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Pesquisa : B03.440.400.425.115.030.100 [Categoria DeCS]
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  1 / 17 MEDLINE  
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[PMID]:24813397
[Au] Autor:Gast P; Broeren FG; Sottini S; Aoki R; Takashina A; Yamaguchi T; Kohzuma T; Groenen EJ
[Ad] Endereço:Leiden University, Department of Physics, Huygens-Kamerlingh Onnes Laboratory, P.O. Box 9504, NL-2300 RA Leiden, The Netherlands. Electronic address: gast@physics.leidenuniv.nl.
[Ti] Título:The type 1 copper site of pseudoazurin: axial and rhombic.
[So] Source:J Inorg Biochem;137:57-63, 2014 Aug.
[Is] ISSN:1873-3344
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:We report on a high-frequency electron-paramagnetic-resonance study of the type 1 copper site of pseudoazurin. The spectra fully resolve the contribution of a nearly axial spectrum besides the rhombic spectrum, which unequivocally proves the existence of two conformations of the copper site. Pseudoazurins have been considered from Achromobacter cycloclastes including eight mutants and from Alcaligenes faecalis. The two conformations are virtually the same for all pseudoazurins, but the rhombic/axial population varies largely, between 91/9 and 33/67. These observations are discussed in relation to optical absorption spectra and X-ray diffraction structures. A similar observation for fern plastocyanin from Dryopteris crassirhizoma suggests that dual conformations of type 1 copper sites are more common.
[Mh] Termos MeSH primário: Azurina/química
Cobre/química
Plastocianina/química
Conformação Proteica
[Mh] Termos MeSH secundário: Achromobacter cycloclastes/química
Alcaligenes faecalis/química
Azurina/metabolismo
Sítios de Ligação
Espectroscopia de Ressonância de Spin Eletrônica
Plastocianina/metabolismo
Análise Espectral Raman
Difração de Raios X
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (pseudoazurin); 12284-43-4 (Azurin); 789U1901C5 (Copper); 9014-09-9 (Plastocyanin)
[Em] Mês de entrada:1502
[Cu] Atualização por classe:140609
[Lr] Data última revisão:
140609
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:140513
[St] Status:MEDLINE


  2 / 17 MEDLINE  
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[PMID]:22910335
[Au] Autor:Fujita K; Hirasawa-Fujita M; Brown DE; Obara Y; Ijima F; Kohzuma T; Dooley DM
[Ad] Endereço:Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA. fujitak@med.umich.edu
[Ti] Título:Direct electron transfer from pseudoazurin to nitrous oxide reductase in catalytic N2O reduction.
[So] Source:J Inorg Biochem;115:163-73, 2012 Oct.
[Is] ISSN:1873-3344
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Pseudoazurin (PAz), a well-characterized blue copper electron-transfer protein, is shown herein to be capable of mediating electron transfer to the nitrous oxide reductase (N(2)OR) from Achromobacter cycloclastes (Ac). Spectroscopic measurements demonstrate that reduced PAz is efficiently re-oxidized by a catalytic amount of N(2)OR in the presence of N(2)O. Fits of the kinetics resulted in K(M) (N(2)O) and k(cat) values of 19.1±3.8 µM and 89.3±4.2s(-1) respectively. The K(M) (PAz) was 28.8±6.6 µM. The electrochemistry of Ac pseudoazurin (AcPAz) in the presence of Ac nitrous oxide reductase (AcN(2)OR) and N(2)O displayed an enhanced cathodic sigmoidal current-potential curve, in excellent agreement with the re-oxidation of reduced AcPAz during the catalytic reduction of N(2)O by AcN(2)OR. Modeling the structure of the AcPAz-AcN(2)OR electron transfer complex indicates that AcPAz binds near Cu(A) in AcN(2)OR, with parameters consistent with the formation of a transient, weakly-bound complex. Multiple, potentially efficient electron-transfer pathways between the blue-copper center in AcPAz and Cu(A) were also identified. Collectively, the data establish that PAz is capable of donating electrons to N(2)OR in N(2)O reduction and is a strong candidate for the physiological electron donor to N(2)OR in Ac.
