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Pesquisa : B02.075.800.800 [Categoria DeCS]
Referências encontradas : 69 [refinar]
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[PMID]:27871372
[Au] Autor:Stekhanova TN; Rakitin AL; Mardanov AV; Bezsudnova EY; Popov VO
[Ad] Endereço:A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Ave. 33, bld. 2, 119071, Moscow, Russian Federation. Electronic address: tstekh@yandex.ru.
[Ti] Título:A Novel highly thermostable branched-chain amino acid aminotransferase from the crenarchaeon Vulcanisaeta moutnovskia.
[So] Source:Enzyme Microb Technol;96:127-134, 2017 Jan.
[Is] ISSN:1879-0909
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:A new fold-type IV branched-chain amino acid aminotransferase VMUT0738 from the hyperthermophilic Crenarchaeon Vulcanisaeta moutnovskia was successfully expressed in Escherichia coli. Purified VMUT0738 showed activity toward numerous aliphatic and aromatic l-amino acids and 2-oxo acids at optimal pH 8.0. Distinguishing features of the VMUT0738 compared with typical BCAT are the absence of activity toward acidic substrates, high activity toward basic ones, and low but detectable activity toward the (R)-enantiomer of α-methylbenzylamine (0.0076U/mg) The activity of VMUT0738 increases with a rise in the temperature from 60°C to 90°C. VMUT0738 showed high thermostability (after 24h incubation at 70°C the enzyme lost only 27% of the initial activity) and the resistance to organic solvents. The sequence alignment revealed two motifs (V/I)xLDxR and PFG(K/H)YL characteristic of BCATs from species of the related genera Vulcanisaeta, Pyrobaculum and Thermoproteus that might be responsible for the unique substrate recognition profile of the enzyme.
[Mh] Termos MeSH primário: Proteínas Arqueais/metabolismo
Thermoproteaceae/enzimologia
Transaminases/metabolismo
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Proteínas Arqueais/genética
Clonagem Molecular
Estabilidade Enzimática
Genes Arqueais
Concentração de Íons de Hidrogênio
Cinética
Proteínas Recombinantes/genética
Proteínas Recombinantes/metabolismo
Homologia de Sequência de Aminoácidos
Homologia Estrutural de Proteína
Especificidade por Substrato
Temperatura Ambiente
Thermoproteaceae/genética
Transaminases/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Archaeal Proteins); 0 (Recombinant Proteins); EC 2.6.1.- (Transaminases); EC 2.6.1.42 (branched-chain-amino-acid transaminase)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:170530
[Lr] Data última revisão:
170530
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161123
[St] Status:MEDLINE


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[PMID]:27037359
[Au] Autor:Urschel MR; Hamilton TL; Roden EE; Boyd ES
[Ad] Endereço:Department of Microbiology and Immunology and the Thermal Biology Institute, Montana State University, Bozeman, MT 59717, USA.
[Ti] Título:Substrate preference, uptake kinetics and bioenergetics in a facultatively autotrophic, thermoacidophilic crenarchaeote.
[So] Source:FEMS Microbiol Ecol;92(5):fiw069, 2016 May.
[Is] ISSN:1574-6941
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Facultative autotrophs are abundant components of communities inhabiting geothermal springs. However, the influence of uptake kinetics and energetics on preference for substrates is not well understood in this group of organisms. Here, we report the isolation of a facultatively autotrophic crenarchaeote, strain CP80, from Cinder Pool (CP, 88.7°C, pH 4.0), Yellowstone National Park. The 16S rRNA gene sequence from CP80 is 98.8% identical to that from Thermoproteus uzonensis and is identical to the most abundant sequence identified in CP sediments. Strain CP80 reduces elemental sulfur (S8°) and demonstrates hydrogen (H2)-dependent autotrophic growth. H2-dependent autotrophic activity is suppressed by amendment with formate at a concentration in the range of 20-40 µM, similar to the affinity constant determined for formate utilization. Synthesis of a cell during growth with low concentrations of formate required 0.5 µJ compared to 2.5 µJ during autotrophic growth with H2 These results, coupled to data indicating greater C assimilation efficiency when grown with formate as compared to carbon dioxide, are consistent with preferential use of formate for energetic reasons. Collectively, these results provide new insights into the kinetic and energetic factors that influence the physiology and ecology of facultative autotrophs in high-temperature acidic environments.
