Base de dados : MEDLINE
Pesquisa : B02.075.200.500 [Categoria DeCS]
Referências encontradas : 125 [refinar]
Mostrando: 1 .. 10   no formato [Detalhado]

página 1 de 13 ir para página                         

  1 / 125 MEDLINE  
              next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28591626
[Au] Autor:Rawle RA; Hamerly T; Tripet BP; Giannone RJ; Wurch L; Hettich RL; Podar M; Copié V; Bothner B
[Ad] Endereço:Department of Microbiology, Montana State University, Bozeman, MT 59717, United States; Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, United States.
[Ti] Título:Multi-omics analysis provides insight to the Ignicoccus hospitalis-Nanoarchaeum equitans association.
[So] Source:Biochim Biophys Acta;1861(9):2218-2227, 2017 09.
[Is] ISSN:0006-3002
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: Studies of interspecies interactions are inherently difficult due to the complex mechanisms which enable these relationships. A model system for studying interspecies interactions is the marine hyperthermophiles Ignicoccus hospitalis and Nanoarchaeum equitans. Recent independently-conducted 'omics' analyses have generated insights into the molecular factors modulating this association. However, significant questions remain about the nature of the interactions between these archaea. METHODS: We jointly analyzed multiple levels of omics datasets obtained from published, independent transcriptomics, proteomics, and metabolomics analyses. DAVID identified functionally-related groups enriched when I. hospitalis is grown alone or in co-culture with N. equitans. Enriched molecular pathways were subsequently visualized using interaction maps generated using STRING. RESULTS: Key findings of our multi-level omics analysis indicated that I. hospitalis provides precursors to N. equitans for energy metabolism. Analysis indicated an overall reduction in diversity of metabolic precursors in the I. hospitalis-N. equitans co-culture, which has been connected to the differential use of ribosomal subunits and was previously unnoticed. We also identified differences in precursors linked to amino acid metabolism, NADH metabolism, and carbon fixation, providing new insights into the metabolic adaptions of I. hospitalis enabling the growth of N. equitans. CONCLUSIONS: This multi-omics analysis builds upon previously identified cellular patterns while offering new insights into mechanisms that enable the I. hospitalis-N. equitans association. GENERAL SIGNIFICANCE: Our study applies statistical and visualization techniques to a mixed-source omics dataset to yield a more global insight into a complex system, that was not readily discernable from separate omics studies.
[Mh] Termos MeSH primário: Desulfurococcaceae/metabolismo
Nanoarchaeota/metabolismo
[Mh] Termos MeSH secundário: Aminoácidos/metabolismo
Metabolismo Energético
Metabolômica
NAD/metabolismo
Proteômica
Proteínas Ribossômicas/metabolismo
Transcriptoma
[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.
[Nm] Nome de substância:
0 (Amino Acids); 0 (Ribosomal Proteins); 0U46U6E8UK (NAD)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171108
[Lr] Data última revisão:
171108
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170608
[St] Status:MEDLINE