[Mh] Termos MeSH primário: Achromobacter cycloclastes/química
Azurina/química
Proteínas de Bactérias/química
Óxido Nitroso/química
Oxirredutases/química
[Mh] Termos MeSH secundário: Transporte de Elétrons
Cinética
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 (Bacterial Proteins); 0 (pseudoazurin); 12284-43-4 (Azurin); EC 1.- (Oxidoreductases); EC 1.7.2.4 (nitrous oxide reductase); K50XQU1029 (Nitrous Oxide)
[Em] Mês de entrada:1302
[Cu] Atualização por classe:131121
[Lr] Data última revisão:
131121
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:120823
[St] Status:MEDLINE


  3 / 17 MEDLINE  
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[PMID]:21739254
[Au] Autor:Dell'acqua S; Moura I; Moura JJ; Pauleta SR
[Ad] Endereço:REQUIMTE/CQFB, Departamento de Química, Universidade Nova de Lisboa, Caparica, Portugal.
[Ti] Título:The electron transfer complex between nitrous oxide reductase and its electron donors.
[So] Source:J Biol Inorg Chem;16(8):1241-54, 2011 Dec.
[Is] ISSN:1432-1327
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:Identifying redox partners and the interaction surfaces is crucial for fully understanding electron flow in a respiratory chain. In this study, we focused on the interaction of nitrous oxide reductase (N(2)OR), which catalyzes the final step in bacterial denitrification, with its physiological electron donor, either a c-type cytochrome or a type 1 copper protein. The comparison between the interaction of N(2)OR from three different microorganisms, Pseudomonas nautica, Paracoccus denitrificans, and Achromobacter cycloclastes, with their physiological electron donors was performed through the analysis of the primary sequence alignment, electrostatic surface, and molecular docking simulations, using the bimolecular complex generation with global evaluation and ranking algorithm. The docking results were analyzed taking into account the experimental data, since the interaction is suggested to have either a hydrophobic nature, in the case of P. nautica N(2)OR, or an electrostatic nature, in the case of P. denitrificans N(2)OR and A. cycloclastes N(2)OR. A set of well-conserved residues on the N(2)OR surface were identified as being part of the electron transfer pathway from the redox partner to N(2)OR (Ala495, Asp519, Val524, His566 and Leu568 numbered according to the P. nautica N(2)OR sequence). Moreover, we built a model for Wolinella succinogenes N(2)OR, an enzyme that has an additional c-type-heme-containing domain. The structures of the N(2)OR domain and the c-type-heme-containing domain were modeled and the full-length structure was obtained by molecular docking simulation of these two domains. The orientation of the c-type-heme-containing domain relative to the N(2)OR domain is similar to that found in the other electron transfer complexes.
[Mh] Termos MeSH primário: Cobre/química
Grupo dos Citocromos c/química
Modelos Moleculares
Oxirredutases/química
Oxirredutases/genética
[Mh] Termos MeSH secundário: Achromobacter cycloclastes/enzimologia
Simulação por Computador
Transporte de Elétrons
Metaloproteínas/química
Oxirredução
Paracoccus denitrificans/enzimologia
Conformação Proteica
Alinhamento de Sequência
Wolinella/enzimologia
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Cytochrome c Group); 0 (Metalloproteins); 789U1901C5 (Copper); EC 1.- (Oxidoreductases); EC 1.7.2.4 (nitrous oxide reductase)
[Em] Mês de entrada:1203
[Cu] Atualização por classe:171013
[Lr] Data última revisão:
171013
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:110709
[St] Status:MEDLINE
[do] DOI:10.1007/s00775-011-0812-9


  4 / 17 MEDLINE  
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[PMID]:20007000
[Au] Autor:Fitzpatrick MB; Obara Y; Fujita K; Brown DE; Dooley DM; Kohzuma T; Czernuszewicz RS
[Ad] Endereço:Department of Chemistry, University of Houston, Houston, TX 77204-5003, USA.
