Aminoacyl-tRNA synthetases (aaRSs) play a crucial role in protein translation by linking tRNAs with cognate amino acids. Among all the tRNAs, only tRNA(His) bears a guanine base at position -1 (G-1), and it serves as a major recognition element for histidyl-tRNA synthetase (HisRS). Despite strong interests in the histidylation mechanism, the tRNA recognition and aminoacylation details are not fully understood. We herein present the 2.55 Å crystal structure of HisRS complexed with tRNA(His), which reveals that G-1 recognition is principally nonspecific interactions on this base and is made possible by an enlarged binding pocket consisting of conserved glycines. The anticodon triplet makes additional specific contacts with the enzyme but the rest of the loop is flexible. Based on the crystallographic and biochemical studies, we inferred that the uniqueness of histidylation system originates from the enlarged binding pocket (for the extra base G-1) on HisRS absent in other aaRSs, and this structural complementarity between the 5' extremity of tRNA and enzyme is probably a result of coevolution of both.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4357726 | PMC |
http://dx.doi.org/10.1093/nar/gkv129 | DOI Listing |
Arthritis Rheumatol
December 2024
Institute for Clinical and Translational Research, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA.
Objective: Idiopathic inflammatory myopathies (myositis, IIMs) are rare, systemic autoimmune disorders that lead to muscle inflammation, weakness, and extra-muscular manifestations, with a strong genetic component influencing disease development and progression. Previous genome-wide association studies identified loci associated with IIMs. In this study, we imputed data from two prior genome-wide myositis studies and analyzed the largest myositis dataset to date to identify novel risk loci and susceptibility genes associated with IIMs and its clinical subtypes.
View Article and Find Full Text PDFPNAS Nexus
December 2024
Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
GCN2 is a conserved receptor kinase activating the integrated stress response (ISR) in eukaryotic cells. The ISR kinases detect accumulation of stress molecules and reprogram translation from basal tasks to preferred production of cytoprotective proteins. GCN2 stands out evolutionarily among all protein kinases due to the presence of a histidyl-tRNA synthetase-like (HRSL) domain, which arises only in GCN2 and is located next to the kinase domain (KD).
View Article and Find Full Text PDFMicrob Pathog
January 2025
Department of Biotechnology, Panjab University, Sector-25, South Campus, Chandigarh, 160025, India.
Nucleic Acids Res
December 2024
Department of Biochemistry, The University of Western Ontario, London, Ontario N6A 5C1, Canada.
Aminoacyl-tRNA synthetases are indispensable enzymes in all cells, ensuring the correct pairing of amino acids to their cognate tRNAs to maintain translation fidelity. Autosomal dominant mutations V133F and Y330C in histidyl-tRNA synthetase (HARS) cause the genetic disorder Charcot-Marie-Tooth type 2W (CMT2W). Treatments are currently restricted to symptom relief, with no therapeutic available that targets the cause of disease.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
Department of Biotechnology & Bioinformatics, School of Life Sciences, University of Hyderabad, Prof. C.R. Rao Road, Hyderabad 500046, India. Electronic address:
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!