Base de dados : MEDLINE
Pesquisa : D08.811.682.655.500 [Categoria DeCS]
Referências encontradas : 1772 [refinar]
Mostrando: 1 .. 10   no formato [Detalhado]

página 1 de 178 ir para página                         

  1 / 1772 MEDLINE  
              next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28608300
[Au] Autor:Rajsz A; Wojtun B; Bytnerowicz A
[Ad] Endereço:Department of Ecology, Biogeochemistry and Environmental Protection, Wroclaw University, Kanonia 6/8, 50-328, Wroclaw, Poland. adam.rajsz@uwr.edu.pl.
[Ti] Título:In situ assay of nitrate reductase activity using portable water bath.
[So] Source:Environ Monit Assess;189(7):332, 2017 Jul.
[Is] ISSN:1573-2959
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:In environmental research (i.e., plant ecophysiology, environmental microbiology, and environmental chemistry), some assays require incubation of samples at controlled temperature and darkness. Until now, due to a lack of equipment providing such possibility in situ, researchers had to move collected samples to the laboratory for incubation. Obviously, a delayed incubation and the ex situ conditions could seriously affect the assays' results. A good example of analysis where water bath use is needed is the nitrate reductase activity (NRA) in vivo assay where plant tissue samples are incubated in buffer solution at a predetermined temperature. We designed a transportable water bath with a temperature control which enables in situ measurements in many types of environmental studies. The presented device is small in size featuring a thermally insulated chamber and an electronically controlled thermostat system powered by a 12-V battery. Due to its modular design, it can be transported comfortably in difficult terrain. The incubation process can be carried out continuously in stable temperature and darkness. In order to examine the field usability of the presented device, we conducted measurements of plant nitrate reductase activity in difficult field conditions. The in situ assays were carried out at high altitudes in the Karkonosze mountains, SW Poland. The NRA was studied in two alpine species (Deschampsia caespitosa and Homogyne alpina). Our results showed low NR activity in H. alpina (mean 0.31 µM NO g DW h ) and higher NRA in D. caespitosa (mean 2.7 µM NO g DW h ). The obtained results were highly reproducible and had small variability (low standard error values).
[Mh] Termos MeSH primário: Bioensaio/instrumentação
Monitoramento Ambiental/instrumentação
Nitrato Redutase/análise
[Mh] Termos MeSH secundário: Banhos
Escuridão
Nitrato Redutase/metabolismo
Nitrato Redutases
Nitratos
Oxirredução
Raízes de Plantas/metabolismo
Poaceae/metabolismo
Polônia
Água
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Nitrates); 059QF0KO0R (Water); EC 1.7.- (Nitrate Reductases); EC 1.7.99.4 (Nitrate Reductase)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170718
[Lr] Data última revisão:
170718
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170614
[St] Status:MEDLINE
[do] DOI:10.1007/s10661-017-6045-9


  2 / 1772 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28388834
[Au] Autor:Haase D; Hermann B; Einsle O; Simon J
[Ad] Endereço:Microbial Energy Conversion and Biotechnology, Department of Biology, Technische Universität Darmstadt, Schnittspahnstraße 10, 64287, Darmstadt, Germany.
[Ti] Título:Epsilonproteobacterial hydroxylamine oxidoreductase (εHao): characterization of a 'missing link' in the multihaem cytochrome c family.
[So] Source:Mol Microbiol;105(1):127-138, 2017 07.
[Is] ISSN:1365-2958
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Members of the multihaem cytochrome c family such as pentahaem cytochrome c nitrite reductase (NrfA) or octahaem hydroxylamine oxidoreductase (Hao) are involved in various microbial respiratory electron transport chains. Some members of the Hao subfamily, here called εHao proteins, have been predicted from the genomes of nitrate/nitrite-ammonifying bacteria that usually lack NrfA. Here, εHao proteins from the host-associated Epsilonproteobacteria Campylobacter fetus and Campylobacter curvus and the deep-sea hydrothermal vent bacteria Caminibacter mediatlanticus and Nautilia profundicola were purified as εHao-maltose binding protein fusions produced in Wolinella succinogenes. All four proteins were able to catalyze reduction of nitrite (yielding ammonium) and hydroxylamine whereas hydroxylamine oxidation was negligible. The introduction of a tyrosine residue at a position known to cause covalent trimerization of Hao proteins did neither stimulate hydroxylamine oxidation nor generate the Hao-typical absorbance maximum at 460 nm. In most cases, the εHao-encoding gene haoA was situated downstream of haoC, which predicts a tetrahaem cytochrome c of the NapC/NrfH family. This suggested the formation of a membrane-bound HaoCA assembly reminiscent of the menaquinol-oxidizing NrfHA complex. The results indicate that εHao proteins form a subfamily of ammonifying cytochrome c nitrite reductases that represents a 'missing link' in the evolution of NrfA and Hao enzymes.
[Mh] Termos MeSH primário: Citocromos c/metabolismo
Oxirredutases/metabolismo
[Mh] Termos MeSH secundário: Proteínas de Bactérias/metabolismo
Grupo dos Citocromos c
Citocromos a1/metabolismo
Citocromos c1/metabolismo
Epsilonproteobacteria/genética
Epsilonproteobacteria/metabolismo
Nitrato Redutases/metabolismo
Nitritos/metabolismo
Oxirredução
Oxirredutases/genética
Wolinella/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Cytochrome c Group); 0 (Nitrites); 9007-43-6 (Cytochromes c); 9035-35-2 (Cytochromes a1); 9035-42-1 (Cytochromes c1); 9048-78-6 (cytochrome C-552); EC 1.- (Oxidoreductases); EC 1.7.- (Nitrate Reductases); EC 1.7.2.6 (hydroxylamine dehydrogenase); EC 1.9.6.1 (nitrate reductase (cytochrome))
[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:170408
[St] Status:MEDLINE
[do] DOI:10.1111/mmi.13690