[Ti] Título:Non-covalent interactions in blue copper protein probed by Met16 mutation and electronic and resonance Raman spectroscopy of Achromobacter cycloclastes pseudoazurin.
[So] Source:J Inorg Biochem;104(3):250-60, 2010 Mar.
[Is] ISSN:1873-3344
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:We have used low-temperature (77K) resonance Raman (RR) spectroscopy as a probe of the electronic and molecular structure to investigate weak pi-pi interactions between the metal ion-coordinated His imidazoles and aromatic side chains in the second coordination sphere of blue copper proteins. For this purpose, the RR spectra of Met16 mutants of Achromobacter cycloclastes pseudoazurin (AcPAz) with aromatic (Met16Tyr, Met16Trp, and Met16Phe) and aliphatic (Met16Ala, Met16Val, Met16Leu, and Met16Ile) amino acid side chains have been obtained and analyzed over the 100-500cm(-1) spectral region. Subtle strengthening of the Cu(II)-S(Cys) interaction on replacing Met16 with Tyr, Trp, and Phe is indicated by the upshifted (0.3-0.8cm(-1)) RR bands involving nu(Cu-S)(Cys) stretching modes. In contrast, the RR spectra of Met16 mutants with aliphatic amino acids revealed larger (0.2-1.8cm(-1)) shifts of the nu(Cu-S)(Cys) stretching modes to a lower frequency region, which indicate a weakening of the Cu(II)-S(Cys) bond. Comparisons of the predominantly nu(Cu-S)(Cys) stretching RR peaks of the Met16X=Tyr, Trp, and Phe variants, with the molar absorptivity ratio epsilon(1)/epsilon(2) of sigma( approximately 455nm)/pi( approximately 595nm) (Cys)S-->Cu(II) charge-transfer bands in the optical spectrum and the axial/rhombic EPR signals, revealed a slightly more trigonal disposition of ligands about the copper(II) ion. In contrast, the RR spectra of Met16Z=Ala, Val, Leu, and Ile variants with aliphatic amino acid side chains show a more tetrahedral perturbation of the copper active site, as judged by the lower frequencies of the nu(Cu-S)(Cys) stretching modes, much larger values of the epsilon(1)/epsilon(2) ratio, and the increased rhombicity of the EPR spectra.
[Mh] Termos MeSH primário: Achromobacter cycloclastes
Azurina
Proteínas de Bactérias
Proteínas de Transporte
Metionina/genética
Mutação
[Mh] Termos MeSH secundário: Achromobacter cycloclastes/química
Achromobacter cycloclastes/genética
Azurina/química
Azurina/genética
Proteínas de Bactérias/química
Proteínas de Bactérias/genética
Proteínas de Transporte/química
Proteínas de Transporte/genética
Domínio Catalítico
Eletroquímica
Metaloproteínas/química
Metaloproteínas/genética
Metionina/metabolismo
Modelos Moleculares
Conformação Proteica
Análise Espectral Raman
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Carrier Proteins); 0 (Metalloproteins); 0 (copper-binding protein); 0 (pseudoazurin); 12284-43-4 (Azurin); AE28F7PNPL (Methionine)
[Em] Mês de entrada:1005
[Cu] Atualização por classe:131121
[Lr] Data última revisão:
131121
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:091217
[St] Status:MEDLINE
[do] DOI:10.1016/j.jinorgbio.2009.11.004


  5 / 17 MEDLINE  
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[PMID]:18939838
[Au] Autor:Yanagisawa S; Crowley PB; Firbank SJ; Lawler AT; Hunter DM; McFarlane W; Li C; Kohzuma T; Banfield MJ; Dennison C
[Ad] Endereço:Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
[Ti] Título:Pi-interaction tuning of the active site properties of metalloproteins.
[So] Source:J Am Chem Soc;130(46):15420-8, 2008 Nov 19.
