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Nature Communications Apr 2024Controlled assembly of a protein shell around a viral genome is a key step in the life cycle of many viruses. Here we report a strategy for regulating the co-assembly of...
Controlled assembly of a protein shell around a viral genome is a key step in the life cycle of many viruses. Here we report a strategy for regulating the co-assembly of nonviral proteins and nucleic acids into highly ordered nucleocapsids in vitro. By fusing maltose binding protein to the subunits of NC-4, an engineered protein cage that encapsulates its own encoding mRNA, we successfully blocked spontaneous capsid assembly, allowing isolation of the individual monomers in soluble form. To initiate RNA-templated nucleocapsid formation, the steric block can be simply removed by selective proteolysis. Analyses by transmission and cryo-electron microscopy confirmed that the resulting assemblies are structurally identical to their RNA-containing counterparts produced in vivo. Enzymatically triggered cage formation broadens the range of RNA molecules that can be encapsulated by NC-4, provides unique opportunities to study the co-assembly of capsid and cargo, and could be useful for studying other nonviral and viral assemblies.
Topics: Nucleocapsid; Cryoelectron Microscopy; Maltose-Binding Proteins; Virus Assembly; Capsid; RNA, Viral; Capsid Proteins; RNA, Messenger
PubMed: 38678040
DOI: 10.1038/s41467-024-47808-1 -
Microorganisms Apr 2024was primarily identified based on the characteristics of its conidia and several sequences. The fungus causes severe leaf spot disease on hairy vetch ( var. ) in Yunnan...
was primarily identified based on the characteristics of its conidia and several sequences. The fungus causes severe leaf spot disease on hairy vetch ( var. ) in Yunnan Province in China. The growth, sporulation, fungicide efficacy, and host range of the pathogen were evaluated to aid in disease management. Different types of culture media and carbon and nitrogen sources were used to evaluate the growth of Oatmeal, maltose, and potassium nitrate agar had a higher amount of sporulation. Difenoconazole (10%) was the most effective fungicide against the leaf disease caused by . In addition, foliar inoculation sprays were used to assess the host range of in six different plant species, including alfalfa ( L.), sainfoin ( Scop.), erect milkvetch ( Pall.), common vetch ( L.), red clover ( L.), and white clover ( L.). successfully infected these plants, indicating that it has a wider host range than hairy vetches.
PubMed: 38674710
DOI: 10.3390/microorganisms12040766 -
International Journal of Molecular... Apr 2024Membrane proteins constitute about 20% of the human proteome and play crucial roles in cellular functions. However, a complete understanding of their structure and...
Membrane proteins constitute about 20% of the human proteome and play crucial roles in cellular functions. However, a complete understanding of their structure and function is limited by their hydrophobic nature, which poses significant challenges in purification and stabilization. Detergents, essential in the isolation process, risk destabilizing or altering the proteins' native conformations, thus affecting stability and functionality. This study leverages single-particle cryo-electron microscopy to elucidate the structural nuances of membrane proteins, focusing on the SLAC1 bacterial homolog from (TehA) purified with diverse detergents, including n-dodecyl β-D-maltopyranoside (DDM), glycodiosgenin (GDN), β-D-octyl-glucoside (OG), and lauryl maltose neopentyl glycol (LMNG). This research not only contributes to the understanding of membrane protein structures but also addresses detergent effects on protein purification. By showcasing that the overall structural integrity of the channel is preserved, our study underscores the intricate interplay between proteins and detergents, offering insightful implications for drug design and membrane biology.
Topics: Cryoelectron Microscopy; Haemophilus influenzae; Bacterial Proteins; Detergents; Microscopy, Electron, Transmission; Membrane Proteins
PubMed: 38674110
DOI: 10.3390/ijms25084528 -
Pathogens (Basel, Switzerland) Apr 2024A novel coagulase-negative strain (H164) was isolated from soymilk in Taiwan. Comparative sequence analysis of the 16S rRNA gene revealed that the H164 strain is a...
A novel coagulase-negative strain (H164) was isolated from soymilk in Taiwan. Comparative sequence analysis of the 16S rRNA gene revealed that the H164 strain is a member of the genus . We used multilocus sequence analysis (MLSA) and phylogenomic analyses to demonstrate that the novel strain was closely related to , , , and . The average nucleotide identity and digital DNA-DNA hybridization values between H164 and its closest relatives were <95% and <70%, respectively. The H164 strain could also be distinguished from its closest relatives by the fermentation of -fructose, -maltose, -trehalose, and -mannitol, as well as by the activities of α-glucosidase and alkaline phosphatase. The major cellular fatty acids were C15:0 iso and C15:0 anteiso, and the predominant menaquinones were MK-7 and MK-8, respectively. The major cellular fatty acids and predominant menaquinones were C iso and C anteiso and MK-7 and MK-8, respectively. In conclusion, this strain represents a novel species, named sp. nov., with the type strain H164 (=BCRC 81404 = NBRC 116174).
