Base de dados : MEDLINE Pesquisa : B03.440.450.900.859.225 [Categoria DeCS] Referências encontradas : 7382 [refinar] Mostrando: 1 .. 10   no formato [Detalhado]

página 1 de 739

ir para página

1 / 7382

MEDLINE

seleciona para imprimir Fotocópia Texto completo

[PMID]: 28461445 [Au] Autor: Yamamoto S; Ohnishi M [Ad] Endereço: Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan yshouji@nih.go.jp. [Ti] Título: Glucose-Specific Enzyme IIA of the Phosphoenolpyruvate:Carbohydrate Phosphotransferase System Modulates Chitin Signaling Pathways in Vibrio cholerae. [So] Source: J Bacteriol;199(18), 2017 09 15. [Is] ISSN: 1098-5530 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: In , the genes required for chitin utilization and natural competence are governed by the chitin-responsive two-component system (TCS) sensor kinase ChiS. In the classical TCS paradigm, a sensor kinase specifically phosphorylates a cognate response regulator to activate gene expression. However, our previous genetic study suggested that ChiS stimulates the non-TCS transcriptional regulator TfoS by using mechanisms distinct from classical phosphorylation reactions (S. Yamamoto, J. Mitobe, T. Ishikawa, S. N. Wai, M. Ohnishi, H. Watanabe, and H. Izumiya, Mol Microbiol 91:326-347, 2014, https://doi.org/10.1111/mmi.12462). TfoS specifically activates the transcription of , encoding a small regulatory RNA essential for competence gene expression. Whether ChiS and TfoS interact directly remains unknown. To determine if other factors mediate the communication between ChiS and TfoS, we isolated transposon mutants that turned off :: expression but possessed intact and genes. We demonstrated an unexpected association of chitin-induced signaling pathways with the glucose-specific enzyme IIA (EIIA ) of the phosphoenolpyruvate:carbohydrate phosphotransferase system (PTS) for carbohydrate uptake and catabolite control of gene expression. Genetic and physiological analyses revealed that dephosphorylated EIIA inactivated natural competence and transcription. Chitin-induced expression of the operon, which is required for chitin transport and catabolism, was also repressed by dephosphorylated EIIA Furthermore, the regulation of and expression by EIIA was dependent on ChiS and intracellular levels of ChiS were not affected by disruption of the gene encoding EIIA These results define a previously unknown connection between the PTS and chitin signaling pathways in and suggest a strategy whereby this bacterium can physiologically adapt to the existing nutrient status. The EIIA protein of the PTS coordinates a wide variety of physiological functions with carbon availability. In this report, we describe an unexpected association of chitin-activated signaling pathways in with EIIA The signaling pathways are governed by the chitin-responsive TCS sensor kinase ChiS and lead to the induction of chitin utilization and natural competence. We show that dephosphorylated EIIA inhibits both signaling pathways in a ChiS-dependent manner. This inhibition is different from classical catabolite repression that is caused by lowered levels of cyclic AMP. This work represents a newly identified connection between the PTS and chitin signaling pathways in and suggests a strategy whereby this bacterium can physiologically adapt to the existing nutrient status. [Mh] Termos MeSH primário: Quitina/metabolismo Regulação Bacteriana da Expressão Gênica Sistema Fosfotransferase de Açúcar do Fosfoenolpiruvato/metabolismo Transdução de Sinais Vibrio cholerae/genética Vibrio cholerae/metabolismo [Mh] Termos MeSH secundário: Elementos de DNA Transponíveis Redes Reguladoras de Genes Mutagênese Insercional [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (DNA Transposable Elements); 1398-61-4 (Chitin); EC 2.7.1.- (Phosphoenolpyruvate Sugar Phosphotransferase System) [Em] Mês de entrada: 1708 [Cu] Atualização por classe: 180306 [Lr] Data última revisão: 180306 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 170503 [St] Status: MEDLINE