[Is] ISSN:1520-5126
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The influence of pi-interactions with a His ligand have been investigated in a family of copper-containing redox metalloproteins. The Met16Phe and Met16Trp pseudoazurin, and Leu12Phe spinach and Leu14Phe Phormidium laminosum plastocyanin variants possess active-site pi-contacts between the introduced residue and His81 and His87/92 respectively. The striking overlap of the side chain of Phe16 in the Met16Phe variant and that of Met16 in wild type pseudoazurin identifies that this position provides an important second coordination sphere interaction in both cases. His-ligand protonation and dissociation from Cu(I) occurs in the wild type proteins resulting in diminished redox activity, providing a [H(+)]-driven switch for regulating electron transfer. The introduced pi-interaction has opposing effects on the pKa for the His ligand in pseudoazurin and plastocyanin due to subtle differences in the pi-contact, stabilizing the coordinated form of pseudoazurin whereas in plastocyanin protonation and dissociation is favored. Replacement of Pro36, a residue that has been suggested to facilitate structural changes upon His ligand protonation, with a Gly, has little effect on the pKa of His87 in spinach plastocyanin. The mutations at Met16 have a significant influence on the reduction potential of pseudoazurin. Electron self-exchange is enhanced, whereas association with the physiological partner, nitrite reductase, is only affected by the Met16Phe mutation, but kcat is halved in both the Met16Phe and Met16Trp variants. Protonation of the His ligand is the feature most affected by the introduction of a pi-interaction.
[Mh] Termos MeSH primário: Domínio Catalítico
Metaloproteínas/química
Metaloproteínas/metabolismo
[Mh] Termos MeSH secundário: Achromobacter cycloclastes/química
Achromobacter cycloclastes/genética
Achromobacter cycloclastes/metabolismo
Cobre/química
Cobre/metabolismo
Cristalografia por Raios X
Cianobactérias/química
Cianobactérias/genética
Cianobactérias/metabolismo
Dryopteris/química
Dryopteris/genética
Dryopteris/metabolismo
Elétrons
Concentração de Íons de Hidrogênio
Ligantes
Metaloproteínas/genética
Modelos Moleculares
Ressonância Magnética Nuclear Biomolecular
Oxirredução
Ligação Proteica
Estrutura Terciária de Proteína
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Ligands); 0 (Metalloproteins); 789U1901C5 (Copper)
[Em] Mês de entrada:0901
[Cu] Atualização por classe:170922
[Lr] Data última revisão:
170922
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:081023
[St] Status:MEDLINE
[do] DOI:10.1021/ja8038135


  6 / 17 MEDLINE  
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[PMID]:17681606
[Au] Autor:Fujita K; Chan JM; Bollinger JA; Alvarez ML; Dooley DM
[Ad] Endereço:Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, USA.
[Ti] Título:Anaerobic purification, characterization and preliminary mechanistic study of recombinant nitrous oxide reductase from Achromobacter cycloclastes.
[So] Source:J Inorg Biochem;101(11-12):1836-44, 2007 Nov.
[Is] ISSN:0162-0134
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:An overexpression system for nitrous oxide reductase (N(2)OR), an enzyme that catalyzes the conversion of N(2)O to N(2) and H(2)O, has been developed in Achromobacter cycloclastes. Anaerobically purified A. cycloclastes recombinant N(2)OR (AcN(2)OR) has on average 4.5 Cu and 1.2 S per monomer. Upon reduction by methyl viologen, AcN(2)OR displays a high specific activity: 124 U/mg at 25 degrees C. Anaerobically purified AcN(2)OR displays a unique absorption spectrum. UV-visible and EPR spectra, combined with kinetics studies, indicate that the as-purified form of the enzyme is predominately a mixture of the fully-reduced Cu(Z)=[4Cu(I)] state and the Cu(Z)=[3Cu(I).Cu(II)] state, with the latter readily reducible by reduced forms of viologens. CD spectra of the as-purified AcN(2)OR over a range of pH values reveal perturbations of the protein conformation induced by pH variations, although the principal secondary structure elements are largely unaltered. Further, the activity of AcN(2)OR in D(2)O is significantly decreased compared with that in H(2)O, indicative of a significant solvent isotope effect on N(2)O reduction. These data are in good agreement with conclusions reached in recent studies on the effect of pH on catalysis by N(2)OR [K. Fujita, D.M. Dooley, Inorg. Chem. 46 (2007) 613-615].
