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[PMID]:28461451
[Au] Autor:Li L; Jiang W; Lu Y
[Ad] Endereço:Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.
[Ti] Título:A Novel Two-Component System, GluR-GluK, Involved in Glutamate Sensing and Uptake in Streptomyces coelicolor.
[So] Source:J Bacteriol;199(18), 2017 09 15.
[Is] ISSN:1098-5530
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Two-component systems (TCSs), the predominant signal transduction pathways employed by bacteria, play important roles in physiological metabolism in Here, a novel TCS, GluR-GluK (encoded by ), which is located divergently from the operon encoding a glutamate uptake system, was identified as being involved in glutamate sensing and uptake as well as antibiotic biosynthesis in Under the condition of minimal medium (MM) supplemented with different concentrations of glutamate, deletion of the operon ( ) resulted in enhanced actinorhodin (ACT) but reduced undecylprodigiosin (RED) and yellow type I polyketide (yCPK) production, suggesting that GluR-GluK plays a differential role in antibiotic biosynthesis. Furthermore, we found that the response regulator GluR directly promotes the expression of under the culture condition of MM with a high concentration of glutamate (75 mM). Using the biolayer interferometry assay, we demonstrated that glutamate acts as the direct signal of the histidine kinase GluK. It was therefore suggested that upon sensing high concentrations of glutamate, GluR-GluK would be activated and thereby facilitate glutamate uptake by increasing expression. Finally, we demonstrated that the role of GluR-GluK in antibiotic biosynthesis is independent of its function in glutamate uptake. Considering the wide distribution of the glutamate-sensing (GluR-GluK) and uptake (GluABCD) module in actinobacteria, it could be concluded that the GluR-GluK signal transduction pathway involved in secondary metabolism and glutamate uptake should be highly conserved in this bacterial phylum. In this study, a novel two-component system (TCS), GluR-GluK, was identified to be involved in glutamate sensing and uptake as well as antibiotic biosynthesis in A possible GluR-GluK working model was proposed. Upon sensing high glutamate concentrations (such as 75 mM), activated GluR-GluK could regulate both glutamate uptake and antibiotic biosynthesis. However, under a culture condition of MM supplemented with low concentrations of glutamate (such as 10 mM), although GluR-GluK is activated, its activity is sufficient only for the regulation of antibiotic biosynthesis. To the best of our knowledge, this is the first report describing a TCS signal transduction pathway for glutamate sensing and uptake in actinobacteria.
[Mh] Termos MeSH primário: Ácido Glutâmico/metabolismo
Histidina Quinase/metabolismo
Transdução de Sinais
Streptomyces coelicolor/metabolismo
Fatores de Transcrição/metabolismo
[Mh] Termos MeSH secundário: Transporte Biológico
Meios de Cultura/química
Deleção de Genes
Regulação da Expressão Gênica
Histidina Quinase/genética
Proteínas de Membrana Transportadoras/genética
Proteínas de Membrana Transportadoras/metabolismo
Óperon
Streptomyces coelicolor/genética
Fatores de Transcrição/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Culture Media); 0 (Membrane Transport Proteins); 0 (Transcription Factors); 3KX376GY7L (Glutamic Acid); EC 2.7.13.1 (Histidine Kinase)
[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


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[PMID]:29281637
[Au] Autor:Boot M; van Winden VJC; Sparrius M; van de Weerd R; Speer A; Ummels R; Rustad T; Sherman DR; Bitter W
[Ad] Endereço:Department of Medical Microbiology and Infection Control, VU University Medical Center, Amsterdam, the Netherlands.
[Ti] Título:Cell envelope stress in mycobacteria is regulated by the novel signal transduction ATPase IniR in response to trehalose.
[So] Source:PLoS Genet;13(12):e1007131, 2017 12.
