Engineering the function of triterpene glucosyltransferases (GTs) is challenging due to the large size of the sugar acceptors. In this work, we identified a multifunctional glycosyltransferase AmGT8 catalyzing triterpene 3-/6-/2'-O-glycosylation from the medicinal plant Astragalus membranaceus. To engineer its regiospecificity, a small mutant library was built based on semi-rational design. Variants A394F, A394D, and T131V were found to catalyze specific 6-O, 3-O, and 2'-O glycosylation, respectively. The origin of regioselectivity of AmGT8 and its A394F variant was studied by molecular dynamics and hydrogen deuterium exchange mass spectrometry. Residue 394 is highly conserved as A/G and is critical for the regiospecificity of the C- and O-GTs TcCGT1 and GuGT10/14. Finally, astragalosides III and IV were synthesized by mutants A394F, T131V and P192E. This work reports biocatalysts for saponin synthesis and gives new insights into protein engineering of regioselectivity in plant GTs.
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http://dx.doi.org/10.1002/anie.202113587 | DOI Listing |
Microb Cell Fact
January 2025
National Center of Technology Innovation for Synthetic Biology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.
Background: Ogataea polymorpha, a non-conventional methylotrophic yeast, has demonstrated significant potential for heterologous protein expression and the production of high-value chemicals and biopharmaceuticals. However, the lack of precise and efficient genome editing tools severely hinders the construction of cell factories. Although the CARISP-Cas9 system has been established in Ogataea polymorpha, the gene editing efficiency, especially for multiple genes edition, needs to be further improved.
View Article and Find Full Text PDFBMC Bioinformatics
January 2025
Department of Applied Computer Science, University of Winnipeg, Winnipeg, MB, R3B 2E9, Canada.
Background: Comprehensively mapping the hierarchical structure of breast cancer protein communities and identifying potential biomarkers from them is a promising way for breast cancer research. Existing approaches are subjective and fail to take information from protein sequences into consideration. Deep learning can automatically learn features from protein sequences and protein-protein interactions for hierarchical clustering.
View Article and Find Full Text PDFNat Nanotechnol
January 2025
Department of Chemistry, University of Oxford, Oxford, UK.
Nanoscale photoswitchable proteins could facilitate precise spatiotemporal control of transmembrane communication and support studies in synthetic biology, neuroscience and bioelectronics. Here, through covalent modification of the α-haemolysin protein pore with arylazopyrazole photoswitches, we produced 'photopores' that transition between iontronic resistor and diode modes in response to irradiation at orthogonal wavelengths. In the diode mode, a low-leak OFF-state nanopore exhibits a reversible increase in unitary conductance of more than 20-fold upon irradiation at 365 nm.
View Article and Find Full Text PDFCardiovasc Toxicol
January 2025
Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, No. 250, Wuxing St., Taipei, 11031, Taiwan.
Ventricular arrhythmias (VAs) are major causes of sudden cardiac death in chronic kidney disease (CKD) patients. Indoxyl sulfate (IS) is one common uremic toxin found in CKD patients. This study investigated whether IS could induce VAs via increasing right ventricular outflow tract (RVOT) arrhythmogenesis.
View Article and Find Full Text PDFNat Plants
January 2025
National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China.
Arabidopsis PHOSPHATE 1 (AtPHO1) and its closest homologue AtPHO1;H1 are phosphate transporters that load phosphate into the xylem vessel for root-to-shoot translocation. AtPHO1 and AtPHO1;H1 are prototypical members of the unique SPX-EXS family, whose structural and molecular mechanisms remain elusive. In this study, we determined the cryogenic electron microscopy structure of AtPHO1;H1 binding with inorganic phosphate (Pi) and inositol hexakisphosphate in a closed conformation.
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