  2 / 125 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28025081
[Au] Autor:Shlaifer I; Quashie PK; Kim HY; Turnbull JL
[Ad] Endereço:Department of Chemistry and Biochemistry and the Centre for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke St. West, Montréal, Québec H4B 1R6, Canada.
[Ti] Título:Biochemical characterization of TyrA enzymes from Ignicoccus hospitalis and Haemophilus influenzae: A comparative study of the bifunctional and monofunctional dehydrogenase forms.
[So] Source:Biochim Biophys Acta;1865(3):312-320, 2017 03.
[Is] ISSN:0006-3002
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Biosynthesis of l-tyrosine (l-Tyr) is directed by the interplay of two enzymes. Chorismate mutase (CM) catalyzes the rearrangement of chorismate to prephenate, which is then converted to hydroxyphenylpyruvate by prephenate dehydrogenase (PD). This work reports the first characterization of the independently expressed PD domain of bifunctional CM-PD from the crenarchaeon Ignicoccus hospitalis and the first functional studies of both full-length CM-PD and the PD domain from the bacterium Haemophilus influenzae. All proteins were hexa-histidine tagged, expressed in Escherichia coli and purified. Expression and purification of I. hospitalis CM-PD generated a degradation product identified as a PD fragment lacking the protein's first 80 residues, Δ80CM-PD. A comparable stable PD domain could also be generated by limited tryptic digestion of this bifunctional enzyme. Thus, Δ80CM-PD constructs were prepared in both organisms. CM-PD and Δ80CM-PD from both organisms were dimeric and displayed the predicted enzymatic activities and thermal stabilities in accord with their hyperthermophilic and mesophilic origins. In contrast with H. influenzae PD activity which was NAD -specific and displayed >75% inhibition with 50µM l-Tyr, I. hospitalis PD demonstrated dual cofactor specificity with a preference for NADP and an insensitivity to l-Tyr. These properties are consistent with a model of the I. hospitalis PD domain based on the previously reported structure of the H. influenzae homolog. Our results highlight the similarities and differences between the archaeal and bacterial TyrA proteins and reveal that the PD activity of both prokaryotes can be successfully mapped to a functionally independent unit.
[Mh] Termos MeSH primário: Proteínas de Bactérias/metabolismo
Desulfurococcaceae/metabolismo
Haemophilus influenzae/metabolismo
Complexos Multienzimáticos/metabolismo
Prefenato Desidrogenase/metabolismo
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Corismato Mutase/metabolismo
Escherichia coli/metabolismo
Histidina/metabolismo
NAD/metabolismo
NADP/metabolismo
Tirosina/metabolismo
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Multienzyme Complexes); 0 (TyrA protein, Bacteria); 0U46U6E8UK (NAD); 42HK56048U (Tyrosine); 4QD397987E (Histidine); 53-59-8 (NADP); EC 1.3.1.12 (Prephenate Dehydrogenase); EC 5.4.99.5 (Chorismate Mutase)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170926
[Lr] Data última revisão:
170926
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161228
[St] Status:MEDLINE


  3 / 125 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


  4 / 125 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27290727
[Au] Autor:Shlaifer I; Turnbull JL
[Ad] Endereço:Department of Chemistry and Biochemistry, Concordia University, 7141 Sherbrooke St. West, Montréal, QC, H4B 1R6, Canada.
[Ti] Título:Characterization of two key enzymes for aromatic amino acid biosynthesis in symbiotic archaea.
[So] Source:Extremophiles;20(4):503-14, 2016 Jul.
[Is] ISSN:1433-4909
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:Biosynthesis of L-tyrosine (L-Tyr) and L-phenylalanine (L-Phe) is directed by the interplay of three enzymes. Chorismate mutase (CM) catalyzes the rearrangement of chorismate to prephenate, which can be either converted to hydroxyphenylpyruvate by prephenate dehydrogenase (PD) or to phenylpyruvate by prephenate dehydratase (PDT). This work reports the first characterization of a trifunctional PD-CM-PDT from the smallest hyperthermophilic archaeon Nanoarchaeum equitans and a bifunctional CM-PD from its host, the crenarchaeon Ignicoccus hospitalis. Hexa-histidine tagged proteins were expressed in Escherichia coli and purified by affinity chromatography. Specific activities determined for the trifunctional enzyme were 21, 80, and 30 U/mg for CM, PD, and PDT, respectively, and 47 and 21 U/mg for bifunctional CM and PD, respectively. Unlike most PDs, these two archaeal enzymes were insensitive to regulation by L-Tyr and preferred NADP(+) to NAD(+) as a cofactor. Both the enzymes were highly thermally stable and exhibited maximal activity at 90 °C. N. equitans PDT was feedback inhibited by L-Phe (Ki = 0.8 µM) in a non-competitive fashion consistent with L-Phe's combination at a site separate from that of prephenate. Our results suggest that PD from the unique symbiotic archaeal pair encompass a distinct subfamily of prephenate dehydrogenases with regard to their regulation and co-substrate specificity.
[Mh] Termos MeSH primário: Proteínas Arqueais/metabolismo
Corismato Mutase/metabolismo
Desulfurococcaceae/enzimologia
Nanoarchaeota/enzimologia
Prefenato Desidratase/metabolismo
Prefenato Desidrogenase/metabolismo
[Mh] Termos MeSH secundário: Aminoácidos Aromáticos/biossíntese
Proteínas Arqueais/química
Proteínas Arqueais/genética
Corismato Mutase/química
Corismato Mutase/genética
Desulfurococcaceae/fisiologia
Estabilidade Enzimática
Temperatura Alta
Nanoarchaeota/fisiologia
Nitrosaminas/metabolismo
Prefenato Desidratase/química
Prefenato Desidratase/genética
Prefenato Desidrogenase/química
Prefenato Desidrogenase/genética
Especificidade por Substrato
Simbiose
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Amino Acids, Aromatic); 0 (Archaeal Proteins); 0 (Nitrosamines); 91308-70-2 (N-nitroso-2-hydroxypropylamine); EC 1.3.1.12 (Prephenate Dehydrogenase); EC 4.2.1.51 (Prephenate Dehydratase); EC 5.4.99.5 (Chorismate Mutase)
[Em] Mês de entrada:1702
[Cu] Atualização por classe:171013
[Lr] Data última revisão:
171013
[Sb] Subgrupo de revista:IM; S
[Da] Data de entrada para processamento:160613
[St] Status:MEDLINE
[do] DOI:10.1007/s00792-016-0840-z