[Is] ISSN:1553-7404
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The cell envelope of mycobacteria is a highly unique and complex structure that is functionally equivalent to that of Gram-negative bacteria to protect the bacterial cell. Defects in the integrity or assembly of this cell envelope must be sensed to allow the induction of stress response systems. The promoter that is specifically and most strongly induced upon exposure to ethambutol and isoniazid, first line drugs that affect cell envelope biogenesis, is the iniBAC promoter. In this study, we set out to identify the regulator of the iniBAC operon in Mycobacterium marinum using an unbiased transposon mutagenesis screen in a constitutively iniBAC-expressing mutant background. We obtained multiple mutants in the mce1 locus as well as mutants in an uncharacterized putative transcriptional regulator (MMAR_0612). This latter gene was shown to function as the iniBAC regulator, as overexpression resulted in constitutive iniBAC induction, whereas a knockout mutant was unable to respond to the presence of ethambutol and isoniazid. Experiments with the M. tuberculosis homologue (Rv0339c) showed identical results. RNAseq experiments showed that this regulatory gene was exclusively involved in the regulation of the iniBAC operon. We therefore propose to name this dedicated regulator iniBAC Regulator (IniR). IniR belongs to the family of signal transduction ATPases with numerous domains, including a putative sugar-binding domain. Upon testing different sugars, we identified trehalose as an activator and metabolic cue for iniBAC activation, which could also explain the effect of the mce1 mutations. In conclusion, cell envelope stress in mycobacteria is regulated by IniR in a cascade that includes trehalose.
[Mh] Termos MeSH primário: Adenosina Trifosfatases/genética
Mycobacterium marinum/genética
Mycobacterium marinum/metabolismo
Trealose/metabolismo
[Mh] Termos MeSH secundário: Proteínas de Bactérias/genética
Membrana Celular/metabolismo
Parede Celular/genética
Parede Celular/metabolismo
Elementos de DNA Transponíveis
Regulação Bacteriana da Expressão Gênica
Genes Bacterianos
Mutagênese Insercional
Óperon
Regiões Promotoras Genéticas
Transdução de Sinais
Transcrição Genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (DNA Transposable Elements); B8WCK70T7I (Trehalose); EC 3.6.1.- (Adenosine Triphosphatases)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180227
[Lr] Data última revisão:
180227
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171228
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pgen.1007131


  3 / 16038 MEDLINE  
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[PMID]:29358578
[Au] Autor:Bonneau M; Atyame C; Beji M; Justy F; Cohen-Gonsaud M; Sicard M; Weill M
[Ad] Endereço:Institut des Sciences de l'Evolution de Montpellier (ISEM), UMR CNRS-IRD-EPHE-Université de Montpellier, Place Eugène Bataillon, 34095, Montpellier, France.
[Ti] Título:Culex pipiens crossing type diversity is governed by an amplified and polymorphic operon of Wolbachia.
[So] Source:Nat Commun;9(1):319, 2018 01 22.
[Is] ISSN:2041-1723
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Culex pipiens mosquitoes are infected with Wolbachia (wPip) that cause an important diversity of cytoplasmic incompatibilities (CIs). Functional transgenic studies have implicated the cidA-cidB operon from wPip and its homolog in wMel in CI between infected Drosophila males and uninfected females. However, the genetic basis of the CI diversity induced by different Wolbachia strains was unknown. We show here that the remarkable diversity of CI in the C. pipiens complex is due to the presence, in all tested wPip genomes, of several copies of the cidA-cidB operon, which undergoes diversification through recombination events. In 183 isofemale lines of C. pipiens collected worldwide, specific variations of the cidA-cidB gene repertoires are found to match crossing types. The diversification of cidA-cidB is consistent with the hypothesis of a toxin-antitoxin system in which the gene cidB co-diversifies with the gene cidA, particularly in putative domains of reciprocal interactions.
[Mh] Termos MeSH primário: Proteínas de Bactérias/genética
Culex/microbiologia
Drosophila melanogaster/microbiologia
Genoma Bacteriano
Óperon
Wolbachia/genética
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Animais
Proteínas de Bactérias/metabolismo
Sequência de Bases
Cruzamentos Genéticos
Culex/genética
Drosophila melanogaster/genética
Feminino
Especificidade de Hospedeiro
Masculino
Polimorfismo Genético
Alinhamento de Sequência
Homologia de Sequência de Aminoácidos
Simbiose/genética
Sistemas Toxina-Antitoxina/genética
Wolbachia/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Proteins)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180222
[Lr] Data última revisão:
180222
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180124
[St] Status:MEDLINE
[do] DOI:10.1038/s41467-017-02749-w


  4 / 16038 MEDLINE  
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[PMID]:29293606
[Au] Autor:Ahmad Z; Harvey RM; Paton JC; Standish AJ; Morona R
[Ad] Endereço:Research Centre for Infectious Diseases, Department of Molecular & Cellular Biology, School of Biological Sciences, The University of Adelaide, South Australia, Australia.
[Ti] Título:Role of Streptococcus pneumoniae OM001 operon in capsular polysaccharide production, virulence and survival in human saliva.