[Mh] Termos MeSH primário: Achromobacter cycloclastes/genética
Oxirredutases/química
Proteínas Recombinantes/química
Proteínas Recombinantes/isolamento & purificação
[Mh] Termos MeSH secundário: Anaerobiose
Catálise
Dicroísmo Circular
Cobre/química
Concentração de Íons de Hidrogênio
Cinética
Modelos Moleculares
Óxido Nitroso/metabolismo
Oxirredução
Oxirredutases/genética
Oxirredutases/metabolismo
Proteínas Recombinantes/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Recombinant Proteins); 789U1901C5 (Copper); EC 1.- (Oxidoreductases); EC 1.7.2.4 (nitrous oxide reductase); K50XQU1029 (Nitrous Oxide)
[Em] Mês de entrada:0801
[Cu] Atualização por classe:131121
[Lr] Data última revisão:
131121
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:070808
[St] Status:MEDLINE


  7 / 17 MEDLINE  
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[PMID]:17014077
[Au] Autor:Taubner LM; McGuirl MA; Dooley DM; Copié V
[Ad] Endereço:Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, USA.
[Ti] Título:Structural studies of Apo NosL, an accessory protein of the nitrous oxide reductase system: insights from structural homology with MerB, a mercury resistance protein.
[So] Source:Biochemistry;45(40):12240-52, 2006 Oct 10.
[Is] ISSN:0006-2960
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The formation of the unique catalytic tetranuclear copper cluster (Cu(Z)) of nitrous oxide reductase, N(2)OR, requires the coexpression of a multiprotein assembly apparatus encoded by the nosDFYL operon. NosL, one of the proteins encoded by this transcript, is a 20 kDa lipoprotein of the periplasm that has been shown to bind copper(I), although its function has yet to be detemined. Cu(I) EXAFS data collected on the holo protein demonstrated that features of the copper binding site are consistent with a role for this protein as a metallochaperone, a class of metal ion transporters involved in metal resistance, homeostasis, and metallocluster biosynthesis. To test this hypothesis and to gain insight into other potential functional roles for this protein in the N(2)OR system, the three-dimensional solution structure of apo NosL has been solved by solution NMR methods. The structure of apo NosL consists of two relatively independent homologous domains that adopt an unusual betabetaalphabeta topology. The fold of apo NosL displays structural homology to only one other protein, MerB, an organomercury lyase involved in bacterial mercury resistance (Di Lello et al. (2004) Biochemistry 43, 8322-32). The structural similarity between apo NosL and MerB, together with the absolute conservation of Met109 in all NosL sequences, indicates that this residue may be involved in copper ligation, and that the metal binding site is likely to be solvent-accessible and contiguous with a large binding cleft. The structural observations suggest that NosL is exceptionally adapted for a role in copper and/or sulfur delivery and possibly for metallochaperone function.
[Mh] Termos MeSH primário: Proteínas de Bactérias/química
Liases/química
Oxirredutases/química
[Mh] Termos MeSH secundário: Achromobacter cycloclastes/enzimologia
Sequência de Aminoácidos
Apoproteínas/química
Ligações de Hidrogênio
Modelos Moleculares
Dados de Sequência Molecular
Ressonância Magnética Nuclear Biomolecular
Estrutura Terciária de Proteína
Homologia de Sequência de Aminoácidos
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Apoproteins); 0 (Bacterial Proteins); EC 1.- (Oxidoreductases); EC 1.7.2.4 (nitrous oxide reductase); EC 4.- (Lyases); EC 4.99.1.2 (MerB protein, Bacteria)
[Em] Mês de entrada:0611
[Cu] Atualização por classe:120528
[Lr] Data última revisão:
120528
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:061004
[St] Status:MEDLINE


  8 / 17 MEDLINE  
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[PMID]:16904686
[Au] Autor:Paraskevopoulos K; Antonyuk SV; Sawers RG; Eady RR; Hasnain SS
[Ad] Endereço:School of Biomolecular Sciences, Liverpool John Moores University, Liverpool L3 5AF, UK.