[Mh] Termos MeSH primário: Fontes Termais/microbiologia
Thermoproteaceae/isolamento & purificação
Thermoproteaceae/metabolismo
[Mh] Termos MeSH secundário: Processos Autotróficos
Dióxido de Carbono/metabolismo
Metabolismo Energético
Formiatos/metabolismo
Fontes Termais/química
Temperatura Alta
Hidrogênio/metabolismo
Cinética
Filogenia
RNA Arqueal/genética
RNA Ribossômico 16S/genética
Análise de Sequência de DNA
Enxofre/metabolismo
Thermoproteaceae/classificação
Thermoproteaceae/crescimento & desenvolvimento
Wyoming
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Formates); 0 (RNA, Archaeal); 0 (RNA, Ribosomal, 16S); 142M471B3J (Carbon Dioxide); 70FD1KFU70 (Sulfur); 7YNJ3PO35Z (Hydrogen)
[Em] Mês de entrada:1611
[Cu] Atualização por classe:161230
[Lr] Data última revisão:
161230
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160403
[St] Status:MEDLINE


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[PMID]:24858677
[Au] Autor:Kallnik V; Bunescu A; Sayer C; Bräsen C; Wohlgemuth R; Littlechild J; Siebers B
[Ad] Endereço:Molecular Enzyme Technology and Biochemistry, Biofilm Centre, Faculty of Chemistry, University of Duisburg-Essen, Universitaetsstrasse 5, 45141 Essen, Germany. Electronic address: Verena.Kallnik@uni-due.de.
[Ti] Título:Characterization of a phosphotriesterase-like lactonase from the hyperthermoacidophilic crenarchaeon Vulcanisaeta moutnovskia.
[So] Source:J Biotechnol;190:11-7, 2014 Nov 20.
[Is] ISSN:1873-4863
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:The phosphotriesterase-like lactonase (PLL) encoded by Vmut_2255 in the hyperthermoacidophilic crenarchaeon Vulcanisaeta moutnovskia (VmutPLL), represents the only hyperthermophilic PLL homologue identified so far in addition to the previously characterized thermophilic PLLs from Sulfolobus spp. The Vmut_2255 gene was cloned, heterologously expressed in Escherichia coli; the resultant protein purified and characterized as a 82kDa homodimer (36kDa subunits). The VmutPLL converted lactones and acyl-homoserine lactones (AHLs) with comparable activities. Towards organophosphates (OP) VmutPLL showed a promiscuous but significantly lower activity and only minor activity was observed with carboxylesters. The catalytic activity strictly depended on bivalent cations (Cd(2+)>Ni(2+)>Co(2+)>Mn(2+)>Zn(2+)). Furthermore, VmutPLL showed a pH optimum around 8.0, a temperature optimum of 80°C, and thermostability with a half-life of 26min at 90°C. In this work, the stereoselectivity of a PLL enzyme was investigated for the first time using enantiopure lactones. The VmutPLL showed a slight preference but not an exclusive specificity for the (R)-enantiomers of capro- and valerolactone. The high thermal stability as well as the broad substrate spectrum towards lactones, AHLs and OPs underlines the high biotechnological potential of VmutPLL.
[Mh] Termos MeSH primário: Hidrolases de Éster Carboxílico/metabolismo
Lactonas/metabolismo
Hidrolases de Triester Fosfórico/metabolismo
Thermoproteaceae/enzimologia
[Mh] Termos MeSH secundário: Hidrolases de Éster Carboxílico/genética
Cátions Bivalentes
Clonagem Molecular
Estabilidade Enzimática
Expressão Gênica
Concentração de Íons de Hidrogênio
Cinética
Especificidade por Substrato
Thermoproteaceae/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Cations, Divalent); 0 (Lactones); EC 3.1.1.- (Carboxylic Ester Hydrolases); EC 3.1.8.- (Phosphoric Triester Hydrolases)
[Em] Mês de entrada:1507
[Cu] Atualização por classe:141203
[Lr] Data última revisão:
141203
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:140527
[St] Status:MEDLINE


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[PMID]:23018780
[Au] Autor:Chan PP; Brown JW; Lowe TM
[Ad] Endereço:Department of Biomolecular Engineering, University of California Santa Cruz, CA, USA.
[Ti] Título:Modeling the Thermoproteaceae RNase P RNA.
[So] Source:RNA Biol;9(9):1155-60, 2012 Sep.