2 / 7382

MEDLINE

seleciona para imprimir Fotocópia Texto completo

[PMID]: 29111407 [Au] Autor: Chahorm K; Prakitchaiwattana C [Ad] Endereço: Department of Food Technology, Faculty of Science, Chulalongkorn University, Patumwan, Bangkok 10330, Thailand. [Ti] Título: Application of Reverse Transcriptase-PCR-DGGE as a rapid method for routine determination of Vibrio spp. in foods. [So] Source: Int J Food Microbiol;264:46-52, 2018 Jan 02. [Is] ISSN: 1879-3460 [Cp] País de publicação: Netherlands [La] Idioma: eng [Ab] Resumo: The aim of this research was to evaluate the feasibility of PCR-DGGE and Reverse Transcriptase-PCR-DGGE techniques for rapid detection of Vibrio species in foods. Primers GC567F and 680R were initially evaluated for amplifying DNA and cDNA of ten references Vibrio species by PCR method. The GC-clamp PCR amplicons were separated according to their sequences by the DGGE using 10% (w/v) polyacrylamide gel containing 45-70% urea and formamide denaturants. Two pair of Vibrio species, which could not be differentiated on the gel, was Vibrio fluvialis - Vibrio furnissii and Vibrio parahaemolyticus - Vibrio harveyi. To determine the detection limit, in the community of 10 reference strains containing the same viable population, distinct DNA bands of 3 species; Vibrio cholerae, Vibrio mimicus and Vibrio alginolyticus were consistently observed by PCR-DGGE technique. In fact, 5 species; Vibrio cholerae, Vibrio mimicus, Vibrio alginolyticus, Vibrio parahaemolyticus and Vibrio fluvialis consistently observed by Reverse Transcriptase-PCR-DGGE. In the community containing different viable population increasing from 10 to 10 CFU/mL, PCR-DGGE analysis only detected the two most prevalent species, while RT-PCR-DGGE detected the five most prevalent species. Therefore, Reverse Transcriptase-PCR-DGGE was also selected for detection of various Vibrio cell conditions, including viable cell (VC), injured cells from frozen cultures (IVC) and injured cells from frozen cultures with pre-enrichment (PIVC). It was found that cDNA band of all cell conditions gave the same migratory patterns, except that multiple cDNA bands of Plesiomonas shigelloides under IVC and PIVC conditions were found. When Reverse Transcriptase-PCR-DGGE was used for detecting Vibrio parahaemolyticus in the pathogen-spiked food samples, Vibrio parahaemolyticus could be detected in the spiked samples containing at least 10 CFU/g of this pathogen. The results obtained also corresponded to standard method (USFDA, 2004). In comparison with the detection of the Vibrio profiles in fourteen food samples using standard method, Reverse Transcriptase-PCR-DGGE resulted in 100%, 75% and 50% similarity in 3, 1 and 6 food samples, respectively. [Mh] Termos MeSH primário: Eletroforese em Gel de Gradiente Desnaturante/métodos Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos Vibrio alginolyticus/genética Vibrio cholerae/genética Vibrio mimicus/genética Vibrio parahaemolyticus/genética [Mh] Termos MeSH secundário: Primers do DNA/genética Microbiologia de Alimentos/métodos Técnicas de Amplificação de Ácido Nucleico/métodos Reação em Cadeia da Polimerase/métodos DNA Polimerase Dirigida por RNA Vibrio alginolyticus/classificação Vibrio alginolyticus/isolamento & purificação Vibrio cholerae/classificação Vibrio cholerae/isolamento & purificação Vibrio mimicus/classificação Vibrio mimicus/isolamento & purificação Vibrio parahaemolyticus/classificação Vibrio parahaemolyticus/isolamento & purificação [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (DNA Primers); EC 2.7.7.49 (RNA-Directed DNA Polymerase) [Em] Mês de entrada: 1802 [Cu] Atualização por classe: 180226 [Lr] Data última revisão: 180226 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 171108 [St] Status: MEDLINE

