The involvement of tRNA structural elements beyond the anticodon in aminoacyl-tRNA (aa-tRNA) selection by the ribosome has revealed that substrate recognition is considerably more complex than originally envisioned in the adaptor hypothesis. By combining recent breakthroughs in aa-tRNA synthesis and mechanistic and structural studies of protein synthesis, we have investigated whether aa-tRNA recognition further extends to the amino acid, which would explain various translation disorders exhibited by misacylated tRNAs. Contrary to expectation, we find that natural amino acids misacylated onto natural but non-native tRNAs are selected with efficiencies very similar to those of their correctly acylated counterparts. Despite this, small but reproducible differences in selection indeed demonstrate that the translational machinery is sensitive to the amino acid-tRNA pairing. These results suggest either that the ribosome is an exquisite sensor of natural versus unnatural amino acid-tRNA pairings and/or that aa-tRNA selection is not the primary step governing the amino acid specificity of the ribosome.
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http://dx.doi.org/10.1038/nchembio.255 | DOI Listing |
Adv Sci (Weinh)
March 2025
National Key Facility for Crop Gene Resources and Genetic Improvement/Key laboratory Grain Crop Genetic Resources Evaluation and Utilization Ministry of Agriculture and Rural Affairs, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, P. R. China.
Tartary buckwheat (Fagopyrum tataricum) is esteemed as a medicinal crop due to its high nutritional and health value. However, the genetic basis for the variations in Tartary buckwheat grain ionome remains inadequately understood. Through genome-wide association studies (GWAS) on grain ionome, 52 genetic loci are identified associated with 10 elements undergoing selection.
View Article and Find Full Text PDFBeilstein J Org Chem
March 2025
Laboratory of Organic Chemistry, ETH Zürich, Vladimir-Prelog-Weg 3, 8093 Zürich, Switzerland.
Tryptophan fulfills a plethora of important functions in nature both in its free form and as a component of peptides and proteins. Selective binding of tryptophan is therefore important for diagnostic and medicinal applications. Recently, we reported a glucose naphtho crown ether which is a chemoselective receptor for the esters of aromatic amino acids, in particular tryptophan, in water.
View Article and Find Full Text PDFBeilstein J Org Chem
March 2025
Department of Chemistry, Organic and Bioorganic Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany.
Drug conjugates using toxic payloads are a promising approach for selectively combating cancer while sparing healthy tissue. The lack of highly cytotoxic and at the same time selective therapeutics against cancer is an ongoing challenge. Cryptophycins are a class of cyclic depsipeptides renowned for their high cytotoxicity in the picomolar range often combined with efficacy against multidrug-resistant tumour cell lines.
View Article and Find Full Text PDFImmune Netw
February 2025
Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, Korea.
Aromatic amino acid (AAA) metabolites, derived from tryptophan, phenylalanine, and tyrosine through coordinated host and microbial metabolism, have emerged as critical modulators of immune function. We examine the complex journey of AAAs from dietary intake through intestinal absorption and metabolic transformation, highlighting the crucial role of host-microbe metabolic networks in generating diverse immunomodulatory compounds. This review provides a unique integrative perspective by mapping the molecular mechanisms through which these metabolites orchestrate immune responses.
View Article and Find Full Text PDFMol Pharm
March 2025
Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
Peptides are highly receptor-affine molecules exhibiting suitable pharmacokinetics. Additionally, low-cost production, simple protocols allowing easy modifications, and tolerance toward harsh reaction conditions make peptides ideal ligands for preparation of radiopharmaceuticals for cancer detection and treatment. However, natural peptides being substrates for enzymes are susceptible to proteolysis, which limits the lifetime and the target uptake.
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