  5 / 125 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:26909878
[Au] Autor:Molina R; Besker N; Marcaida MJ; Montoya G; Prieto J; D'Abramo M
[Ad] Endereço:Structural Biology and Biocomputing Programme, Macromolecular Crystallography Group, Spanish National Cancer Research Centre (CNIO) , c/Melchor Fdez. Almagro 3, 28029 Madrid, Spain.
[Ti] Título:Key Players in I-DmoI Endonuclease Catalysis Revealed from Structure and Dynamics.
[So] Source:ACS Chem Biol;11(5):1401-7, 2016 05 20.
[Is] ISSN:1554-8937
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Homing endonucleases, such as I-DmoI, specifically recognize and cleave long DNA target sequences (∼20 bp) and are potentially powerful tools for genome manipulation. However, inefficient and off-target DNA cleavage seriously limits specific editing in complex genomes. One approach to overcome these limitations is to unambiguously identify the key structural players involved in catalysis. Here, we report the E117A I-DmoI mutant crystal structure at 2.2 Šresolution that, together with the wt and Q42A/K120M constructs, is combined with computational approaches to shed light on protein cleavage activity. The cleavage mechanism was related both to key structural effects, such as the position of water molecules and ions participating in the cleavage reaction, and to dynamical effects related to protein behavior. In particular, we found that the protein perturbation pattern significantly changes between cleaved and noncleaved DNA strands when the ions and water molecules are correctly positioned for the nucleophilic attack that initiates the cleavage reaction, in line with experimental enzymatic activity. The proposed approach paves the way for an effective, general, and reliable procedure to analyze the enzymatic activity of endonucleases from a very limited data set, i.e., structure and dynamics.
[Mh] Termos MeSH primário: Desoxirribonucleases de Sítio Específico do Tipo I/química
Desoxirribonucleases de Sítio Específico do Tipo I/metabolismo
Desulfurococcaceae/enzimologia
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Domínio Catalítico
Cristalografia por Raios X
DNA/metabolismo
Desoxirribonucleases de Sítio Específico do Tipo I/genética
Desulfurococcaceae/química
Desulfurococcaceae/metabolismo
Simulação de Dinâmica Molecular
Mutação Puntual
Conformação Proteica
Alinhamento de Sequência
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
9007-49-2 (DNA); EC 3.1.21.- (endodeoxyribonuclease I-Dmo I); EC 3.1.21.3 (Deoxyribonucleases, Type I Site-Specific)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:170404
[Lr] Data última revisão:
170404
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160225
[St] Status:MEDLINE
[do] DOI:10.1021/acschembio.5b00730