3 / 7382

MEDLINE

seleciona para imprimir Fotocópia Texto completo

[PMID]: 29326272 [Au] Autor: Zhao W; Caro F; Robins W; Mekalanos JJ [Ti] Título: Antagonism toward the intestinal microbiota and its effect on virulence. [So] Source: Science;359(6372):210-213, 2018 01 12. [Is] ISSN: 1095-9203 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: The bacterial type VI secretion system (T6SS) is a nanomachine that delivers toxic effector proteins into target cells, killing them. In mice, we found that the T6SS attacks members of the host commensal microbiota in vivo, facilitating the pathogen's colonization of the gut. This microbial antagonistic interaction drives measurable changes in the pathogenicity of through enhanced intestinal colonization, expression of bacterial virulence genes, and activation of host innate immune genes. Because ablation of mouse commensals by this enteric pathogen correlated with more severe diarrheal symptoms, we conclude that antagonism toward the gut microbiota could improve the fitness of as a pathogen by elevating its transmission to new susceptible hosts. [Mh] Termos MeSH primário: Antibiose Cólera/microbiologia Microbioma Gastrointestinal/fisiologia Sistemas de Secreção Tipo VI/metabolismo Vibrio cholerae/fisiologia Vibrio cholerae/patogenicidade [Mh] Termos MeSH secundário: Animais Cólera/imunologia Cólera/metabolismo Citocinas/genética Citocinas/metabolismo Escherichia coli/crescimento & desenvolvimento Regulação da Expressão Gênica Regulação Bacteriana da Expressão Gênica Aptidão Genética Intestinos/imunologia Intestinos/metabolismo Intestinos/microbiologia Camundongos Mutação Simbiose Transcrição Genética Sistemas de Secreção Tipo VI/genética Vibrio cholerae/genética Vibrio cholerae/crescimento & desenvolvimento Virulência [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL [Nm] Nome de substância: 0 (Cytokines); 0 (Type VI Secretion Systems) [Em] Mês de entrada: 1802 [Cu] Atualização por classe: 180207 [Lr] Data última revisão: 180207 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 180113 [St] Status: MEDLINE [do] DOI: 10.1126/science.aap8775

4 / 7382

MEDLINE

seleciona para imprimir Fotocópia Texto completo

[PMID]: 27773473 [Au] Autor: Levinson KJ; Baranova DE; Mantis NJ [Ad] Endereço: Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY 12208, United States; Department of Biomedical Sciences, University at Albany, Albany, NY 12208, United States. [Ti] Título: A monoclonal antibody that targets the conserved core/lipid A region of lipopolysaccharide affects motility and reduces intestinal colonization of both classical and El Tor Vibrio cholerae biotypes. [So] Source: Vaccine;34(48):5833-5836, 2016 11 21. [Is] ISSN: 1873-2518 [Cp] País de publicação: Netherlands [La] Idioma: eng [Ab] Resumo: Vibrio cholerae is the causative agent of cholera, an acute diarrheal disease that remains endemic in many parts of the world. The mechanisms underlying immunity to cholera remain poorly defined, though it is increasingly clear that protection is associated with antibodies against lipopolysaccharide (LPS). Here we report that ZAC-3, a monoclonal antibody against the core/lipid A region of V. cholerae LPS is a potent inhibitor of V. cholerae flagellum-based motility in viscous and liquid environments. ZAC-3 arrested motility of the classical Ogawa strain O395, as well as the El Tor Inaba strain C6706. In addition, we demonstrate, in the neonatal mouse model, that ZAC-3 IgG and Fab fragments significantly reduced the ability of both V. cholerae strains O395 and C6706 to colonize the intestinal epithelium, revealing the potential of antibodies against the core/lipid A to contribute to immunity across biotypes, possibly through a mechanism involving motility arrest. [Mh] Termos MeSH primário: Anticorpos Monoclonais/imunologia Cólera/microbiologia Cólera/prevenção & controle Lipídeo A/imunologia Vibrio cholerae/imunologia [Mh] Termos MeSH secundário: Animais Animais Recém-Nascidos Anticorpos Antibacterianos/imunologia Anticorpos Monoclonais/administração & dosagem Antígenos de Bactérias/imunologia Técnicas de Tipagem Bacteriana Modelos Animais de Doenças Flagelos/efeitos dos fármacos Flagelos/fisiologia Fragmentos Fab das Imunoglobulinas/administração & dosagem Fragmentos Fab das Imunoglobulinas/imunologia Imunoglobulina G/administração & dosagem Imunoglobulina G/imunologia Mucosa Intestinal/imunologia Mucosa Intestinal/microbiologia Lipídeo A/química Camundongos Movimento Vibrio cholerae/efeitos dos fármacos [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL [Nm] Nome de substância: 0 (Antibodies, Bacterial); 0 (Antibodies, Monoclonal); 0 (Antigens, Bacterial); 0 (Immunoglobulin Fab Fragments); 0 (Immunoglobulin G); 0 (Lipid A) [Em] Mês de entrada: 1712 [Cu] Atualização por classe: 180206 [Lr] Data última revisão: 180206 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 161025 [St] Status: MEDLINE