[So] Source:PLoS One;13(1):e0190402, 2018.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Streptococcus pneumoniae is the leading cause of community-acquired pneumonia in all ages worldwide, and with ever-increasing antibiotic resistance, the understanding of its pathogenesis and spread is as important as ever. Recently, we reported the presence of a Low Molecular Weight Tyrosine Phosphatase (LMWPTP) Spd1837 in the pneumococcus. This protein is encoded in an operon, OM001 with two other genes, with previous work implicating this operon as important for pneumococcal virulence. Thus, we set out to investigate the role of the individual genes in the operon during pneumococcal pathogenesis. As LMWPTPs play a major role in capsular polysaccharide (CPS) biosynthesis in many bacteria, we tested the effect of mutating spd1837 and its adjacent genes, spd1836 and spd1838 on CPS levels. Our results suggest that individual deletion of the genes, including the LMWPTP, did not modulate CPS levels, in multiple conditions, and in different strain backgrounds. Following in vivo studies, Spd1836 was identified as a novel virulence factor during pneumococcal invasive disease, in both the lungs and blood, with this protein alone responsible for the effects of operon's role in virulence. We also showed that a deletion in spd1836, spd1838 or the overall OM001 operon reduced survival in human saliva during the conditions that mimic transmission compared to the wildtype strain. With studies suggesting that survival in human saliva may be important for transmission, this study identifies Spd1836 and Spd1838 as transmission factors, potentially facilitating the spread of the pneumococcus from person to person. Overall, this study hopes to further our understanding of the bacterial transmission that precedes disease and outbreaks.
[Mh] Termos MeSH primário: Óperon
Polissacarídeos/biossíntese
Saliva/microbiologia
Streptococcus pneumoniae/genética
Fatores de Virulência/metabolismo
[Mh] Termos MeSH secundário: Animais
Western Blotting
Eletroforese em Gel de Poliacrilamida
Feminino
Genes Bacterianos
Seres Humanos
Camundongos
Streptococcus pneumoniae/metabolismo
Streptococcus pneumoniae/patogenicidade
Virulência
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Polysaccharides); 0 (Virulence Factors)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180221
[Lr] Data última revisão:
180221
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180103
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0190402


  5 / 16038 MEDLINE  
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[PMID]:29372963
[Au] Autor:Melkina OE; Goryanin II; Zavilgelsky GB
[Ti] Título:[Histone-like protein H-NS as a negative regulator of quorum sensing systems in gram-negative bacteria].
[So] Source:Genetika;53(2):165-72, 2017 Feb.
[Is] ISSN:0016-6758
[Cp] País de publicação:Russia (Federation)
[La] Idioma:rus
[Ab] Resumo:The effects of histone-like protein H-NS on transcription of promoters of the Quorum Sensing regulated operons from marine luminescent mesophilic bacterium Aliivibrio fischeri and psychrophilic Aliivibrio logei, as well as from pathogenic Pseudomonas aeruginosa, are studied. In the present work, the plasmids carrying DNA fragments with the promoters Pr1f (upstream of the luxICDABEG operon from A. fischeri), Pr1l (upstream of the luxCDABEG operon from A. logei), Pr2l (upstream of luxI gene from A. logei), PluxCf (upstream of luxC gene from A. fischeri), and PlasI (upstream of lasI gene from P. aerugenosa) are used. In these plasmids, promoter-operator regions are transcriptionally fused to the reporter genes cassette luxCDABE from Photorhabdus luminescens. Here we have shown that the transcription of the QS-regulated promoters in E. coli hns::kan cells increases 100 to 1000 times. Furthermore, transcription of the QS-regulated promoters in E. coli hns + cells increases 10 to 100 times in the cells transformed with the plasmid carrying gene ardA ColIb-P9 encoding DNA mimic antirestriction protein ArdA, inhibitor of the type I restriction-modification systems.
[Mh] Termos MeSH primário: Aliivibrio fischeri
Proteínas de Bactérias
Proteínas de Ligação a DNA
Pseudomonas aeruginosa
Percepção de Quorum/fisiologia
[Mh] Termos MeSH secundário: Aliivibrio fischeri/genética
Aliivibrio fischeri/metabolismo
Proteínas de Bactérias/genética
Proteínas de Bactérias/metabolismo
Proteínas de Ligação a DNA/genética
Proteínas de Ligação a DNA/metabolismo
Escherichia coli/genética
Escherichia coli/metabolismo
Óperon/fisiologia
Regiões Promotoras Genéticas/fisiologia
Pseudomonas aeruginosa/genética
Pseudomonas aeruginosa/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (DNA-Binding Proteins); 0 (H-NS protein, bacteria)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180216
[Lr] Data última revisão:
180216
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180127
[St] Status:MEDLINE


  6 / 16038 MEDLINE  
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[PMID]:29293601
[Au] Autor:Kim Y; Jeon J; Kwak MS; Kim GH; Koh I; Rho M
[Ad] Endereço:Department of Computer Science and Engineering, Hanyang University, Seoul, Korea.