[Ti] Título:Insight into catalysis of nitrous oxide reductase from high-resolution structures of resting and inhibitor-bound enzyme from Achromobacter cycloclastes.
[So] Source:J Mol Biol;362(1):55-65, 2006 Sep 08.
[Is] ISSN:0022-2836
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The difficult chemistry of nitrous oxide (N2O) reduction to gaseous nitrogen (N2) in biology is catalysed by the novel micro4-sulphide-bridged tetranuclear Cuz cluster of the N2O reductases (N2OR). Two spectroscopically distinct forms of this cluster have been identified as CuZ and CuZ*. We have obtained a 1.86 A resolution crystal structure of the pink-purple species of N2OR from Achromobacter cycloclastes (AcN2OR) isolated under aerobic conditions. This structure reveals a previously unobserved ligation with two oxygen atoms from H2O/OH- coordinated to Cu1 and Cu4 of the catalytic centre. We ascribe this structure to be that of the CuZ form of the cluster, since the previously reported structures of two blue species of N2ORs, also isolated aerobically, have characterised the redox inactive CuZ* form, revealing a single water molecule at Cu4. Exposure of the as-isolated AcN2OR to sodium iodide led to reduction of the electron-donating CuA site and the formation of a blue species. Structure determination of this adduct at 1.7 A resolution showed that iodide was bound at the CuZ site bridging the Cu1 and Cu4 ions. This structure represents the first observation of an inhibitor bound to the Cu1-Cu4 edge of the catalytic cluster, providing clear evidence for this being the catalytic edge in N2ORs. These structures, together with the published structural and spectroscopic data, give fresh insight into the mode of substrate binding, reduction and catalysis.
[Mh] Termos MeSH primário: Achromobacter cycloclastes/enzimologia
Oxirredutases/química
Oxirredutases/metabolismo
Estrutura Secundária de Proteína
Estrutura Terciária de Proteína
[Mh] Termos MeSH secundário: Sítios de Ligação
Cobre/química
Cristalografia por Raios X
Modelos Moleculares
Dados de Sequência Molecular
Óxido Nitroso/metabolismo
Oxirredução
Oxirredutases/antagonistas & inibidores
Oxirredutases/genética
Oxigênio/química
Ligação Proteica
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
789U1901C5 (Copper); EC 1.- (Oxidoreductases); EC 1.7.2.4 (nitrous oxide reductase); K50XQU1029 (Nitrous Oxide); S88TT14065 (Oxygen)
[Em] Mês de entrada:0611
[Cu] Atualização por classe:131121
[Lr] Data última revisão:
131121
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:060815
[St] Status:MEDLINE


  9 / 17 MEDLINE  
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[PMID]:16795108
[Au] Autor:Sato K; Dennison C
[Ad] Endereço:Institute for Cell and Molecular Biosciences, Medical School, University of Newcastle upon Tyne, Newcastle upon Tyne, NE2 4HH, UK.
[Ti] Título:Active site comparison of CoII blue and green nitrite reductases.
[So] Source:Chemistry;12(25):6647-59, 2006 Aug 25.
[Is] ISSN:0947-6539
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:Copper-containing nitrite reductases (NiRs) possess type 1 (T1) and type 2 (T2) copper sites and can be either green or blue in color owing to differences at their T1 centers. The active sites of a green and a blue NiR were studied by utilizing their T1CuI/T2CoII and T1CoII/T2CoII-substituted forms. The UV/Vis spectra of these derivatives highlight the similarity of the T2 centers in these enzymes and that T1 site differences are also present in the CoII forms. The paramagnetic NMR spectra of T1CuI/T2CoII enzymes allow hyperfine shifted resonances from the three T2 His ligands to be assigned: these exhibit remarkably similar positions in the spectra of both NiRs, emphasizing the homology of the T2 centers. The addition of nitrite results in subtle alterations in the paramagnetic NMR spectra of the T1CuI/T2CoII forms at pH<7, which indicate a geometry change upon the binding of substrate. Shifted resonances from all of the T1 site ligands have been assigned and the CoII--N(His) interactions are alike, whereas the CbetaH proton resonances of the Cys ligand exhibit subtle chemical shift differences in the blue and green NiRs. The strength of the axial CoII--S(Met) interaction is similar in the two NiRs studied, but the altered conformation of the side chain of this ligand results in a dramatically different chemical shift pattern for the CgammaH protons. This indicates an alteration in the bonding of the axial ligand in these derivatives, which could be influential in the CuII proteins.