  3 / 1772 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27924403
[Au] Autor:Gao M; Liu J; Qiao Y; Zhao M; Zhang XH
[Ad] Endereço:College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao, 266003, China.
[Ti] Título:Diversity and Abundance of the Denitrifying Microbiota in the Sediment of Eastern China Marginal Seas and the Impact of Environmental Factors.
[So] Source:Microb Ecol;73(3):602-615, 2017 Apr.
[Is] ISSN:1432-184X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Investigating the environmental influence on the community composition and abundance of denitrifiers in marine sediment ecosystem is essential for understanding of the ecosystem-level controls on the biogeochemical process of denitrification. In the present study, nirK-harboring denitrifying communities in different mud deposit zones of eastern China marginal seas (ECMS) were investigated via clone library analysis. The abundance of three functional genes affiliated with denitrification (narG, nirK, nosZ) was assessed by fluorescent quantitative PCR. The nirK-harboring microbiota were dominated by a few operational taxonomic units (OTUs), which were widely distributed in different sites with each site harboring their unique phylotypes. The mean abundance of nirK was significantly higher than that of narG and nosZ genes, and the abundance of narG was higher than that of nosZ. The inconsistent abundance profile of different functional genes along the process of denitrification might indicate that nitrite reduction occurred independently of denitrification in the mud deposit zones of ECMS, and sedimentary denitrification was accomplished by cooperation of different denitrifying species rather than a single species. Such important information would be missed when targeting only a single denitrifying functional gene. Analysis of correlation between abundance ratios and environmental factors revealed that the response of denitrifiers to environmental factors was not invariable in different mud deposit zones. Our results suggested that a comprehensive analysis of different denitrifying functional genes may gain more information about the dynamics of denitrifying microbiota in marine sediments.
[Mh] Termos MeSH primário: Bactérias/metabolismo
Desnitrificação/genética
Sedimentos Geológicos/microbiologia
Microbiota/genética
Nitrato Redutases/genética
Nitrito Redutases/genética
Ciclo do Nitrogênio/genética
[Mh] Termos MeSH secundário: Bactérias/genética
Biodiversidade
China
Nitratos/metabolismo
Nitritos/metabolismo
Ciclo do Nitrogênio/fisiologia
Oceanos e Mares
Oxirredutases/genética
Filogenia
Microbiologia do Solo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Nitrates); 0 (Nitrites); EC 1.- (Oxidoreductases); EC 1.7.- (Nitrate Reductases); EC 1.7.- (Nitrite Reductases); EC 1.7.2.4 (nitrous oxide reductase); EC 1.7.2.5 (nitric-oxide reductase)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170922
[Lr] Data última revisão:
170922
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161208
[St] Status:MEDLINE
[do] DOI:10.1007/s00248-016-0906-6