PubMed: 38668298
DOI: 10.3390/pathogens13040343 -
Journal of Fungi (Basel, Switzerland) Mar 2024Sialidases (neuraminidases) catalyze the removal of terminal sialic acid residues from glycoproteins. Novel enzymes from non-clinical isolates are of increasing interest...
Sialidases (neuraminidases) catalyze the removal of terminal sialic acid residues from glycoproteins. Novel enzymes from non-clinical isolates are of increasing interest regarding their application in the food and pharmaceutical industry. The present study aimed to evaluate the participation of carbon catabolite repression (CCR) in the regulation of cold-active sialidase biosynthesis by the psychrotolerant fungal strain P29, isolated from Antarctica. The presence of glucose inhibited sialidase activity in growing and non-growing fungal mycelia in a dose- and time-dependent manner. The same response was demonstrated with maltose and sucrose. The replacement of glucose with glucose-6-phosphate also exerted CCR. The addition of cAMP resulted in the partial de-repression of sialidase synthesis. The CCR in the psychrotolerant strain P29 did not depend on temperature. Sialidase might be subject to glucose repression by both at 10 and 25 °C. The fluorescent assay using 4MU-Neu5Ac for enzyme activity determination under increasing glucose concentrations evidenced that CCR may have a regulatory role in sialidase production. The real-time RT-PCR experiments revealed that the sialidase gene was subject to glucose repression. To our knowledge, this is the first report that has studied the effect of CCR on cold-active sialidase, produced by an Antarctic strain.
PubMed: 38667912
DOI: 10.3390/jof10040241 -
Insects Apr 2024Alterative nutritional foods consumed by adult parasitoids play an important role in their fitness and ability to control pests because of food scarcity in many crops....
Alterative nutritional foods consumed by adult parasitoids play an important role in their fitness and ability to control pests because of food scarcity in many crops. While adult parasitoids feed on various sugars, they vary in their nutritional value for parasitoids. We assessed the effects of seven sugars (fructose, glucose, sucrose, trehalose, maltose, melezitose, and sorbitol) on the longevity, parasitism ability, parasitism behavior, and flight ability of , an important parasitoid of cotton aphids. We found that access to glucose, sucrose, or fructose, increased adult longevity more than the other sugars offered. All sugars except trehalose increased the parasitism rate to more than 50% compared to the starved control (only provided with water). We then compared parasitoid behaviors of wasps fed glucose, sucrose, or fructose to that of the starved control (with access only to water) and found that those fed spent more time either examining or attacking aphids than parasitoids in the control group, which spent more time walking or resting. Also, consumption of glucose, sucrose, or fructose also significantly improved the flight ability (the total flight distance, flight time, and average flight speed) of .
PubMed: 38667375
DOI: 10.3390/insects15040245 -
Frontiers in Microbiology 2024Lanzhou lily ( var. ) is an exclusive sweet lily variety indigenous to China, which is susceptible to bulbous rot caused by fungal infection during storage. This...
Lanzhou lily ( var. ) is an exclusive sweet lily variety indigenous to China, which is susceptible to bulbous rot caused by fungal infection during storage. This experiment tests the pathogenicity of the pure culture isolated from the diseased tissue was confirmed in accordance with Koch's postulates, and the pathomycetes were identified based on their morphological and molecular characteristics. Furthermore, the biological characteristics of the pathogens were investigated, followed by an evaluation of the antifungal effects of three plant essential oils against them. The results showed that two strains of fungi were isolated from Lanzhou lily rot, which were identified as Schl. and (Bain. Et sart.). In addition, the pathogenicity of these two strains of fungi was demonstrated that only induced rot with similar symptoms during the post-harvest storage period. The biological characteristics of indicated the potato maltose agar and lily dextrose agar were identified as the most suitable media. Sucrose was determined to be the optimal carbon source, while ammonium nitrate was found to be the best nitrogen source for the growth of . Mycelial growth and sporulation of occurred at an optimum pH value of 6. Total darkness facilitated mycelial growth and conidial germination. The ideal temperature for growth was found to be 28°C, while relative humidity did not significantly impact mycelial growth; however, a relative humidity of 55% was most favorable for spore production. Among the three essential oils tested, cinnamon essential oil displayed superior antifungal efficacy against , whereas angelica essential oil and tea tree essential oil also exhibited moderate inhibitory effects against this pathogen. This research provides valuable theoretical insights for disease control during the storage and transportation of Lanzhou lily.