[Ti] Título:Photosynthetic functions of Synechococcus in the ocean microbiomes of diverse salinity and seasons.
[So] Source:PLoS One;13(1):e0190266, 2018.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Synechococcus is an important photosynthetic picoplankton in the temperate to tropical oceans. As a photosynthetic bacterium, Synechococcus has an efficient mechanism to adapt to the changes in salinity and light intensity. The analysis of the distributions and functions of such microorganisms in the ever changing river mouth environment, where freshwater and seawater mix, should help better understand their roles in the ecosystem. Toward this objective, we have collected and sequenced the ocean microbiome in the river mouth of Kwangyang Bay, Korea, as a function of salinity and temperature. In conjunction with comparative genomics approaches using the sequenced genomes of a wide phylogeny of Synechococcus, the ocean microbiome was analyzed in terms of their composition and clade-specific functions. The results showed significant differences in the compositions of Synechococcus sampled in different seasons. The photosynthetic functions in such enhanced Synechococcus strains were also observed in the microbiomes in summer, which is significantly different from those in other seasons.
[Mh] Termos MeSH primário: Microbiota
Oceanos e Mares
Fotossíntese
Salinidade
Estações do Ano
Synechococcus/fisiologia
Microbiologia da Água
[Mh] Termos MeSH secundário: Ecossistema
Genes Bacterianos
Óperon
Ficobilissomas/fisiologia
Filogenia
Synechococcus/classificação
Synechococcus/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Phycobilisomes)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180215
[Lr] Data última revisão:
180215
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180103
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0190266


  7 / 16038 MEDLINE  
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[PMID]:29240826
[Au] Autor:De San Eustaquio-Campillo A; Cornilleau C; Guérin C; Carballido-López R; Chastanet A
[Ad] Endereço:MICALIS, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France.
[Ti] Título:PamR, a new MarR-like regulator affecting prophages and metabolic genes expression in Bacillus subtilis.
[So] Source:PLoS One;12(12):e0189694, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:B. subtilis adapts to changing environments by reprogramming its genetic expression through a variety of transcriptional regulators from the global transition state regulators that allow a complete resetting of the cell genetic expression, to stress specific regulators controlling only a limited number of key genes required for optimal adaptation. Among them, MarR-type transcriptional regulators are known to respond to a variety of stresses including antibiotics or oxidative stress, and to control catabolic or virulence gene expression. Here we report the characterization of the ydcFGH operon of B. subtilis, containing a putative MarR-type transcriptional regulator. Using a combination of molecular genetics and high-throughput approaches, we show that this regulator, renamed PamR, controls directly its own expression and influence the expression of large sets of prophage-related and metabolic genes. The extent of the regulon impacted by PamR suggests that this regulator reprograms the metabolic landscape of B. subtilis in response to a yet unknown signal.
[Mh] Termos MeSH primário: Bacillus subtilis/genética
Proteínas de Bactérias/fisiologia
Regulação Bacteriana da Expressão Gênica/fisiologia
Prófagos/genética
[Mh] Termos MeSH secundário: Bacillus subtilis/metabolismo
Bacillus subtilis/virologia
Proteínas de Bactérias/genética
Carbono/metabolismo
Óperon
Regiões Promotoras Genéticas
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 7440-44-0 (Carbon)
[Em] Mês de entrada:1712
[Cu] Atualização por classe:171229
[Lr] Data última revisão:
171229
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171215
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0189694


  8 / 16038 MEDLINE  
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[PMID]:29206865
[Au] Autor:Dani P; Ujaoney AK; Apte SK; Basu B
[Ad] Endereço:Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai, India.
[Ti] Título:Regulation of potassium dependent ATPase (kdp) operon of Deinococcus radiodurans.