  4 / 1772 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
[PMID]:27846604
[Au] Autor:Ford CL; Park YJ; Matson EM; Gordon Z; Fout AR
[Ad] Endereço:School of Chemical Sciences, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, IL 61801, USA.
[Ti] Título:A bioinspired iron catalyst for nitrate and perchlorate reduction.
[So] Source:Science;354(6313):741-743, 2016 11 11.
[Is] ISSN:1095-9203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Nitrate and perchlorate have considerable use in technology, synthetic materials, and agriculture; as a result, they have become pervasive water pollutants. Industrial strategies to chemically reduce these oxyanions often require the use of harsh conditions, but microorganisms can efficiently reduce them enzymatically. We developed an iron catalyst inspired by the active sites of nitrate reductase and (per)chlorate reductase enzymes. The catalyst features a secondary coordination sphere that aids in oxyanion deoxygenation. Upon reduction of the oxyanions, an iron(III)-oxo is formed, which in the presence of protons and electrons regenerates the catalyst and releases water.
[Mh] Termos MeSH primário: Biocatálise
Ferro/química
Nitrato Redutases/química
Nitratos/química
Oxirredutases/química
Percloratos/química
[Mh] Termos MeSH secundário: Domínio Catalítico
Oxirredução
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Nitrates); 0 (Perchlorates); E1UOL152H7 (Iron); EC 1.- (Oxidoreductases); EC 1.7.- (Nitrate Reductases); EC 1.97.1.1 (chlorate reductase); VLA4NZX2P4 (perchlorate)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170626
[Lr] Data última revisão:
170626
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161116
[St] Status:MEDLINE


  5 / 1772 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
[PMID]:27742892
[Au] Autor:Hansen MN; Lundberg JO; Filice M; Fago A; Christensen NM; Jensen FB
[Ad] Endereço:Department of Biology, University of Southern Denmark, Odense M DK-5230, Denmark.
[Ti] Título:The roles of tissue nitrate reductase activity and myoglobin in securing nitric oxide availability in deeply hypoxic crucian carp.
[So] Source:J Exp Biol;219(Pt 24):3875-3883, 2016 Dec 15.
[Is] ISSN:1477-9145
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:In mammals, treatment with low doses of nitrite has a cytoprotective effect in ischemia/reperfusion events, as a result of nitric oxide formation and S-nitrosation of proteins. Interestingly, anoxia-tolerant lower vertebrates possess an intrinsic ability to increase intracellular nitrite concentration during anoxia in tissues with high myoglobin and mitochondria content, such as the heart. Here, we tested the hypothesis that red and white skeletal muscles develop different nitrite levels in crucian carp exposed to deep hypoxia and assessed whether this correlates with myoglobin concentration. We also tested whether liver, muscle and heart tissue possess nitrate reductase activity that supplies nitrite to the tissues during severe hypoxia. Crucian carp exposed to deep hypoxia (1

[Mh] Termos MeSH primário: Carpas/metabolismo
Hipóxia/metabolismo
Mioglobina/metabolismo
Nitrato Redutases/metabolismo
Óxido Nítrico/metabolismo
Especificidade de Órgãos
[Mh] Termos MeSH secundário: Alopurinol/farmacologia
Animais
Carpas/sangue
Feminino
Fígado/efeitos dos fármacos
Fígado/enzimologia
Masculino
Metaboloma/efeitos dos fármacos
Músculos/efeitos dos fármacos
Músculos/enzimologia
Miocárdio/enzimologia
Óxido Nítrico/sangue
Nitritos/metabolismo
Especificidade de Órgãos/efeitos dos fármacos
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Myoglobin); 0 (Nitrites); 31C4KY9ESH (Nitric Oxide); 63CZ7GJN5I (Allopurinol); EC 1.7.- (Nitrate Reductases)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170818
[Lr] Data última revisão:
170818
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161016
[St] Status:MEDLINE