[Is] ISSN:1555-8584
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The RNA component of the RNase P complex is found throughout most branches of the tree of life and is principally responsible for removing the 5' leader sequence from pre-tRNA transcripts during tRNA maturation. RNase P RNA has a number of universal core features, however variations in sequence and structure found in homologs across the tree of life require multiple Rfam covariance search models to detect accurately. We describe a new Rfam search model to enable efficient detection of the diminutive archaeal Type T RNase P RNAs, which are missed by existing Rfam models. Using the new model, we establish effective score detection thresholds, and detect four new RNase P RNA genes in recently completed genomes from the crenarchaeal family Thermoproteaceae.
[Mh] Termos MeSH primário: Proteínas Arqueais/metabolismo
Modelos Moleculares
RNA Arqueal/metabolismo
Ribonuclease P/metabolismo
Thermoproteaceae/metabolismo
[Mh] Termos MeSH secundário: Proteínas Arqueais/química
Proteínas Arqueais/genética
Processamento Pós-Transcricional do RNA/fisiologia
RNA Arqueal/química
RNA Arqueal/genética
RNA de Transferência/genética
RNA de Transferência/metabolismo
Ribonuclease P/química
Ribonuclease P/genética
Thermoproteaceae/química
Thermoproteaceae/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Archaeal Proteins); 0 (RNA, Archaeal); 9014-25-9 (RNA, Transfer); EC 3.1.26.5 (Ribonuclease P)
[Em] Mês de entrada:1305
[Cu] Atualização por classe:150222
[Lr] Data última revisão:
150222
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:120929
[St] Status:MEDLINE
[do] DOI:10.4161/rna.21502


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[PMID]:12941964
[Au] Autor:Lorentzen E; Pohl E; Zwart P; Stark A; Russell RB; Knura T; Hensel R; Siebers B
[Ad] Endereço:European Molecular Biology Laboratory, Hamburg Outstation, Notkestrasse 85, D-22603 Hamburg, Germany.
[Ti] Título:Crystal structure of an archaeal class I aldolase and the evolution of (betaalpha)8 barrel proteins.
[So] Source:J Biol Chem;278(47):47253-60, 2003 Nov 21.
[Is] ISSN:0021-9258
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Fructose-1,6-bisphosphate aldolase (FBPA) catalyzes the reversible cleavage of fructose 1,6-bisphosphate to glyceraldehyde 3-phosphate and dihydroxyacetone phosphate in the glycolytic pathway. FBPAs from archaeal organisms have recently been identified and characterized as a divergent family of proteins. Here, we report the first crystal structure of an archaeal FBPA at 1.9-A resolution. The structure of this 280-kDa protein complex was determined using single wavelength anomalous dispersion followed by 10-fold non-crystallographic symmetry averaging and refined to an R-factor of 14.9% (Rfree 17.9%). The protein forms a dimer of pentamers, consisting of subunits adopting the ubiquitous (betaalpha)8 barrel fold. Additionally, a crystal structure of the archaeal FBPA covalently bound to dihydroxyacetone phosphate was solved at 2.1-A resolution. Comparison of the active site residues with those of classical FBPAs, which share no significant sequence identity but display the same overall fold, reveals a common ancestry between these two families of FBPAs. Structural comparisons, furthermore, establish an evolutionary link to the triosephosphate isomerases, a superfamily hitherto considered independent from the superfamily of aldolases.
[Mh] Termos MeSH primário: Proteínas Arqueais/química
Evolução Molecular
Frutose-Bifosfato Aldolase/química
[Mh] Termos MeSH secundário: Sítios de Ligação
Cristalografia por Raios X
Fosfato de Di-Hidroxiacetona/química
Estrutura Molecular
Conformação Proteica
Subunidades Proteicas/química
Thermoproteaceae/enzimologia
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Archaeal Proteins); 0 (Protein Subunits); 57-04-5 (Dihydroxyacetone Phosphate); EC 4.1.2.13 (Fructose-Bisphosphate Aldolase)
[Em] Mês de entrada:0402
[Cu] Atualização por classe:061115
[Lr] Data última revisão:
061115
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:030828
[St] Status:MEDLINE


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[PMID]:12798234
[Au] Autor:Prangishvili D
[Ad] Endereço:Lehrstuhl für Mikrobiologie und Archaeenzentrum, Universität Regensburg, Universitätsstr. 31, 93053 Regensburg, Germany. david.prangishvili@biologie.uni-r.de
[Ti] Título:Evolutionary insights from studies on viruses of hyperthermophilic archaea.