  6 / 125 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:26596623
[Au] Autor:Perevalova AA; Kublanov IV; Bidzhieva SKh; Mukhopadhyay B; Bonch-Osmolovskaya EA; Lebedinsky AV
[Ad] Endereço:1​ Winogradsky Institute of Microbiology, Research Center of Biotechnology, RAS, Leninsky pr. 33-2, 119071 Moscow, Russia.
[Ti] Título:Reclassification of Desulfurococcus mobilis as a synonym of Desulfurococcus mucosus, Desulfurococcus fermentans and Desulfurococcus kamchatkensis as synonyms of Desulfurococcus amylolyticus, and emendation of the D. mucosus and D. amylolyticus species descriptions.
[So] Source:Int J Syst Evol Microbiol;66(1):514-7, 2016 Jan.
[Is] ISSN:1466-5034
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Representatives of the crenarchaeal genus Desulfurococcus are strictly anaerobic hyperthermophiles with an organotrophic type of metabolism. Since 1982, five Desulfurococcus species names have been validly published: Desulfurococcus mucosus, D. mobilis, D. amylolyticus, D. fermentans and D. kamchatkensis. Recently, the genomic sequences of all five species became available, promoting the refinement of their taxonomic status. Analysis of full-length high-quality 16S rRNA gene sequences shows that the sequences of D. mobilis and D. mucosus are 100 % identical and differ by 2.2 % from those of D. amylolyticus, D. fermentans and D. kamchatkensis. The latter three sequences differ from each other by 0.1-0.3 % (99.9 % similarity in the D amylolyticus-D. kamchatkensis pair and 99.7 % in the pairs involving D. fermentans). In silico prediction of DNA-DNA hybridization (DDH) values by comparison of genomes using ggdc 2.0 blast+ at http://ggdc.dsmz.de/ produced results that correlated with the 16S rRNA gene sequence similarity values. In the D. mucosus-D. mobilis and D. amylolyticus-D. kamchatkensis pairs, the predicted DDH values were 99 and 92 %, respectively, much higher than the recommended 70 % species-delimiting DDH value. Between members of different pairs, these values were no higher than 20 %. For D. fermentans, its predicted DDH values were around 70 % with D. amylolyticus and D. kamchatkensis and no higher than 20 % with D. mobilis and D. mucosus. These results indicated that D. mobilis should be reclassified as a synonym of D. mucosus, whereas D. kamchatkensis and D. fermentans should be reclassified as synonyms of D. amylolyticus.
[Mh] Termos MeSH primário: Desulfurococcaceae/classificação
Fontes Termais/microbiologia
Filogenia
[Mh] Termos MeSH secundário: DNA Arqueal/genética
Desulfurococcaceae/genética
Desulfurococcaceae/isolamento & purificação
Islândia
Hibridização de Ácido Nucleico
RNA Ribossômico 16S/genética
Análise de Sequência de DNA
[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 (DNA, Archaeal); 0 (RNA, Ribosomal, 16S)
[Em] Mês de entrada:1606
[Cu] Atualização por classe:160211
[Lr] Data última revisão:
160211
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:151125
[St] Status:MEDLINE
[do] DOI:10.1099/ijsem.0.000747


  7 / 125 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
PubMed Central Texto completo
Texto completo
[PMID]:26880868
[Au] Autor:Hamerly T; Tripet B; Wurch L; Hettich RL; Podar M; Bothner B; Copié V
[Ad] Endereço:Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA.
[Ti] Título:Characterization of Fatty Acids in Crenarchaeota by GC-MS and NMR.
[So] Source:Archaea;2015:472726, 2015.
[Is] ISSN:1472-3654
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Lipids composed of condensed isoprenyl units connected to glycerol backbones by ether linkages are a distinguishing feature of Archaea. Data suggesting that fatty acids with linear hydrocarbon chains are present in some Archaea have been available for decades. However, lack of genomic and biochemical evidence for the metabolic machinery required to synthesize and degrade fatty acids has left the field unclear on this potentially significant biochemical aspect. Because lipids are energy currency and cell signaling molecules, their presence in Archaea is significant for understanding archaeal biology. A recent large-scale bioinformatics analysis reignited the debate as to the importance of fatty acids in Archaea by presenting genetic evidence for the presence of enzymes required for anabolic and catabolic fatty acid metabolism across the archaeal domain. Here, we present direct biochemical evidence from gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) spectroscopy for the presence of fatty acids in two members of the Crenarchaeota, Sulfolobus solfataricus and Ignicoccus hospitalis. This is the first report providing biochemical data for the existence of fatty acids in these Crenarchaeota, opening new discussions on energy balance and the potential for the discovery of new thermostable enzymes for industry.
[Mh] Termos MeSH primário: Desulfurococcaceae/química
Ácidos Graxos/análise
Cromatografia Gasosa-Espectrometria de Massas
Espectroscopia de Ressonância Magnética
Sulfolobus solfataricus/química
[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 (Fatty Acids)
[Em] Mês de entrada:1608
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160217
[St] Status:MEDLINE
[do] DOI:10.1155/2015/472726