  6 / 1772 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27586496
[Au] Autor:Parey K; Fielding AJ; Sörgel M; Rachel R; Huber H; Ziegler C; Rajendran C
[Ad] Endereço:Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany. kristian.parey@biophys.mpg.de.
[Ti] Título:In meso crystal structure of a novel membrane-associated octaheme cytochrome c from the Crenarchaeon Ignicoccus hospitalis.
[So] Source:FEBS J;283(20):3807-3820, 2016 Oct.
[Is] ISSN:1742-4658
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The Crenarchaeon Ignicoccus hospitalis lives in symbiosis with Nanoarchaeum equitans providing essential cell components and nutrients to its symbiont. Ignicoccus hospitalis shows an intriguing morphology that points toward an evolutionary role in driving compartmentalization. Therefore, the bioenergetics of this archaeal host-symbiont system remains a pressing question. To date, the only electron acceptor described for I. hospitalis is elemental sulfur, but the organism comprises genes that encode for enzymes involved in nitrogen metabolism, e.g., one nitrate reductase and two octaheme cytochrome c, Igni_0955 (IhOCC) and Igni_1359. Herein, we detail functional and structural studies of the highly abundant IhOCC, including an X-ray crystal structure at 1.7 Å resolution, the first three-dimensional structure of an archaeal OCC. The trimeric IhOCC is membrane associated and exhibits significant structural and functional differences to previously characterized homologs within the hydroxylamine oxidoreductases (HAOs) and octaheme cytochrome c nitrite reductases (ONRs). The positions and spatial arrangement of the eight hemes are highly conserved, but the axial ligands of the individual hemes 3, 6 and 7 and the protein environment of the active site show significant differences. Most notably, the active site heme 4 lacks porphyrin-tyrosine cross-links present in the HAO family. We show that IhOCC efficiently reduces nitrite and hydroxylamine, with possible relevance to detoxification or energy conservation. DATABASE: Structural data are available in the Protein Data Bank under the accession number 4QO5.
[Mh] Termos MeSH primário: Proteínas Arqueais/química
Citocromos c/química
Desulfurococcaceae/química
[Mh] Termos MeSH secundário: Proteínas Arqueais/genética
Proteínas Arqueais/metabolismo
Sítios de Ligação
Sequência Conservada
Cristalografia por Raios X
Citocromos a1/química
Citocromos a1/genética
Citocromos a1/metabolismo
Citocromos c/genética
Citocromos c/metabolismo
Citocromos c1/química
Citocromos c1/genética
Citocromos c1/metabolismo
Desulfurococcaceae/genética
Desulfurococcaceae/metabolismo
Evolução Molecular
Genes Arqueais
Heme/química
Modelos Moleculares
Nitrato Redutases/química
Nitrato Redutases/genética
Nitrato Redutases/metabolismo
Estrutura Quaternária de Proteína
Subunidades Proteicas
Eletricidade Estática
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Archaeal Proteins); 0 (Protein Subunits); 42VZT0U6YR (Heme); 9007-43-6 (Cytochromes c); 9035-35-2 (Cytochromes a1); 9035-42-1 (Cytochromes c1); EC 1.7.- (Nitrate Reductases); EC 1.9.6.1 (nitrate reductase (cytochrome))
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170620
[Lr] Data última revisão:
170620
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160903
[St] Status:MEDLINE
[do] DOI:10.1111/febs.13870


  7 / 1772 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
[PMID]:27487207
[Au] Autor:Tsementzi D; Wu J; Deutsch S; Nath S; Rodriguez-R LM; Burns AS; Ranjan P; Sarode N; Malmstrom RR; Padilla CC; Stone BK; Bristow LA; Larsen M; Glass JB; Thamdrup B; Woyke T; Konstantinidis KT; Stewart FJ
[Ti] Título:SAR11 bacteria linked to ocean anoxia and nitrogen loss.
[So] Source:Nature;536(7615):179-83, 2016 08 11.
[Is] ISSN:1476-4687
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Bacteria of the SAR11 clade constitute up to one half of all microbial cells in the oxygen-rich surface ocean. SAR11 bacteria are also abundant in oxygen minimum zones (OMZs), where oxygen falls below detection and anaerobic microbes have vital roles in converting bioavailable nitrogen to N2 gas. Anaerobic metabolism has not yet been observed in SAR11, and it remains unknown how these bacteria contribute to OMZ biogeochemical cycling. Here, genomic analysis of single cells from the world's largest OMZ revealed previously uncharacterized SAR11 lineages with adaptations for life without oxygen, including genes for respiratory nitrate reductases (Nar). SAR11 nar genes were experimentally verified to encode proteins catalysing the nitrite-producing first step of denitrification and constituted ~40% of OMZ nar transcripts, with transcription peaking in the anoxic zone of maximum nitrate reduction activity. These results link SAR11 to pathways of ocean nitrogen loss, redefining the ecological niche of Earth's most abundant organismal group.
[Mh] Termos MeSH primário: Alphaproteobacteria/classificação
Alphaproteobacteria/metabolismo
Organismos Aquáticos/metabolismo
Nitrogênio/análise
Oceanos e Mares
Oxigênio/análise
Água do Mar/química
[Mh] Termos MeSH secundário: Adaptação Fisiológica/genética
Alphaproteobacteria/genética
Alphaproteobacteria/isolamento & purificação
Anaerobiose/genética
Organismos Aquáticos/enzimologia
Organismos Aquáticos/genética
Organismos Aquáticos/isolamento & purificação
Desnitrificação
Perfilação da Expressão Gênica
Genes Bacterianos
Genoma Bacteriano/genética
Nitrato Redutases/genética
Nitrato Redutases/metabolismo
Nitratos/metabolismo
Nitritos/metabolismo
Nitrogênio/metabolismo
Oxirredução
Oxigênio/metabolismo
Filogenia
Análise de Célula Única
Transcrição Genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Nitrates); 0 (Nitrites); EC 1.7.- (Nitrate Reductases); N762921K75 (Nitrogen); S88TT14065 (Oxygen)
[Em] Mês de entrada:1609
[Cu] Atualização por classe:170922
[Lr] Data última revisão:
170922
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160804
[St] Status:MEDLINE