[So] Source:Res Microbiol;154(4):289-94, 2003 May.
[Is] ISSN:0923-2508
[Cp] País de publicação:France
[La] Idioma:eng
[Ab] Resumo:The morphological diversity of viruses which parasitize hyperthermophilic archaea thriving at temperatures > or = 80 degrees C appears to exceed that of viruses of prokaryotes living at lower temperatures. Based on assumptions of the existence of viruses in the prebiotic phase of evolution and hot origins of cellular life, we suggest that this remarkable diversity could have its source in ancestral diversity of viral morphotypes in hot environments. Attempts are made to trace evolutionary relationships of viruses of hyperthermophilic archaea with other viruses.
[Mh] Termos MeSH primário: Archaea/virologia
Vírus de Archaea/ultraestrutura
Evolução Biológica
[Mh] Termos MeSH secundário: Vírus de Archaea/fisiologia
Temperatura Alta
Sulfolobus/virologia
Thermoproteaceae/virologia
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; REVIEW
[Em] Mês de entrada:0310
[Cu] Atualização por classe:101118
[Lr] Data última revisão:
101118
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:030612
[St] Status:MEDLINE


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[PMID]:12768454
[Au] Autor:Itoh T; Nomura N; Sako Y
[Ad] Endereço:Japan Collection of Microorganisms, RIKEN (The Institute of Physical and Chemical Research), 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan. ito@jcm.riken.go.jp
[Ti] Título:Distribution of 16S rRNA introns among the family Thermoproteaceae and their evolutionary implications.
[So] Source:Extremophiles;7(3):229-33, 2003 Jun.
[Is] ISSN:1431-0651
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:Novel 16S rRNA introns were detected in four new strains within the family Thermoproteaceae. Pyrobaculum oguniense TE7(T) and Thermoproteus sp. IC-062 housed introns of 32 and 665-668 bp after positions 1205 and 1213 ( Escherichia coli numbering system), respectively. Caldivirga maquilingensis IC-167(T) had two introns of 37 and 140 bp after positions 901 and 908, respectively. Vulcanisaeta distributa IC-065 had a 691-bp intron after position 1391. All the introns larger than 650 bp encoded the LAGLI-DADG type proteins. The intron-encoded proteins of P. oguniense TE7(T) and Thermoproteus sp. IC-062 are cognate with the proteins encoded by introns inserted at the same position in other Pyrobaculum/ Thermoproteus strains and phylotypes. The intron-encoded protein of V. distributa IC-065 is partially related to that of a Pyrobaculum phylotype. A large-scale deletion in the second intron of Caldivirga maquilingensis IC-167(T) is suspected. Based on these newly found introns and hitherto known 16S rRNA introns, the evolutionary movements of the 16S rRNA introns and the encoded LAGLI-DADG type proteins are discussed.
[Mh] Termos MeSH primário: Íntrons
RNA Ribossômico 16S/genética
Thermoproteaceae/genética
[Mh] Termos MeSH secundário: Motivos de Aminoácidos
Archaea/genética
Sequência de Bases
Escherichia coli/genética
Evolução Molecular
Dados de Sequência Molecular
Fases de Leitura Aberta
Filogenia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (RNA, Ribosomal, 16S)
[Em] Mês de entrada:0402
[Cu] Atualização por classe:171013
[Lr] Data última revisão:
171013
[Sb] Subgrupo de revista:IM; S
[Da] Data de entrada para processamento:030528
[St] Status:MEDLINE


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[PMID]:12730226
[Au] Autor:Sartori AA; Jiricny J
[Ad] Endereço:Institute of Molecular Cancer Research, University of Zürich, August Forel-Strasse 7, Switzerland.
[Ti] Título:Enzymology of base excision repair in the hyperthermophilic archaeon Pyrobaculum aerophilum.
[So] Source:J Biol Chem;278(27):24563-76, 2003 Jul 04.