[So] Source:PLoS One;12(12):e0188998, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The genome of D. radiodurans harbors genes for structural and regulatory proteins of Kdp ATPase, in an operon pattern, on Mega plasmid 1. Organization of its two-component regulatory genes is unique. Here we demonstrate that both, the structural as well as regulatory components of the kdp operon of D. radiodurans are expressed quickly as the cells experience potassium limitation but are not expressed upon increase in osmolarity. The cognate DNA binding response regulator (RR) effects the expression of kdp operon during potassium deficiency through specific interaction with the kdp promoter. Deletion of the gene encoding RR protein renders the mutant D. radiodurans (ΔRR) unable to express kdp operon under potassium limitation. The ΔRR D. radiodurans displays no growth defect when grown on rich media or when exposed to oxidative or heat stress but shows reduced growth following gamma irradiation. The study elucidates the functional and regulatory aspects of the novel kdp operon of this extremophile, for the first time.
[Mh] Termos MeSH primário: Adenosina Trifosfatases/metabolismo
Deinococcus/genética
Óperon
Potássio/metabolismo
[Mh] Termos MeSH secundário: Adenosina Trifosfatases/genética
Deinococcus/crescimento & desenvolvimento
Ensaio de Desvio de Mobilidade Eletroforética
Genes Bacterianos
Pressão Osmótica
Estresse Fisiológico
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
EC 3.6.1.- (Adenosine Triphosphatases); RWP5GA015D (Potassium)
[Em] Mês de entrada:1712
[Cu] Atualização por classe:171229
[Lr] Data última revisão:
171229
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171206
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0188998


  9 / 16038 MEDLINE  
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[PMID]:28455338
[Au] Autor:Joyet P; Mokhtari A; Riboulet-Bisson E; Blancato VS; Espariz M; Magni C; Hartke A; Deutscher J; Sauvageot N
[Ad] Endereço:Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France.
[Ti] Título:Enzymes Required for Maltodextrin Catabolism in Enterococcus faecalis Exhibit Novel Activities.
[So] Source:Appl Environ Microbiol;83(13), 2017 Jul 01.
[Is] ISSN:1098-5336
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Maltose and maltodextrins are formed during the degradation of starch or glycogen. Maltodextrins are composed of a mixture of maltooligosaccharides formed by α-1,4- but also some α-1,6-linked glucosyl residues. The α-1,6-linked glucosyl residues are derived from branching points in the polysaccharides. In , maltotriose is mainly transported and phosphorylated by a phosphoenolpyruvate:carbohydrate phosphotransferase system. The formed maltotriose-6″-phosphate is intracellularly dephosphorylated by a specific phosphatase, MapP. In contrast, maltotetraose and longer maltooligosaccharides up to maltoheptaose are taken up without phosphorylation via the ATP binding cassette transporter MdxEFG-MsmX. We show that the maltose-producing maltodextrin hydrolase MmdH (GenBank accession no. EFT41964) in strain JH2-2 catalyzes the first catabolic step of α-1,4-linked maltooligosaccharides. The purified enzyme converts even-numbered α-1,4-linked maltooligosaccharides (maltotetraose, etc.) into maltose and odd-numbered (maltotriose, etc.) into maltose and glucose. Inactivation of therefore prevents the growth of on maltooligosaccharides ranging from maltotriose to maltoheptaose. Surprisingly, MmdH also functions as a maltogenic α-1,6-glucosidase, because it converts the maltotriose isomer isopanose into maltose and glucose. In addition, contains a glucose-producing α-1,6-specific maltodextrin hydrolase (GenBank accession no. EFT41963, renamed GmdH). This enzyme converts panose, another maltotriose isomer, into glucose and maltose. A mutant had therefore lost the capacity to grow on panose. The genes and are organized in an operon together with GenBank accession no. (renamed ). Purified MmgT transfers glucosyl residues from one α-1,4-linked maltooligosaccharide molecule to another. For example, it catalyzes the disproportionation of maltotriose by transferring a glucosyl residue to another maltotriose molecule, thereby forming maltotetraose and maltose together with a small amount of maltopentaose. The utilization of maltodextrins by has been shown to increase the virulence of this nosocomial pathogen. However, little is known about how this organism catabolizes maltodextrins. We identified two enzymes involved in the metabolism of various α-1,4- and α-1,6-linked maltooligosaccharides. We found that one of them functions as a maltose-producing α-glucosidase with relaxed linkage specificity (α-1,4 and α-1,6) and exo- and endoglucosidase activities. A third enzyme, which resembles amylomaltase, exclusively transfers glucosyl residues from one maltooligosaccharide molecule to another. Similar enzymes are present in numerous other , such as streptococci and lactobacilli, suggesting that these organisms follow the same maltose degradation pathway as .