[Mh] Termos MeSH primário: Cobalto/química
Cobalto/metabolismo
Metaloproteínas/química
Metaloproteínas/metabolismo
Nitrito Redutases/química
Nitrito Redutases/metabolismo
[Mh] Termos MeSH secundário: Achromobacter cycloclastes/enzimologia
Alcaligenes/enzimologia
Sítios de Ligação
Ressonância Magnética Nuclear Biomolecular
Espectrofotometria Ultravioleta
Temperatura Ambiente
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Metalloproteins); 3G0H8C9362 (Cobalt); EC 1.7.- (Nitrite Reductases)
[Em] Mês de entrada:0705
[Cu] Atualização por classe:131121
[Lr] Data última revisão:
131121
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:060624
[St] Status:MEDLINE


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[PMID]:16517672
[Au] Autor:Choi PS; Naal Z; Moore C; Casado-Rivera E; Abruña HD; Helmann JD; Shapleigh JP
[Ad] Endereço:Cornell University, Department of Microbiology, Wing Hall, Ithaca, NY 14853, USA.
[Ti] Título:Assessing the impact of denitrifier-produced nitric oxide on other bacteria.
[So] Source:Appl Environ Microbiol;72(3):2200-5, 2006 Mar.
[Is] ISSN:0099-2240
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:A series of experiments was undertaken to learn more about the impact on other bacteria of nitric oxide (NO) produced during denitrification. The denitrifier Rhodobacter sphaeroides 2.4.3 was chosen as a denitrifier for these experiments. To learn more about NO production by this bacterium, NO levels during denitrification were measured by using differential mass spectrometry. This revealed that NO levels produced during nitrate respiration by this bacterium were in the low muM range. This concentration of NO is higher than that previously measured in denitrifiers, including Achromobacter cycloclastes and Paracoccus denitrificans. Therefore, both 2.4.3 and A. cycloclastes were used in this work to compare the effects of various NO levels on nondenitrifying bacteria. By use of bacterial overlays, it was found that the NO generated by A. cycloclastes and 2.4.3 cells during denitrification inhibited the growth of both Bacillus subtilis and R. sphaeroides 2.4.1 but that R. sphaeroides 2.4.3 caused larger zones of inhibition in the overlays than A. cycloclastes. Both R. sphaeroides 2.4.3 and A. cycloclastes induced the expression of the NO stress response gene hmp in B. subtilis. Taken together, these results indicate that there is variability in the NO concentrations produced by denitrifiers, but, irrespective of the NO levels produced, microbes in the surrounding environment were responsive to the NO produced during denitrification.
[Mh] Termos MeSH primário: Achromobacter cycloclastes/metabolismo
Bacillus subtilis/efeitos dos fármacos
Nitratos/metabolismo
Óxido Nítrico/biossíntese
Rhodobacter sphaeroides/metabolismo
[Mh] Termos MeSH secundário: Bacillus subtilis/crescimento & desenvolvimento
Regulação Bacteriana da Expressão Gênica
Espectrometria de Massas
Óxido Nítrico/farmacologia
Rhodobacter sphaeroides/efeitos dos fármacos
Rhodobacter sphaeroides/crescimento & desenvolvimento
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Nitrates); 31C4KY9ESH (Nitric Oxide)
[Em] Mês de entrada:0605
[Cu] Atualização por classe:161019
[Lr] Data última revisão:
161019
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:060307
[St] Status:MEDLINE



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