PubMed: 38666262
DOI: 10.3389/fmicb.2024.1307966 -
International Journal of Systematic and... Apr 2024A novel bifidobacterium (designated F753-1) was isolated from the gut of honeybee (). Strain F753-1 was characterized using a polyphasic taxonomic approach. Strain...
A novel bifidobacterium (designated F753-1) was isolated from the gut of honeybee (). Strain F753-1 was characterized using a polyphasic taxonomic approach. Strain F753-1 was phylogenetically related to the type strains of , , , , and , having 98.4-99.8 % 16S rRNA gene sequence similarities. The phylogenomic tree indicated that strain F753-1 was most closely related to the type strains of and . Strain F753-1 had the highest average nucleotide identity (94.1-94.5 %) and digital DNA-DNA hybridization (56.3 %) values with Bin7N. Acid production from amygdalin, d-fructose, gentiobiose, d-mannose, maltose, sucrose and d-xylose, activity of -galactosidase, pyruvate utilization and hydrolysis of hippurate could differentiate strain F753-1 from CCUG 66113 and JCM 34586. Based upon the data obtained in the present study, a novel species, sp. nov., is proposed, and the type strain is F753-1 (=CCTCC AB 2023227=JCM 36562=LMG 33388).
Topics: Bees; Animals; RNA, Ribosomal, 16S; Phylogeny; Bifidobacterium; DNA, Bacterial; Nucleic Acid Hybridization; Sequence Analysis, DNA; Bacterial Typing Techniques; Fatty Acids; Base Composition; Gastrointestinal Microbiome
PubMed: 38661726
DOI: 10.1099/ijsem.0.006358 -
Food Chemistry Sep 2024The wine market has always faced the problem of fraud, including the addition of exogenous sugar solutions to grape musts to increase the final alcohol content. Since in...
The wine market has always faced the problem of fraud, including the addition of exogenous sugar solutions to grape musts to increase the final alcohol content. Since in some countries the practice of chaptalization is prohibited (except by adding concentrated must) it is necessary to broaden the analytical techniques that allow the identification of this type of fraud. The aim of this study was to define an NMR-based sugar profile of genuine grape must to set concentration limits for each sugar as parameters of authenticity. Glucose, fructose, together with eleven minor sugars were quantified in 82 genuine Italian grape musts, developing an analytical procedure based on highly selective chemical shift filters followed by TOCSY. Alongside the characteristic myo- and scyllo-inositol, significant contents of mannose, galactose, and trehalose were also found. Otherwise, maltose, rhamnose, arabinose, sucrose and lactose are present in lower concentrations and show great concentration variability.
Topics: Vitis; Magnetic Resonance Spectroscopy; Wine; Sugars; Fruit
PubMed: 38657517
DOI: 10.1016/j.foodchem.2024.139374 -
Bioresources and Bioprocessing Jan 2024The bioconversion of 4-hydroxy-2-keto acid derivatives via aldol condensation of formaldehyde and pyruvate has received substantial attention as potential source of...
The bioconversion of 4-hydroxy-2-keto acid derivatives via aldol condensation of formaldehyde and pyruvate has received substantial attention as potential source of chemicals for production of amino acids, hydroxy carboxylic acids, and chiral aldehydes. We developed an environmentally friendly biocatalyst consisting of a novel thermostable class II pyruvate aldolase from Deinococcus radiodurans with maltose-binding protein (MBP-DrADL), which has specific activity of 46.3 µmol min mg. Surprisingly, MBP-DrADL maintained over 60% of enzyme activity for 4 days at 50 to 65 °C, we used MBP-DrADL as the best candidate enzyme to produce 2-keto-4-hydroxybutyrate (2-KHB) from formaldehyde and pyruvate via aldol condensation. The optimum reaction conditions for 2-KHB production were 50 °C, pH 8.0, 5 mM Mg, 100 mM formaldehyde, and 200 mM pyruvate. Under these optimized conditions, MBP-DrADL produced 76.5 mM (8.94 g L) 2-KHB over 60 min with a volumetric productivity of 8.94 g L h and a specific productivity of 357.6 mg mg-enzyme h. Furthermore, 2-KHB production was improved by continuous addition of substrates, which produced approximately 124.8 mM (14.6 g L) of 2-KHB over 60 min with a volumetric productivity and specific productivity of 14.6 g L h and 583.4 mg mg-enzyme h, respectively. MBP-DrADL showed the highest specific productivity for 2-KHB production yet reported. Our study provides a highly efficient biocatalyst for the synthesis of 2-KHB and lays the foundation for large-scale production and application of high-value compounds from formaldehyde.
PubMed: 38647973
DOI: 10.1186/s40643-024-00727-x