5 / 7382

MEDLINE

seleciona para imprimir Fotocópia

[PMID]: 29369558 [Au] Autor: Smirnova NI; Kul'shan' TA; Baranikhina EY; Krasnov YM; Agafonov DA; Kutyrev VV [Ti] Título: [Genome structure and origin of nontoxigenic strains of Vibrio cholerae of El Tor biovar with different epidemiological significance]. [So] Source: Genetika;52(9):1029-41, 2016 Sep. [Is] ISSN: 0016-6758 [Cp] País de publicação: Russia (Federation) [La] Idioma: rus [Ab] Resumo: Intraspecies genetic differentiation of nontoxigenic strains of Vibrio cholerae of El Tor biovar containing one of the key pathogenicity genes, tcpA, is studied along with the phylogenetic relationships between these strains and toxigenic isolates. Comparative analysis of the whole genome nucleotide sequences demonstrates for the first time that ctxA ­ tcpA + strains vary considerably and can be clustered into two separate groups, the CTXφ­RS1φ +VPI+VSP+/CTXφ­RS1φ­VPI+VSP+ isolates and the CTXφ­RS1φ­VPI+VSP­ isolates, differing in their epidemiological significance. In the course of model experiments, it is established that nontoxigenic potentially epidemic CTXφ­RS1φ +VPI+VSP+/CTXφ­RS1φ­VPI+VSP+ isolates are derivatives of toxigenic strains. The results of whole genome SNP analysis of 35 Vibrio cholerae strains confirm these data and indicate genetic remoteness of nontoxigenic CTXφ­RS1φ­VPI+VSP­ strains both from the potentially epidemic strains and from the toxigenic isolates. It is found that the genomes of the CTXφ­RS1φ­VPI+VSP­ strains contain unique SNPs which are characteristic of them alone. The new data on the structure of the genome of nontoxigenic strains with different epidemiological significance may be further used for their genetic differentiation. [Mh] Termos MeSH primário: Genoma Bacteriano Genótipo Polimorfismo de Nucleotídeo Único Vibrio cholerae/genética [Mh] Termos MeSH secundário: Vibrio cholerae/patogenicidade [Pt] Tipo de publicação: JOURNAL ARTICLE [Em] Mês de entrada: 1802 [Cu] Atualização por classe: 180205 [Lr] Data última revisão: 180205 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 180126 [St] Status: MEDLINE

6 / 7382

MEDLINE

seleciona para imprimir Fotocópia Texto completo

[PMID]: 29350941 [Au] Autor: Kalziqi A; Yanni D; Thomas J; Ng SL; Vivek S; Hammer BK; Yunker PJ [Ad] Endereço: School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA. [Ti] Título: Immotile Active Matter: Activity from Death and Reproduction. [So] Source: Phys Rev Lett;120(1):018101, 2018 Jan 05. [Is] ISSN: 1079-7114 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: Unlike equilibrium atomic solids, biofilms-soft solids composed of bacterial cells-do not experience significant thermal fluctuations at the constituent level. However, living cells stochastically reproduce and die, provoking a mechanical response. We investigate the mechanical consequences of cellular death and reproduction by measuring surface-height fluctuations of biofilms containing two mutually antagonistic strains of Vibrio cholerae that kill one another on contact via the type VI secretion system. While studies of active matter typically focus on activity via constituent mobility, here, activity is mediated by reproduction and death events in otherwise immobilized cells. Biofilm surface topography is measured in the nearly homeostatic limit via white light interferometry. Although biofilms are far from equilibrium systems, measured surface-height fluctuation spectra resemble the spectra of thermal permeable membranes but with an activity-mediated effective temperature, as predicted by Risler, Peilloux, and Prost [Phys. Rev. Lett. 115, 258104 (2015)PRLTAO0031-900710.1103/PhysRevLett.115.258104]. By comparing the activity of killer strains of V. cholerae with that of genetically modified strains that cannot kill each other and validating with individual-based simulations, we demonstrate that extracted effective temperatures increase with the amount of death and reproduction and that death and reproduction can fluidize biofilms. Together, these observations demonstrate the unique physical consequences of activity mediated by death and reproduction events. [Mh] Termos MeSH primário: Biofilmes Vibrio cholerae [Mh] Termos MeSH secundário: Proteínas de Bactérias Morte Celular Regulação Bacteriana da Expressão Gênica Vibrio cholerae/crescimento & desenvolvimento Vibrio cholerae/fisiologia [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Bacterial Proteins) [Em] Mês de entrada: 1802 [Cu] Atualização por classe: 180205 [Lr] Data última revisão: 180205 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 180120 [St] Status: MEDLINE [do] DOI: 10.1103/PhysRevLett.120.018101

