Among the large and diverse collection of tRNA modifications, 7-methylguanosine (mG) is frequently found in the tRNA variable loop at position 46. This modification is introduced by the TrmB enzyme, which is conserved in bacteria and eukaryotes. However, the molecular determinants and the mechanism for tRNA recognition by TrmB are not well understood. Complementing the report of various phenotypes for different organisms lacking TrmB homologs, we report here hydrogen peroxide sensitivity for the Escherichia coli ΔtrmB knockout strain. To gain insight into the molecular mechanism of tRNA binding by E. coli TrmB in real time, we developed a new assay based on introducing a 4-thiouridine modification at position 8 of in vitro transcribed tRNA enabling us to fluorescently label this unmodified tRNA. Using rapid kinetic stopped-flow measurements with this fluorescent tRNA, we examined the interaction of WT and single substitution variants of TrmB with tRNA. Our results reveal the role of S-adenosylmethionine for rapid and stable tRNA binding, the rate-limiting nature of mG46 catalysis for tRNA release, and the importance of residues R26, T127, and R155 across the entire surface of TrmB for tRNA binding.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC10130221 | PMC |
http://dx.doi.org/10.1016/j.jbc.2023.104612 | DOI Listing |
J Genet Genomics
January 2025
National Engineering Laboratory of Crop Stress Resistance, College of Life Science, Anhui Agricultural University, Hefei, Anhui 230036, China. Electronic address:
Mitochondria are semi-autonomous organelle present in eukaryotic cells, containing their own genome and transcriptional machinery. However, their functions are intricately linked to proteins encoded by the nuclear genome. Mitochondrial transcription termination factors (mTERFs) are nucleic acid-binding proteins involved in RNA splicing and transcription termination within plant mitochondria and chloroplasts.
View Article and Find Full Text PDFInt J Mol Sci
January 2025
Pathogenesis and Control of Pathogenic Microorganisms Research Team, School of Life and Health Sciences, Hainan Province Key Laboratory of One Health, Collaborative Innovation Center of One Health, Hainan University, Haikou 570228, China.
The trans-translation system, mediated by transfer-messenger RNA (tmRNA, encoded by the gene) and its partner protein SmpB, helps to release ribosomes stalled on defective mRNA and targets incomplete protein products for hydrolysis. Knocking out the and genes in various pathogens leads to different phenotypic changes, indicating that they have both cooperative and independent functionalities. This study aimed to clarify the functional relationships between tmRNA and SmpB in a pathogen that poses threats in aquaculture and human health.
View Article and Find Full Text PDFInt J Mol Sci
January 2025
Vavilov Institute of General Genetics Russian Academy of Sciences, 119333 Moscow, Russia.
The size of viral genomes is limited, thus the majority of encoded proteins possess multiple functions. The main function of tobamoviral movement protein (MP) is to perform plasmodesmata gating and mediate intercellular transport of the viral RNA. MP is a remarkable example of a protein that, in addition to the initially discovered and most obvious function, carries out numerous activities that are important both for the manifestation of its key function and for successful and productive infection in general.
View Article and Find Full Text PDFEcotoxicol Environ Saf
January 2025
College of Resources and Environment, Henan Institute of Science and Technology, Xinxiang, Henan Province 453003, China. Electronic address:
Fomesafen is a herbicide with long persistence in soil, causing damage to succeeding crops. Dichlormid is a widely used safener protecting maize from chloroacetanilide and thiocarbamate injury. We found that dichlormid treatment could restore the growth of wheat seedlings exposed to fomesafen stress.
View Article and Find Full Text PDFPLoS One
January 2025
Department of Biotechnology and Bioengineering, Chonnam National University, Gwangju, Republic of Korea.
With the advancement of genetic code expansion, the field is progressing towards incorporating multiple non-canonical amino acids (ncAAs). The specificity of aminoacyl-tRNA synthetases (aaRSs) towards ncAAs is a critical factor, as engineered aaRSs frequently show polyspecificity, complicating the precise incorporation of multiple ncAAs. To address this challenge, predicting binding affinity can be beneficial.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!