Enzymes of the glyoxylate-bypass pathway are potential targets for the control of many human diseases caused by such pathogens as Mycobacteria and Leishmania. Isocitrate lyase catalyses the first committed step in this pathway and the structure of this tetrameric enzyme from Escherichia coli has been determined at 2.1 A resolution. E. coli isocitrate lyase, like the enzyme from other prokaryotes, is located in the cytoplasm, whereas in plants, protozoa, algae and fungi this enzyme is found localized in glyoxysomes. Comparison of the structure of the prokaryotic isocitrate lyase with that from the eukaryote Aspergillus nidulans reveals a different domain structure following the deletion of approximately 100 residues from the larger eukaryotic enzyme. Despite this, the active sites of the prokaryotic and eukaryotic enzymes are very closely related, including the apparent disorder of two equivalent segments of the protein that are known to be involved in a conformational change as part of the enzyme's catalytic cycle.
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http://dx.doi.org/10.1107/s0907444901008642 | DOI Listing |
Appl Biochem Biotechnol
March 2025
Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Madhya Marg, Sector 12, Chandigarh, 160012, India.
The metabolic enzyme ATP citrate lyase is overexpressed in several cancers and links glucose metabolism with de novo fatty acid synthesis pathway by catalyzing the conversion of citrate into acetyl CoA and oxaloacetate. Potassium hydroxycitrate, its natural inhibitor, exhibits anticancer activity; however, its use is limited due to low bioavailability. This study aims to improve the efficacy of hydroxycitrate by its encapsulation in bovine milk exosome surface conjugated with folate for targeting lung cancer cells.
View Article and Find Full Text PDFJ Biol Chem
February 2025
Department of Biochemistry, University of Cambridge, United Kingdom. Electronic address:
The 2-methylcitrate cycle (2-MCC) and the glyoxylate cycle are central metabolic pathways in Pseudomonas aeruginosa, enabling the organism to utilize organic acids such as propionate and acetate during infection. Here, we show that these cycles are linked through enzymatic redundancy, with isocitrate lyase (AceA) exhibiting secondary 2-methylisocitrate lyase (2-MICL) activity. Furthermore, we use a combination of structural analyses, enzyme kinetics, metabolomics, and targeted mutation of PrpB to demonstrate that whereas loss of PrpB function impairs growth on propionate, the promiscuous 2-MICL activity of AceA compensates for this by mitigating the accumulation of toxic 2-MCC intermediates.
View Article and Find Full Text PDFJ Agric Food Chem
March 2025
State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China.
Phenazine-1-carboxylic acid (PCA), as a broad-spectrum antifungal agent, showed significant resistance against the Apple Valsa canker caused by (). Therefore, it is of great importance to reveal the functions and mechanisms of PCA in plant pathogens, which would provide potential targets for crop disease control. In this study, we identified the major contribution of PCA in the resistance of subsp.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
March 2025
State Key Laboratory of Urban Water Resource and Environment, MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, China.
Building an artificial photosynthetic cell from scratch helps to understand the working mechanisms of chloroplasts. It is a challenge to achieve carbon fixation triggered by photosynthetic organelles in an artificial cell. ATP synthase and photosystem II (PSII) are purified and reconstituted onto the phospholipid membrane to fabricate photosynthetic organelles.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Centre for Tuberculosis Research, Tuberculosis Research Laboratory, Translational Health Science and Technology Institute, National Capital Region Biotech Science Cluster 3rd Milestone, Faridabad, Haryana 121001, India.
Itaconate, an abundant metabolite produced by macrophages upon interferon-γ stimulation, possesses both antibacterial and immunomodulatory properties. Despite its crucial role in immunity and antimicrobial control, its mechanism of action and dissimilation are poorly understood. Here, we demonstrate that infection of mice with increases itaconate levels in lung tissues.
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