7 / 7382

MEDLINE

seleciona para imprimir Fotocópia Texto completo

[PMID]: 29231751 [Au] Autor: Angeli A; Del Prete S; Osman SM; Alasmary FAS; AlOthman Z; Donald WA; Capasso C; Supuran CT [Ad] Endereço: a Dipartimento Neurofarba, Sezione di Scienze Farmaceutiche e Nutraceutiche , Università degli Studi di Firenze , Florence , Italy. [Ti] Título: Activation studies of the α- and ß-carbonic anhydrases from the pathogenic bacterium Vibrio cholerae with amines and amino acids. [So] Source: J Enzyme Inhib Med Chem;33(1):227-233, 2018 Dec. [Is] ISSN: 1475-6374 [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: The α- and ß-class carbonic anhydrases (CAs, EC 4.2.1.1) from the pathogenic bacterium Vibrio cholerae, VchCAα, and VchCAß, were investigated for their activation with natural and non-natural amino acids and amines. The most effective VchCAα activators were L-tyrosine, histamine, serotonin, and 4-aminoethyl-morpholine, which had K s in the range of 8.21-12.0 µM. The most effective VchCAß activators were D-tyrosine, dopamine, serotonin, 2-pyridyl-methylamine, 2-aminoethylpyridine, and 2-aminoethylpiperazine, which had K s in the submicromolar - low micromolar range (0.18-1.37 µM). The two bacterial enzymes had very different activation profiles with these compounds, between each other, and in comparison to the human isoforms hCA I and II. Some amines were selective activators of VchCAß, including 2-pyridylmethylamine (K of 180 nm for VchCAß, and more than 20 µM for VchCAα and hCA I/II). The activation of CAs from bacteria, such as VchCAα/ß has not been considered previously for possible biomedical applications. It would be of interest to study in more detail the extent that CA activators are implicated in the virulence and colonisation of the host by such pathogenic bacteria, which for Vibrio cholerae, is highly dependent on the bicarbonate concentration and pH in the surrounding tissue. [Mh] Termos MeSH primário: Aminas/farmacologia Aminoácidos/farmacologia Inibidores da Anidrase Carbônica/farmacologia Anidrases Carbônicas/metabolismo Vibrio cholerae/enzimologia [Mh] Termos MeSH secundário: Aminas/síntese química Aminas/química Aminoácidos/síntese química Aminoácidos/química Inibidores da Anidrase Carbônica/síntese química Inibidores da Anidrase Carbônica/química Relação Dose-Resposta a Droga Seres Humanos Estrutura Molecular Relação Estrutura-Atividade Vibrio cholerae/patogenicidade [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Amines); 0 (Amino Acids); 0 (Carbonic Anhydrase Inhibitors); EC 4.2.1.1 (Carbonic Anhydrases) [Em] Mês de entrada: 1712 [Cu] Atualização por classe: 171221 [Lr] Data última revisão: 171221 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 171213 [St] Status: MEDLINE [do] DOI: 10.1080/14756366.2017.1412316