  8 / 1772 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27256897
[Au] Autor:Khodashenas B; Ghorbani HR
[Ad] Endereço:Department of Chemical Engineering, Shahrood Branch, Islamic Azad University, Shahrood, Iran. bahar.khodashenas67@gmail.com.
[Ti] Título:Optimisation of nitrate reductase enzyme activity to synthesise silver nanoparticles.
[So] Source:IET Nanobiotechnol;10(3):158-61, 2016 Jun.
[Is] ISSN:1751-8741
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Today, the synthesis of silver nanoparticles (Ag NPs) is very common since it has many applications in different areas. The synthesis of these nanoparticles is done by means of physical, chemical, or biological methods. However, due to its inexpensive and environmentally friendly features, the biological method is more preferable. In the present study, using nitrate reductase enzyme available in the Escherichia coli (E. coli) bacterium, the biosynthesis of Ag NPs was investigated. In addition, the activity of the nitrate reductase enzyme was optimised by changing its cultural conditions, and the effects of silver nitrate (AgNO(3)) concentration and enzyme amount on nanoparticles synthesis were studied. Finally, the produced nanoparticles were studied using ultraviolet -visible (UV-Vis) spectrophotometer, dynamic light scattering technique, and transmission electron microscopy. UV-Visible spectrophotometric study showed the characteristic peak for Ag NPs at wavelength 405-420 nm for 1 mM metal precursor solution (AgNO(3)) with 1, 5, 10, and 20 cc supernatant and 435 nm for 0.01M AgNO(3) with 20 cc supernatant. In this study, it was found that there is a direct relationship between the AgNO(3) concentration and the size of produced Ag NPs.
[Mh] Termos MeSH primário: Proteínas de Escherichia coli/metabolismo
Nanopartículas Metálicas/química
Nitrato Redutases/metabolismo
Prata/metabolismo
[Mh] Termos MeSH secundário: Reatores Biológicos/microbiologia
Difusão Dinâmica da Luz
Escherichia coli/enzimologia
Escherichia coli/metabolismo
Proteínas de Escherichia coli/química
Microscopia Eletrônica de Transmissão
Nitrato Redutases/química
Tamanho da Partícula
Prata/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Escherichia coli Proteins); 3M4G523W1G (Silver); EC 1.7.- (Nitrate Reductases)
[Em] Mês de entrada:1609
[Cu] Atualização por classe:161021
[Lr] Data última revisão:
161021
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160604
[St] Status:MEDLINE
[do] DOI:10.1049/iet-nbt.2015.0062


