A5086977810- RNA and protein synthesis mechanisms
- RNA modifications and cancer
- RNA Research and Splicing
- Porphyrin Metabolism and Disorders
- CRISPR and Genetic Engineering
- Genomics and Phylogenetic Studies
- RNA regulation and disease
- Bacterial Genetics and Biotechnology
- Heme Oxygenase-1 and Carbon Monoxide
- MicroRNA in disease regulation
- Photosynthetic Processes and Mechanisms
- PI3K/AKT/mTOR signaling in cancer
- RNA Interference and Gene Delivery
- Advanced biosensing and bioanalysis techniques
- Microbial Metabolic Engineering and Bioproduction
- Biochemical and Molecular Research
- Metabolism, Diabetes, and Cancer
- Hemoglobin structure and function
- Enzyme Structure and Function
- Polyamine Metabolism and Applications
- Bacteriophages and microbial interactions
- Genetics, Bioinformatics, and Biomedical Research
- Biosensors and Analytical Detection
- Hereditary Neurological Disorders
- Selenium in Biological Systems
Western University
2016-2025
Children’s Health Research Institute
2024-2025
Yale University
2009-2013
Institute of Macromolecular Chemistry
2012
Technische Universität Braunschweig
2006-2009
Whitney Museum of American Art
2009
Genetically encoded phosphoserine incorporation programmed by the UAG codon was achieved addition of engineered elongation factor and an archaeal aminoacyl-tRNA synthetase to normal Escherichia coli translation machinery (Park et al., 2011) Science 333, 1151). However, protein yield suffers from expression orthogonal system competition with release 1 (RF-1). In a strain lacking RF-1, phosphatase, where seven codons residing in essential genes were converted UAA, into GFP WNK4 significantly...
Over 300 amino acids are found in proteins nature, yet typically only 20 genetically encoded. Reassigning stop codons and use of quadruplet emerged as the main avenues for encoding non‐canonical (NCAAs). Canonical aminoacyl‐tRNAs with near‐cognate anticodons also read these to some extent. This background suppression leads ‘statistical protein’ that contains natural acid(s) at a site intended NCAA. We characterize amber, opal codon common Escherichia coli laboratory strains find PylRS/tRNA...
The worldwide COVID-19 pandemic caused by the SARS-CoV-2 betacoronavirus has highlighted need for a synthetic biology approach to create reliable and scalable sources of viral antigen uses in diagnostics, therapeutics basic biomedical research. Here, we adapt plasmid-based systems eukaryotic microalgae Phaeodactylum tricornutum develop an inducible overexpression system proteins. Limiting phosphate iron growth media induced expression receptor-binding domain (RBD) spike protein from P. HASP1...
Despite the fact that genetic code is known to vary between organisms in rare cases, it believed lifetime of a single cell stable. We found Acetohalobium arabaticum cells grown on pyruvate genetically encode 20 amino acids, but presence trimethylamine (TMA), A. dynamically expands its 21 acids including pyrrolysine (Pyl). only organism modulates size response environment and energy source. The gene cassette pylTSBCD , required biosynthesize UAG codons as Pyl, present genomes 24 anaerobic...
High-fidelity translation and a strictly accurate proteome were originally assumed as essential to life cellular viability. Yet recent studies in bacteria eukaryotic model organisms suggest that proteome-wide mistranslation can provide selective advantages is tolerated the cell at higher levels than previously thought (one error 6.9 × 10-4 yeast) with limited impact on phenotype. Previously, we selected tRNAPro containing single mutation induces alanine proline codons yeast. Yeast tolerate...
tRNA His guanylyltransferase (Thg1) post-transcriptionally adds a G (position −1) to the 5′-terminus of . The Methanosarcina acetivorans Thg1 (MaThg1) gene contains an in-frame TAG (amber) codon. Although UAG codon typically directs translation termination, its presence in mRNA may lead pyrrolysine (Pyl) incorporation achieved by Pyl-tRNA Pyl , product pyrrolysyl-tRNA synthetase. Sequencing MaThg1 and transcript confirmed amber Translation led full-length, Pyl-containing, active enzyme as...
