The regulation of the expression of thrS, the structural gene for threonyl-tRNA synthetase, was studied using several thrS-lac fusions cloned in lambda and integrated as single copies at att lambda. It is first shown that the level of beta-galactosidase synthesized from a thrS-lac protein fusion is increased when the chromosomal copy of thrS is mutated. It is also shown that the level of beta-galactosidase synthesized from the same protein fusion is decreased if wild-type threonyl-tRNA synthetase is overproduced from a thrS-carrying plasmid. These results strongly indicate that threonyl-tRNA synthetase controls the expression of its own gene. Consistent with this hypothesis it is shown that some thrS mutants overproduce a modified form of threonyl-tRNA synthetase. When the thrS-lac protein fusion is replaced by several types of thrS-lac operon fusions no effect of the chromosomal thrS allele on beta-galactosidase synthesis is observed. It is also shown that beta-galactosidase synthesis from a promoter-proximal thrS-lac operon fusion is not repressed by threonyl-tRNA synthetase overproduction. The fact that regulation is seen with a thrS-lac protein fusion and not with operon fusions indicates that thrS expression is autoregulated at the translational level. This is confirmed by hybridization experiments which show that under conditions where beta-galactosidase synthesis from a thrS-lac protein fusion is derepressed three- to fivefold, lac messenger RNA is only slightly increased.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/0022-2836(85)90185-8 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Nuclear Magnetic Resonance Fingerprinting and Principal Component Analysis Strategies Lead to Anti-Tuberculosis Natural Product Discovery from Actinomycetes.
Antibiotics (Basel)
January 2025
Institute for Biomedicine and Glycomics, Griffith University, Brisbane, QLD 4111, Australia.
Background: The increasing prevalence of drug-resistant tuberculosis (TB) underscores the urgent need for novel antimicrobial agents.
Methods: This study integrates cultivation optimization, nuclear magnetic resonance (NMR) fingerprinting, and principal component analysis (PCA) to explore microbial secondary metabolites as potential anti-TB agents.
Results: Using the combined approach, 11 bioactive compounds were isolated and identified, all exhibiting anti- BCG activity.
Potential Piperolactam A Isolated From Piper betle as Natural Inhibitors of Brucella Species Aminoacyl-tRNA Synthetase for Livestock Infections: In Silico Approach.
Vet Med Sci
November 2024
Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Sumedang, West Java, Indonesia.
Article Synopsis
- - Brucellosis, caused by the Brucella bacterium, leads to serious economic losses in livestock due to reproductive issues and reduced milk production, coupled with antibiotic resistance complicating treatment efforts.
- - This study focuses on isolating a compound called piperolactam A from Piper betle leaves, aiming to evaluate its potential as an antibacterial agent against Brucella sp. and its mechanism of action against specific enzymes in bacteria.
- - Through molecular docking methods, the research shows that piperolactam A exhibits strong binding affinity to leucyl-tRNA synthetase (LeuRS), suggesting it could effectively inhibit bacterial growth by disrupting protein synthesis.
Streptomyces-Fungus Co-Culture Enhances the Production of Borrelidin and Analogs: A Genomic and Metabolomic Approach.
Mar Drugs
June 2024
College of Ocean and Earth Science, Xiamen University, Xiamen 361005, China.
The marine Streptomyces harbor numerous biosynthetic gene clusters (BGCs) with exploitable potential. However, many secondary metabolites cannot be produced under laboratory conditions. Co-culture strategies of marine microorganisms have yielded novel natural products with diverse biological activities.
View Article and Find Full Text PDFSpecific glycine-dependent enzyme motion determines the potency of conformation selective inhibitors of threonyl-tRNA synthetase.
Commun Biol
July 2024
State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, 200032, Shanghai, China.
The function of proteins depends on their correct structure and proper dynamics. Understanding the dynamics of target proteins facilitates drug design and development. However, dynamic information is often hidden in the spatial structure of proteins.
View Article and Find Full Text PDFA model organism pipeline provides insight into the clinical heterogeneity of TARS1 loss-of-function variants.
HGG Adv
July 2024
Department of Human Genetics, University of Michigan, Ann Arbor, MI, USA; Department of Neurology, University of Michigan, Ann Arbor, MI, USA. Electronic address:
Aminoacyl-tRNA synthetases (ARSs) are ubiquitously expressed, essential enzymes that complete the first step of protein translation: ligation of amino acids to cognate tRNAs. Genes encoding ARSs have been implicated in myriad dominant and recessive phenotypes, the latter often affecting multiple tissues but with frequent involvement of the central and peripheral nervous systems, liver, and lungs. Threonyl-tRNA synthetase (TARS1) encodes the enzyme that ligates threonine to tRNA in the cytoplasm.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!