing the RsmG in vivo function and of promoting low-level streptomycin resistance.
Materials And Methods:
To gain insights into the molecular and genetic mechanism of acquiring this aminoglycoside resistance phenotype and the emergence of high-level streptomycin resistance in rsmG mutants, we mutated Escherichia coli rsmG and also performed a genotyping study on rpsL from several isolates showing the ability to grow at higher streptomycin concentrations than parental strains.
Results:
We found that the mutations at rpsL were preferentially present in these mutants, and we observed a clear synergy between rsmG and rpsL genes to induce streptomycin resistance.
Conclusion:
We contribute to understand a common mechanism that is probably transferable to other ribosome RNA methylase genes responsible for modifications at central sites for ribosome function.
Insights
Mutations in the rsmG gene can lead to streptomycin resistance in bacteria. Further mutations in rpsL synergize with rsmG mutations to significantly increase streptomycin resistance, revealing a common resistance mechanism.
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Background:
- Aminoglycosides, such as streptomycin, inhibit bacterial translation by binding to ribosomal RNA.
- Pathogens develop streptomycin resistance through mutations in non-structural ribosome genes, including RNA methylases like rsmG.
- The rsmG gene encodes a methyltransferase essential for m7G527 modification in the 16S rRNA 530 loop, a streptomycin binding site crucial for ribosomal accuracy.
Purpose of the Study:
- To investigate novel mutation hotspots that impair RsmG function and confer streptomycin resistance.
- To understand the molecular and genetic mechanisms underlying aminoglycoside resistance, particularly high-level streptomycin resistance in rsmG mutants.
Main Methods:
- Mutagenesis of the Escherichia coli rsmG gene.
- Genotyping analysis of the rpsL gene in bacterial isolates exhibiting increased streptomycin resistance compared to parental strains.
Main Results:
- Mutations in rpsL were frequently observed in streptomycin-resistant mutants.
- A synergistic effect between rsmG and rpsL mutations was identified, significantly enhancing streptomycin resistance.
Conclusions:
- This study elucidates a common mechanism of streptomycin resistance involving rsmG and rpsL.
- The findings suggest this mechanism is potentially transferable to other ribosome RNA methylase genes involved in essential ribosomal modifications.
Related Concept Videos
01:25Inhibitors of Bacterial Protein Synthesis
01:25Mechanism of Antibiotic Resistance in MRSA
01:23Types of RNA
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA...
01:56Riboswitches
The aptamer has high specificity for a particular metabolite which allows riboswitches to specifically regulate...
01:31Translation
Translation Produces the Building Blocks of Life
Proteins are...
01:31Translation
Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA), and other proteins produce a chain of amino acids—the polypeptide—as the end product of translation.
Translation Produces the Building Blocks of...