  8 / 125 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:26219412
[Au] Autor:Slutskaya E; Artemova N; Kleymenov S; Petrova T; Popov V
[Ad] Endereço:A.N. Bakh Institute of Biochemistry, Russian Academy of Sciences, Leninsky pr. 33, Moscow, 119071, Russian Federation. elslutskaya@yandex.ru.
[Ti] Título:Heat-induced conformational changes of TET peptidase from crenarchaeon Desulfurococcus kamchatkensis.
[So] Source:Eur Biophys J;44(8):667-75, 2015 Dec.
[Is] ISSN:1432-1017
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:The effects of heating on the structure and stability of multimeric TET aminopeptidase (APDkam589) were studied by differential scanning calorimetry, tryptophan fluorescence quenching, and dynamic light scattering. Thermally induced structural changes in APDkam589 were found to occur in two phases: local conformational changes, which occur below 70 °C and are not associated with thermal denaturation of the protein, and global structural changes (above 70 °C) induced by irreversible thermal unfolding of the protein accompanied by its spontaneous aggregation. These results may explain the bell-shaped temperature dependence with a maximum at ~70 °C previously observed for enzymatic activity of APDkam589. Interestingly, the thermal unfolding of APDkam589 at about 81.2 °C is accompanied by a so-called blue-shift of about 10 nm-a shift of the Trp fluorescence spectrum toward shorter wavelength. From this point of view, APDkam589 is quite different from most proteins, which are characterized by a long wavelength shift of the spectrum ("red-shift") upon denaturation. The blue-shift of the Trp fluorescence spectrum reflects the changes in the environment of Trp residues, which becomes more hydrophobic upon denaturation. The molecular structure of APDkam589 was determined by X-ray diffraction. The monomer of APDkam589 has six Trp residues, five of which are on the external surface of the dodecamer. Therefore, the blue-shift of the Trp fluorescence spectrum can be explained, at least partly, by aggregation of APDkam589, which occurs simultaneously with its thermal denaturation and probably makes the environment of these Trp residues more hydrophobic.
[Mh] Termos MeSH primário: Aminopeptidases/química
Proteínas Arqueais/química
Desulfurococcaceae/enzimologia
Temperatura Alta
Desnaturação Proteica
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Estabilidade Enzimática
Dados de Sequência Molecular
Triptofano/química
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Archaeal Proteins); 8DUH1N11BX (Tryptophan); EC 3.4.11.- (Aminopeptidases)
[Em] Mês de entrada:1608
[Cu] Atualização por classe:170922
[Lr] Data última revisão:
170922
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150730
[St] Status:MEDLINE
[do] DOI:10.1007/s00249-015-1064-3


