Search results for "subtil"
showing 10 items of 108 documents
Commensal Bacterium Rothia aeria Degrades and Detoxifies Gluten via a Highly Effective Subtilisin Enzyme
2020
Celiac disease is characterized by a chronic immune-mediated inflammation of the small intestine, triggered by gluten contained in wheat, barley, and rye. Rothia aeria, a gram-positive natural colonizer of the oral cavity and the upper digestive tract is able to degrade and detoxify gluten in vitro. The objective of this study was to assess gluten-degrading activity of live and dead R. aeria bacteria in vitro, and to isolate the R. aeria gluten-degrading enzyme. Methods: After an overnight fast, Balb/c mouse were fed a 1 g pellet of standard chow containing 50% wheat (and 4% gliadin) with or without 1.6 ×
PCSK7 gene variation bridges atherogenic dyslipidemia with hepatic inflammation in NAFLD patients
2019
Dyslipidemia and altered iron metabolism are typical features of nonalcoholic fatty liver disease (NAFLD). Proprotein convertase subtilisin/kexin type 7 (PCSK7) gene variation has been associated with circulating lipids and liver damage during iron overload. The aim of this study was to examine the impact of the PCSK7 rs236918 variant on NAFLDrelated traits in 1,801 individuals from the Liver Biopsy Cohort (LBC), 500,000 from the UK Biobank Cohort (UKBBC), and 4,580 from the Dallas Heart Study (DHS). The minor PCSK7 rs236918 C allele was associated with higher triglycerides, aminotransferases, and hepatic inflammation in the LBC (P < 0.05) and with hypercholesterolemia and liver disease …
Sensing of O 2 and nitrate by bacteria: alternative strategies for transcriptional regulation of nitrate respiration by O 2 and nitrate
2020
Many bacteria are able to use O2 and nitrate as alternative electron acceptors for respiration. Strategies for regulation in response to O2 and nitrate can vary considerably. In the paradigmatic system of E. coli (and γ-proteobacteria), regulation by O2 and nitrate is established by the O2 -sensor FNR and the two-component system NarX-NarL (for nitrate regulation). Expression of narGHJI is regulated by the binding of FNR and NarL to the promoter. A similar strategy by individual regulation in response to O2 and nitrate is verified in many genera by the use of various types of regulators. Otherwise, in the soil bacteria Bacillus subtilis (Firmicutes) and Streptomyces (Actinobacteria), nitrat…
Direct pathway cloning and expression of the radiosumin biosynthetic gene cluster
2023
Radiosumins are a structurally diverse family of low molecular weight natural products that are produced by cyanobacteria and exhibit potent serine protease inhibition. Members of this family are dipeptides characterized by the presence of two similar non-proteinogenic amino acids. Here we used a comparative bioinformatic analysis to identify radiosumin biosynthetic gene clusters from the genomes of 13 filamentous cyanobacteria. We used direct pathway cloning to capture and express the entire 16.8 kb radiosumin biosynthetic gene cluster from Dolichospermum planctonicum UHCC 0167 in Escherichia coli. Bioinformatic analysis demonstrates that radiosumins represent a new group of chorismate-der…
Hepatic and circulating levels of PCSK9 in morbidly obese patients: Relation with severity of liver steatosis
2020
Non-alcoholic fatty liver disease (NAFLD) is becoming the main cause of liver disease in Western countries, especially in morbidly obese patients (MOPs). The proprotein convertase subtilisin/kexin type 9 (PCSK9) has been recently studied because of its possible involvement in the pathogenesis of NAFLD, but its role, at least in MOPs, is still controversial. The aim of this study was to clarify the correlation between the circulating levels of the PCSK9 protein (cPCSK9) and its hepatic expression with the severity of liver damage in a population of MOPs with NAFLD undergoing bariatric surgery. PCSK9 mRNA was positively correlated with FASN, PPARγ and PPARα mRNAs, while no significant differe…
The Low-Affinity ATP Binding Site of the Escherichia coli SecA Dimer Is Localized at the Subunit Interface
1997
The homodimeric SecA protein is the ATP-dependent force generator in the Escherichia coli precursor protein translocation cascade. SecA contains two essential nucleotide binding sites (NBSs), i.e., NBS1 and NBS2 that hind ATP with high and low affinity, respectively. The photoactivatable bifunctional cross-linking agent 3'-arylazido-8-azidoadenosine 5'-triphosphate (diN(3)ATP) was used to investigate the spatial arrangement of the nucleotide binding sites of SecA, DiN(3)ATP is an authentic ATP analogue as it supports SecA-dependent precursor protein translocation and translocation ATPase, UV-induced photo-cross-linking of the diN(3)ATP-bound SecA results in the formation of stable dimeric s…
Antagonism of the endophytic Bacillus subtilis strain AG1 to fungal pathogens that cause tracheomycotic deterioration of wine wood
2008
Grapevine trunk diseases can determine considerable losses in the worldwide wine industry. Symptoms of wood diseases are dead spurs, arms, cordons and same times vine death, due to cankers in the vascular tissue (Pascoe, 2000). Recent research has also showed a recrudescence either of escadisease or decay by Verticilliumdahliae and the occurrence of new wood alterations (Botryosphaeriarhodina; Mugnai et al., 1999; Wood et al., 2005; Bonfiglioliet al., 2007). Last investigations, carried out in Sicilian vineyards on fungi associated with xilematic“esca”symptoms, revealed the occurrence of genus Bacillusin wood tissues. A spore-producer Gram-positive bacterial isolate, named AG1, was identifi…
The Agr communication system provides a benefit to the populations of Listeria monocytogenes in soil
2014
International audience; In this study, we investigated whether the Agr communication system of the pathogenic bacterium Listeria monocytogenes was involved in adaptation and competitiveness in soil. Alteration of the ability to communicate, either by deletion of the gene coding the response regulator AgrA (response-negative mutant) or the signal pro-peptide AgrD (signal-negative mutant), did not affect population dynamics in soil that had been sterilized but survival was altered in biotic soil suggesting that the Agr system of L. monocytogenes was involved to face the complex soil biotic environment. This was confirmed by a set of co-incubation experiments. The fitness of the response-negat…
Direct investigation of viscosity of an atypical inner membrane of Bacillus spores: A molecular rotor/FLIM study
2013
Abstract We utilize the fluorescent molecular rotor Bodipy-C12 to investigate the viscoelastic properties of hydrophobic layers of bacterial spores Bacillus subtilis. The molecular rotor shows a marked increase in fluorescence lifetime, from 0.3 to 4 ns, upon viscosity increase from 1 to 1500 cP and can be incorporated into the hydrophobic layers within the spores from dormant state through to germination. We use fluorescence lifetime imaging microscopy to visualize the viscosity inside different compartments of the bacterial spore in order to investigate the inner membrane and relate its compaction to the extreme resistance observed during exposure of spores to toxic chemicals. We demonstr…
Hybrid Quantum Mechanics/Molecular Mechanics Simulations with Two-Dimensional Interpolated Corrections: Application to Enzymatic Processes
2006
Hybrid quantum mechanics/molecular mechanics (QM/MM) techniques are widely used to study chemical reactions in large systems. Because of the computational cost associated with the high dimensionality of these systems, the quantum description is usually restricted to low-level methods, such as semiempirical Hamiltonians. In some cases, the description obtained at this computational level is quite poor and corrections must be considered. We here propose a simple but efficient way to include higher-level corrections to be used in potential energy surface explorations and in the calculation of potentials of mean force. We evaluate a correction energy term as the difference between a high-level …