[Mh] Termos MeSH primário: Proteínas de Bactérias/metabolismo
Enterococcus faecalis/enzimologia
Hidrolases/metabolismo
Polissacarídeos/biossíntese
[Mh] Termos MeSH secundário: Transportadores de Cassetes de Ligação de ATP/genética
Transportadores de Cassetes de Ligação de ATP/metabolismo
Proteínas de Bactérias/genética
Enterococcus faecalis/genética
Enterococcus faecalis/metabolismo
Hidrolases/genética
Maltose/metabolismo
Oligossacarídeos/metabolismo
Óperon
Trissacarídeos/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (ATP-Binding Cassette Transporters); 0 (Bacterial Proteins); 0 (Oligosaccharides); 0 (Polysaccharides); 0 (Trisaccharides); 0 (maltooligosaccharides); 639K0T34IK (maltotriose); 69-79-4 (Maltose); 7CVR7L4A2D (maltodextrin); EC 3.- (Hydrolases)
[Em] Mês de entrada:1712
[Cu] Atualização por classe:171225
[Lr] Data última revisão:
171225
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170430
[St] Status:MEDLINE


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[PMID]:28471356
[Au] Autor:Ha JH; Eo Y; Ahn HC; Ryu KS
[Ad] Endereço:Protein Structure Group, Korea Basic Science Institute, 162 Yeongudanji-ro, Ochang-eup, Cheongju-si, Chungcheongbuk-do 28119, Republic of Korea.
[Ti] Título:Increasing the soluble expression and crystallization of the Escherichia coli quorum-sensing protein LsrK.
[So] Source:Acta Crystallogr F Struct Biol Commun;73(Pt 5):253-258, 2017 May 01.
[Is] ISSN:2053-230X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:LsrK is one of the key components of the luxS-regulated (lsr) operon in Escherichia coli and plays an important role during the quorum-sensing (QS) process mediated by autoinducer-2 (AI-2). The AI-2 molecule is imported into the cell by the LsrACB transporter and is subsequently phosphorylated (to AI-2-P) by LsrK. AI-2-P binds to the repressor protein of the lsr operon (LsrR) and triggers various cellular responses related to QS by dissociating LsrR from the DNA. Although a large amount of purified LsrK is required for structural studies, recombinant GST-LsrK was mostly expressed in an insoluble form. To enhance the soluble expression of LsrK, an attempt was made to increase the expression of the cellular chaperone proteins that are well known to support proper protein folding. Transformed E. coli was cultured in high-salt LB medium and heat shock was applied prior to subsequent IPTG induction at 20°C. These procedures increased the yield of purified LsrK by about tenfold compared with standard IPTG induction at 20°C. The expressed LsrK was readily purified by GST-affinity chromatography. Crystals of LsrK were grown by the hanging-drop vapour-diffusion method. The X-ray diffraction data of the crystal were processed in a primitive hexagonal space group to 2.9 Šresolution.
[Mh] Termos MeSH primário: Cristalização/métodos
Proteínas de Escherichia coli/química
Escherichia coli/genética
Fosfotransferases (Aceptor do Grupo Álcool)/química
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Clonagem Molecular
Cristalografia por Raios X
Meios de Cultura/farmacologia
Escherichia coli/efeitos dos fármacos
Escherichia coli/metabolismo
Proteínas de Escherichia coli/genética
Proteínas de Escherichia coli/metabolismo
Expressão Gênica
Vetores Genéticos/química
Vetores Genéticos/metabolismo
Temperatura Alta
Isopropiltiogalactosídeo/farmacologia
Óperon
Fosfotransferases (Aceptor do Grupo Álcool)/genética
Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo
Percepção de Quorum/genética
Proteínas Recombinantes/química
Proteínas Recombinantes/genética
Proteínas Recombinantes/metabolismo
Solubilidade
Difração de Raios X
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Culture Media); 0 (Escherichia coli Proteins); 0 (Recombinant Proteins); 367-93-1 (Isopropyl Thiogalactoside); EC 2.7.1.- (LsrK protein, E coli); EC 2.7.1.- (Phosphotransferases (Alcohol Group Acceptor))
[Em] Mês de entrada:1712
[Cu] Atualização por classe:171204
[Lr] Data última revisão:
171204
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170505
[St] Status:MEDLINE
[do] DOI:10.1107/S2053230X1700468X



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