  9 / 125 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
PubMed Central Texto completo
Texto completo
[PMID]:25849365
[Au] Autor:Cahn JK; Brinkmann-Chen S; Spatzal T; Wiig JA; Buller AR; Einsle O; Hu Y; Ribbe MW; Arnold FH
[Ad] Endereço:Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, U.S.A.
[Ti] Título:Cofactor specificity motifs and the induced fit mechanism in class I ketol-acid reductoisomerases.
[So] Source:Biochem J;468(3):475-84, 2015 Jun 15.
[Is] ISSN:1470-8728
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Although most sequenced members of the industrially important ketol-acid reductoisomerase (KARI) family are class I enzymes, structural studies to date have focused primarily on the class II KARIs, which arose through domain duplication. In the present study, we present five new crystal structures of class I KARIs. These include the first structure of a KARI with a six-residue ß2αB (cofactor specificity determining) loop and an NADPH phosphate-binding geometry distinct from that of the seven- and 12-residue loops. We also present the first structures of naturally occurring KARIs that utilize NADH as cofactor. These results show insertions in the specificity loops that confounded previous attempts to classify them according to loop length. Lastly, we explore the conformational changes that occur in class I KARIs upon binding of cofactor and metal ions. The class I KARI structures indicate that the active sites close upon binding NAD(P)H, similar to what is observed in the class II KARIs of rice and spinach and different from the opening of the active site observed in the class II KARI of Escherichia coli. This conformational change involves a decrease in the bending of the helix that runs between the domains and a rearrangement of the nicotinamide-binding site.
[Mh] Termos MeSH primário: Alicyclobacillus/enzimologia
Azotobacter vinelandii/enzimologia
Proteínas de Bactérias/metabolismo
Coenzimas/metabolismo
Desulfurococcaceae/enzimologia
Cetol-Ácido Redutoisomerase/metabolismo
Modelos Moleculares
[Mh] Termos MeSH secundário: Adenosina Difosfato Ribose/análogos & derivados
Adenosina Difosfato Ribose/química
Adenosina Difosfato Ribose/metabolismo
Sequência de Aminoácidos
Proteínas de Bactérias/química
Proteínas de Bactérias/genética
Sítios de Ligação
Domínio Catalítico
Coenzimas/química
Cristalografia por Raios X
Cetol-Ácido Redutoisomerase/química
Cetol-Ácido Redutoisomerase/genética
Magnésio/química
Magnésio/metabolismo
Conformação Molecular
Dados de Sequência Molecular
Proteínas Mutantes/química
Proteínas Mutantes/metabolismo
NAD/química
NAD/metabolismo
NADP/química
NADP/metabolismo
Fosforilação
Dobramento de Proteína
Proteínas Recombinantes/química
Proteínas Recombinantes/metabolismo
Alinhamento de Sequência
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Coenzymes); 0 (Mutant Proteins); 0 (Recombinant Proteins); 0U46U6E8UK (NAD); 20762-30-5 (Adenosine Diphosphate Ribose); 53-59-8 (NADP); EC 1.1.1.86 (Ketol-Acid Reductoisomerase); I38ZP9992A (Magnesium)
[Em] Mês de entrada:1510
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150408
[St] Status:MEDLINE
[do] DOI:10.1042/BJ20150183


  10 / 125 MEDLINE  
              first record previous record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:25760701
[Au] Autor:Petrova TE; Slutskaya ES; Boyko KM; Sokolova OS; Rakitina TV; Korzhenevskiy DA; Gorbacheva MA; Bezsudnova EY; Popov VO
[Ad] Endereço:A. N. Bach Institute of Biochemistry, RAS, Leninsky pr. 33, Moscow 119071, Russian Federation.
[Ti] Título:Structure of the dodecamer of the aminopeptidase APDkam598 from the archaeon Desulfurococcus kamchatkensis.
[So] Source:Acta Crystallogr F Struct Biol Commun;71(Pt 3):277-85, 2015 Mar.
[Is] ISSN:2053-230X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The crystal structure of the aminopeptidase APDkam589 from the thermophilic crenarchaeon Desulfurococcus kamchatkensis was determined at a resolution of 3.0 Å. In the crystal, the monomer of APDkam589 and its symmetry-related monomers are densely packed to form a 12-subunit complex. Single-particle electron-microscopy analysis confirms that APDkam589 is present as a compact dodecamer in solution. The APDkam589 molecule is built similarly to the molecules of the PhTET peptidases, which have the highest sequence identity to APDkam589 among known structures and were isolated from the more thermostable archaeon Pyrococcus horikoshii. A comparison of the interactions of the subunits in APDkam589 with those in PhTET1, PhTET2 and PhTET3 reveals that APDkam589 has a much lower total number of salt bridges, which correlates with the lower thermostability of APDkam589. The monomer of APDkam589 has six Trp residues, five of which are on the external surface of the dodecamer. A superposition of the structure of APDkam589 with those having a high sequence similarity to APDkam589 reveals that, although the positions of Trp45, Trp252 and Trp358 are not conserved in the sequences, the spatial locations of the Trp residues in these models are similar.
[Mh] Termos MeSH primário: Aminopeptidases/química
Proteínas Arqueais/química
Desulfurococcaceae/enzimologia
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Domínio Catalítico
Sequência Conservada
Ligações de Hidrogênio
Dados de Sequência Molecular
Estrutura Quaternária de Proteína
Estrutura Secundária de Proteína
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Archaeal Proteins); EC 3.4.11.- (Aminopeptidases)
[Em] Mês de entrada:1512
[Cu] Atualização por classe:170301
[Lr] Data última revisão:
170301
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150312
[St] Status:MEDLINE
[do] DOI:10.1107/S2053230X15000783



página 1 de 13 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