8 / 7382

MEDLINE

seleciona para imprimir Fotocópia Texto completo

[PMID]: 28464377 [Au] Autor: Midgett CR; Almagro-Moreno S; Pellegrini M; Taylor RK; Skorupski K; Kull FJ [Ad] Endereço: Department of Chemistry, Dartmouth College, Hanover, NH, 03755, USA. [Ti] Título: Bile salts and alkaline pH reciprocally modulate the interaction between the periplasmic domains of Vibrio cholerae ToxR and ToxS. [So] Source: Mol Microbiol;105(2):258-272, 2017 Jul. [Is] ISSN: 1365-2958 [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: ToxR is a transmembrane transcription factor that is essential for virulence gene expression and human colonization by Vibrio cholerae. ToxR requires its operon partner ToxS, a periplasmic integral membrane protein, for full activity. These two proteins are thought to interact through their respective periplasmic domains, ToxRp and ToxSp. In addition, ToxR is thought to be responsive to various environmental cues, such as bile salts and alkaline pH, but how these factors influence ToxR is not yet understood. Using NMR and reciprocal pull down assays, we present the first direct evidence that ToxR and ToxS physically interact. Furthermore, using NMR and DSF, it was shown that the bile salts cholate and chenodeoxycholate interact with purified ToxRp and destabilize it. Surprisingly, bile salt destabilization of ToxRp enhanced the interaction between ToxRp and ToxSp. In contrast, alkaline pH, which is one of the factors that leads to ToxR proteolysis, decreased the interaction between ToxRp and ToxSp. Taken together, these data suggest a model whereby bile salts or other detergents destabilize ToxR, increasing its interaction with ToxS to promote full ToxR activity. Subsequently, as V. cholerae alkalinizes its environment in late stationary phase, the interaction between the two proteins decreases, allowing ToxR proteolysis to proceed. [Mh] Termos MeSH primário: Proteínas de Bactérias/genética Proteínas de Ligação a DNA/genética Proteínas de Membrana/genética Fatores de Transcrição/genética [Mh] Termos MeSH secundário: Proteínas de Bactérias/metabolismo Ácidos e Sais Biliares/metabolismo Proteínas de Ligação a DNA/metabolismo Regulação Bacteriana da Expressão Gênica/genética Concentração de Íons de Hidrogênio Proteínas de Membrana/metabolismo Óperon/genética Periplasma/metabolismo Domínios Proteicos/genética Proteólise Fatores de Transcrição/metabolismo Vibrio cholerae/genética Virulência/genética [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Bacterial Proteins); 0 (Bile Acids and Salts); 0 (DNA-Binding Proteins); 0 (Membrane Proteins); 0 (Transcription Factors); 0 (toxR protein, Vibrio cholerae); 135315-97-8 (ToxS protein, Vibrio cholerae) [Em] Mês de entrada: 1711 [Cu] Atualização por classe: 171128 [Lr] Data última revisão: 171128 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 170503 [St] Status: MEDLINE [do] DOI: 10.1111/mmi.13699

9 / 7382

MEDLINE

seleciona para imprimir Fotocópia Texto completo

[PMID]: 29065131 [Au] Autor: Fang X; Liang P; Raba DA; Rosas-Lemus M; Chakravarthy S; Tuz K; Juárez O [Ad] Endereço: Department of Biological Sciences, Illinois Institute of Technology, Chicago, Illinois, United States of America. [Ti] Título: Kinetic characterization of Vibrio cholerae ApbE: Substrate specificity and regulatory mechanisms. [So] Source: PLoS One;12(10):e0186805, 2017. [Is] ISSN: 1932-6203 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: ApbE is a member of a novel family of flavin transferases that incorporates flavin mononucleotide (FMN) to subunits of diverse respiratory complexes, which fulfill important homeostatic functions. In this work a detailed characterization of Vibrio cholerae ApbE physiologic activity, substrate specificity and pH dependency was carried out. The data obtained show novel characteristics of the regulation and function of this family. For instance, our experiments indicate that divalent cations are essential for ApbE function, and that the selectivity depends largely on size and the coordination sphere of the cation. Our data also show that ApbE regulation by pH, ADP and potassium is an important mechanism that enhances the adaptation, survival and colonization of V. cholerae in the small intestine. Moreover, studies of the pH-dependency of the activity show that the reaction is favored under alkaline conditions, with a pKa of 8.4. These studies, together with sequence and structure analysis allowed us to identify His257, which is absolutely conserved in the family, as a candidate for the residue whose deprotonation controls the activity. Remarkably, the mutant H257G abolished the flavin transfer activity, strongly indicating that this residue plays an important role in the catalytic mechanism of ApbE. [Mh] Termos MeSH primário: Proteínas de Bactérias/metabolismo Vibrio cholerae/metabolismo [Mh] Termos MeSH secundário: Cátions Bivalentes Cátions Monovalentes Concentração de Íons de Hidrogênio Cinética Especificidade por Substrato [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Bacterial Proteins); 0 (Cations, Divalent); 0 (Cations, Monovalent) [Em] Mês de entrada: 1711 [Cu] Atualização por classe: 171113 [Lr] Data última revisão: 171113 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 171025 [St] Status: MEDLINE [do] DOI: 10.1371/journal.pone.0186805