Histidine transfer RNA (tRNA) is unique among tRNA species as it carries an additional nucleotide at its 5' terminus. This unusual G(-1) residue the major tRNA(His) identity element, and essential for recognition by cognate histidyl-tRNA synthetase to allow efficient His-tRNA(His) formation. In many organisms added post-transcriptionally part of maturation process. guanylyltransferase (Thg1) specifically adds guanylyate recognizing anticodon. Thg1 homologs from all three domains life have...
Abstract Heterozygous pathogenic variants in the histidyl‐tRNA synthetase ( HARS ) gene are associated with Charcot–Marie–Tooth (CMT) type 2W disease, classified as an axonal peripheral neuropathy. To date, at least 60 causing CMT symptoms have been identified seven different aminoacyl‐tRNA synthetases, eight being found catalytic domain of HARS. The genetic data clearly show a causative role synthetases CMT; however, cellular mechanisms leading to pathology can vary widely and unknown case...
PPO (protoporphyrinogen IX oxidase) catalyses the flavin-dependent six-electron oxidation of protogen IX) to form proto (protoporphyrin IX), a crucial step in haem and chlorophyll biosynthesis. The apparent K(m) value for wild-type tobacco PPO2 (mitochondrial PPO) was 1.17 muM, with V(max) 4.27 muM.min(-1).mg(-1) catalytic activity k(cat) 6.0 s(-1). Amino acid residues that appear important substrate binding crystal structure-based model docked active site were interrogated by site-directed...
Christina Z. Chung, David Hyung Suk Jo and Ilka U. Heinemann Department of Biochemistry, The University Western Ontario, London, Ontario N6A 5C1, Canada Corresponding author: ilka.heinemann{at}uwo.ca
The phosphoinositide-3-kinase (PI3K)/AKT pathway regulates cell survival and is over-activated in most human cancers, including ovarian cancer. Following growth factor stimulation, AKT1 activated by phosphorylation at T308 S473. Disruption of the signaling sufficient to inhibit epithelial-mesenchymal transition epithelial cancer (EOC) cells. In metastatic disease, adherent EOC cells a dormant spheroid state, characterized previously low S473 AKT1. We confirmed this finding observed that was...
ABSTRACT The methanogenic archaeon Methanosarcina barkeri synthesizes protoheme via precorrin-2, which is formed from uroporphyrinogen III in two consecutive methylation reactions utilizing S -adenosyl- l -methionine. existence of this pathway, previously exclusively found the sulfate-reducing δ-proteobacterium Desulfovibrio vulgaris , was demonstrated for M. incorporation methyl groups methionine into protoheme.
During haem and chlorophyll biosynthesis, flavin-dependent protoporphyrinogen IX oxidase catalyses the six-electron oxidation of to form protoporphyrin IX. In following step, iron is inserted into by ferrochelatase. Based on solved crystal structures these enzymes, an in silico model for a complex between two enzymes was proposed protect highly photoreactive intermediate The existence this verified independent techniques. First, co-immunoprecipitation experiments using antibodies directed...
The identity of the histidine specific transfer RNA (tRNA His ) is largely determined by a unique guanosine residue at position −1. In eukaryotes and archaea, tRNA guanylyltransferase (Thg1) catalyzes 3′–5′ addition G to 5′‐terminus . Here, we show that Thg1 also occurs in bacteria. We demonstrate vitro activity for recombinant enzymes from two bacteria Bacillus thuringiensis Myxococcus xanthus provide closer investigation several archaeal Thg1. reaction mechanism prokaryotic differs...
Abstract Aminoacyl-tRNA synthetases are indispensable enzymes in all cells, ensuring the correct pairing of amino acids to their cognate tRNAs maintain translation fidelity. Autosomal dominant mutations V133F and Y330C histidyl-tRNA synthetase (HARS) cause genetic disorder Charcot-Marie-Tooth type 2W (CMT2W). Treatments currently restricted symptom relief, with no therapeutic available that targets disease. We previously found histidine supplementation alleviated phenotypic defects a...
Significance Template-dependent RNA and DNA polymerization is a vital reaction in the cell believed to occur exclusively forward direction (5′-3′), which poses significant challenges in, for example, lagging strand synthesis. Although cells are mostly limited unidirectional polymerization, we find that reverse structurally chemically possible utilizing same structural core, conserved palm domain of canonical polymerases. The structure unique nucleotide polymerase-tRNA complex revealed...