  9 / 1772 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27010745
[Au] Autor:Wei H; Dai J; Xia M; Romine MF; Shi L; Beliav A; Tiedje JM; Nealson KH; Fredrickson JK; Zhou J; Qiu D
[Ad] Endereço:1​ Institute of hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China 2​ University of Chinese Academy of Sciences, Beijing 100049, PR China.
[Ti] Título:Functional roles of CymA and NapC in reduction of nitrate and nitrite by Shewanella putrefaciens W3-18-1.
[So] Source:Microbiology;162(6):930-41, 2016 Jun.
[Is] ISSN:1465-2080
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Shewanella putrefaciens W3-18-1 harbours two periplasmic nitrate reductase (Nap) gene clusters, NapC-associated nap-alpha (napEDABC) and CymA-dependent nap-beta (napDAGHB), for dissimilatory nitrate respiration. CymA is a member of the NapC/NirT quinol dehydrogenase family and acts as a hub to support different respiratory pathways, including those on iron [Fe(III)] and manganese [Mn(III, IV)] (hydr)oxide, nitrate, nitrite, fumarate and arsenate in Shewanella strains. However, in our analysis it was shown that another NapC/NirT family protein, NapC, was only involved in nitrate reduction, although both CymA and NapC can transfer quinol-derived electrons to a periplasmic terminal reductase or an electron acceptor. Furthermore, our results showed that NapC could only interact specifically with the Nap-alpha nitrate reductase while CymA could interact promiscuously with Nap-alpha, Nap-beta and the NrfA nitrite reductase for nitrate and nitrite reduction. To further explore the difference in specificity, site-directed mutagenesis on both CymA and NapC was conducted and the phenotypic changes in nitrate and nitrite reduction were tested. Our analyses demonstrated that the Lys-91 residue played a key role in nitrate reduction for quinol oxidation and the Asp-166 residue might influence the maturation of CymA. The Asp-97 residue might be one of the key factors that influence the interaction of CymA with the cytochromes NapB and NrfA.
[Mh] Termos MeSH primário: Nitrato Redutases/genética
Nitratos/metabolismo
Nitritos/metabolismo
Shewanella putrefaciens/metabolismo
[Mh] Termos MeSH secundário: Sequência de Aminoácidos/genética
Ácido Aspártico/metabolismo
Grupo dos Citocromos c/metabolismo
Hidroquinonas/metabolismo
Lisina/metabolismo
Mutagênese Sítio-Dirigida
Oxirredução
Alinhamento de Sequência
Shewanella putrefaciens/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Cytochrome c Group); 0 (Hydroquinones); 0 (Nitrates); 0 (Nitrites); 30KYC7MIAI (Aspartic Acid); EC 1.7.- (Nitrate Reductases); K3Z4F929H6 (Lysine)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171004
[Lr] Data última revisão:
171004
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160325
[St] Status:MEDLINE
[do] DOI:10.1099/mic.0.000285


  10 / 1772 MEDLINE  
              first record previous record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:26426528
[Au] Autor:Vázquez-Torres A; Bäumler AJ
[Ad] Endereço:Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO, United States; Veterans Affairs Eastern Colorado Health Care System, Denver, CO, United States. Electronic address: andres.vazquez-torres@ucdenver.edu.
[Ti] Título:Nitrate, nitrite and nitric oxide reductases: from the last universal common ancestor to modern bacterial pathogens.
[So] Source:Curr Opin Microbiol;29:1-8, 2016 Feb.
[Is] ISSN:1879-0364
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The electrochemical gradient that ensues from the enzymatic activity of cytochromes such as nitrate reductase, nitric oxide reductase, and quinol oxidase contributes to the bioenergetics of the bacterial cell. Reduction of nitrogen oxides by bacterial pathogens can, however, be uncoupled from proton translocation and biosynthesis of ATP or NH4(+), but still linked to quinol and NADH oxidation. Ancestral nitric oxide reductases, as well as cytochrome c oxidases and quinol bo oxidases evolved from the former, are capable of binding and detoxifying nitric oxide to nitrous oxide. The NO-metabolizing activity associated with these cytochromes can be a sizable source of antinitrosative defense in bacteria during their associations with host cells. Nitrosylation of terminal cytochromes arrests respiration, reprograms bacterial metabolism, stimulates antioxidant defenses and alters antibiotic cytotoxicity. Collectively, the bioenergetics and regulation of redox homeostasis that accompanies the utilization of nitrogen oxides and detoxification of nitric oxide by cytochromes of the electron transport chain increases fitness of many Gram-positive and -negative pathogens during their associations with invertebrate and vertebrate hosts.
[Mh] Termos MeSH primário: Bactérias/metabolismo
Bactérias/patogenicidade
Citocromos/metabolismo
Nitrato Redutases/metabolismo
Oxirredutases/metabolismo
[Mh] Termos MeSH secundário: Anaerobiose
Farmacorresistência Bacteriana
Transporte de Elétrons
Metabolismo Energético
Homeostase
Óxido Nítrico/metabolismo
Nitritos/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.; REVIEW
[Nm] Nome de substância:
0 (Cytochromes); 0 (Nitrites); 31C4KY9ESH (Nitric Oxide); EC 1.- (Oxidoreductases); EC 1.7.- (Nitrate Reductases); EC 1.7.2.5 (nitric-oxide reductase)
[Em] Mês de entrada:1611
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:151002
[St] Status:MEDLINE



página 1 de 178 ir para página                         
   


Refinar a pesquisa
  Base de dados : MEDLINE Formulário avançado   

    Pesquisar no campo  
1  
2
3
 
           



Search engine: iAH v2.6 powered by WWWISIS

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