10 / 7382

MEDLINE

seleciona para imprimir Fotocópia Texto completo

[PMID]: 29048594 [Au] Autor: Marinier E; Zaheer R; Berry C; Weedmark KA; Domaratzki M; Mabon P; Knox NC; Reimer AR; Graham MR; Chui L; Patterson-Fortin L; Zhang J; Pagotto F; Farber J; Mahony J; Seyer K; Bekal S; Tremblay C; Isaac-Renton J; Prystajecky N; Chen J; Slade P; Van Domselaar G [Ad] Endereço: National Microbiology Laboratory, Public Health Agency of Canada, 1015 Arlington St, Winnipeg, MB R3E 3R2, Canada. [Ti] Título: Neptune: a bioinformatics tool for rapid discovery of genomic variation in bacterial populations. [So] Source: Nucleic Acids Res;45(18):e159, 2017 Oct 13. [Is] ISSN: 1362-4962 [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: The ready availability of vast amounts of genomic sequence data has created the need to rethink comparative genomics algorithms using 'big data' approaches. Neptune is an efficient system for rapidly locating differentially abundant genomic content in bacterial populations using an exact k-mer matching strategy, while accommodating k-mer mismatches. Neptune's loci discovery process identifies sequences that are sufficiently common to a group of target sequences and sufficiently absent from non-targets using probabilistic models. Neptune uses parallel computing to efficiently identify and extract these loci from draft genome assemblies without requiring multiple sequence alignments or other computationally expensive comparative sequence analyses. Tests on simulated and real datasets showed that Neptune rapidly identifies regions that are both sensitive and specific. We demonstrate that this system can identify trait-specific loci from different bacterial lineages. Neptune is broadly applicable for comparative bacterial analyses, yet will particularly benefit pathogenomic applications, owing to efficient and sensitive discovery of differentially abundant genomic loci. The software is available for download at: http://github.com/phac-nml/neptune. [Mh] Termos MeSH primário: Bactérias/genética Biologia Computacional/métodos Análise Mutacional de DNA/métodos Estudos de Associação Genética Técnicas Microbiológicas/métodos Análise de Sequência de DNA/métodos Software [Mh] Termos MeSH secundário: Bacillus anthracis/genética Regulação Bacteriana da Expressão Gênica Genoma Bacteriano Transcriptoma Vibrio cholerae/genética [Pt] Tipo de publicação: JOURNAL ARTICLE; VALIDATION STUDIES [Em] Mês de entrada: 1710 [Cu] Atualização por classe: 171031 [Lr] Data última revisão: 171031 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 171020 [St] Status: MEDLINE [do] DOI: 10.1093/nar/gkx702

---

página 1 de 739

ir para página

Refinar a pesquisa

Base de dados : MEDLINE

Formulário avançado

		Pesquisar	no campo
1			PalavrasDescritor de assuntoDescritor de assunto primárioLimitesAutorPalavras do títuloPalavras do resumoIdiomaPaís de publicaçãoNome de substânciaNome de pessoa como assuntoRevistaAssunto de RevistaISSNTipo de publicaçãoIdentificador únicoMês de entradaAno de publicaçãoTexto completoAtualização por classeCategoria DeCSCategoria DeCS explodidaCategoria CID-10SubSetsPais de AfiliaçãoAfiliaçãoAfiliação 2
2	and or and not		PalavrasDescritor de assuntoDescritor de assunto primárioLimitesAutorPalavras do títuloPalavras do resumoIdiomaPaís de publicaçãoNome de substânciaNome de pessoa como assuntoRevistaAssunto de RevistaISSNTipo de publicaçãoIdentificador únicoMês de entradaAno de publicaçãoTexto completoAtualização por classeCategoria DeCSCategoria DeCS explodidaCategoria CID-10SubSetsPais de AfiliaçãoAfiliaçãoAfiliação 2
3	and or and not		PalavrasDescritor de assuntoDescritor de assunto primárioLimitesAutorPalavras do títuloPalavras do resumoIdiomaPaís de publicaçãoNome de substânciaNome de pessoa como assuntoRevistaAssunto de RevistaISSNTipo de publicaçãoIdentificador únicoMês de entradaAno de publicaçãoTexto completoAtualização por classeCategoria DeCSCategoria DeCS explodidaCategoria CID-10SubSetsPais de AfiliaçãoAfiliaçãoAfiliação 2

Search engine: iAH v2.6 powered by WWWISIS

BIREME/OPAS/OMS - Centro Latino-Americano e do Caribe de Informação em Ciências da Saúde