[Is] ISSN:0021-9258
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:DNA of all living organisms is constantly modified by exogenous and endogenous reagents. The mutagenic threat of modifications such as methylation, oxidation, and hydrolytic deamination of DNA bases is counteracted by base excision repair (BER). This process is initiated by the action of one of several DNA glycosylases, which removes the aberrant base and thus initiates a cascade of events that involves scission of the DNA backbone, removal of the baseless sugar-phosphate residue, filling in of the resulting single nucleotide gap, and ligation of the remaining nick. We were interested to find out how the BER process functions in hyperthermophiles, organisms growing at temperatures around 100 degrees C, where the rates of these spontaneous reactions are greatly accelerated. In our previous studies, we could show that the crenarchaeon Pyrobaculum aerophilum has at least three uracil-DNA glycosylases, Pa-UDGa, Pa-UDGb, and Pa-MIG, that can initiate the BER process by catalyzing the removal of uracil residues arising through the spontaneous deamination of cytosines. We now report that the genome of P. aerophilum encodes also the remaining functions necessary for BER and show that a system consisting of four P. aerophilum encoded enzymes, Pa-UDGb, AP endonuclease IV, DNA polymerase B2, and DNA ligase, can efficiently repair a G.U mispair in an oligonucleotide substrate to a G.C pair. Interestingly, the efficiency of the in vitro repair reaction was stimulated by Pa-PCNA1, the processivity clamp of DNA polymerases.
[Mh] Termos MeSH primário: DNA Glicosilases
Reparo do DNA
Thermoproteaceae/enzimologia
Thermoproteaceae/genética
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Pareamento de Bases
Carbono-Oxigênio Liases/genética
Carbono-Oxigênio Liases/metabolismo
DNA Ligases/genética
DNA Ligases/metabolismo
DNA Polimerase beta/genética
DNA Polimerase beta/metabolismo
DNA Arqueal/genética
DNA Liase (Sítios Apurínicos ou Apirimidínicos)
Dados de Sequência Molecular
N-Glicosil Hidrolases/genética
N-Glicosil Hidrolases/metabolismo
Alinhamento de Sequência
Temperatura Ambiente
Uracila-DNA Glicosidase
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (DNA, Archaeal); EC 2.7.7.- (DNA Polymerase beta); EC 3.2.2.- (DNA Glycosylases); EC 3.2.2.- (N-Glycosyl Hydrolases); EC 3.2.2.- (Uracil-DNA Glycosidase); EC 4.2.- (Carbon-Oxygen Lyases); EC 4.2.99.18 (DNA-(Apurinic or Apyrimidinic Site) Lyase); EC 6.5.1.- (DNA Ligases)
[Em] Mês de entrada:0308
[Cu] Atualização por classe:061115
[Lr] Data última revisão:
061115
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:030506
[St] Status:MEDLINE


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[PMID]:12668760
[Au] Autor:Mura C; Phillips M; Kozhukhovsky A; Eisenberg D
[Ad] Endereço:Howard Hughes Medical Institute, Molecular Biology Institute, and Department of Energy Institute for Genomics and Proteomics, 201 Boyer Hall Molecular Biology Institute, University of California, Box 951570, Los Angeles, CA 90095-1570, USA.
[Ti] Título:Structure and assembly of an augmented Sm-like archaeal protein 14-mer.
[So] Source:Proc Natl Acad Sci U S A;100(8):4539-44, 2003 Apr 15.
[Is] ISSN:0027-8424
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:To better understand the roles of Sm proteins in forming the cores of many RNA-processing ribonucleoproteins, we determined the crystal structure of an atypical Sm-like archaeal protein (SmAP3) in which the conserved Sm domain is augmented by a previously uncharacterized, mixed alpha/beta C-terminal domain. The structure reveals an unexpected SmAP3 14-mer that is perforated by a cylindrical pore and is bound to 14 cadmium (Cd(2+)) ions. Individual heptamers adopt either "apical" or "equatorial" conformations that chelate Cd(2+) differently. SmAP3 forms supraheptameric oligomers (SmAP3)(n = 7,14,28) in solution, and assembly of the asymmetric 14-mer is modulated by differential divalent cation-binding in apical and equatorial subunits. Phylogenetic and sequence analyses substantiate SmAP3s as a unique subset of SmAPs. These results distinguish SmAP3s from other Sm proteins and provide a model for the structure and properties of Sm proteins >100 residues in length, e.g., several human Sm proteins.
[Mh] Termos MeSH primário: Proteínas Arqueais/química
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Proteínas Arqueais/genética
Proteínas Arqueais/metabolismo
Sítios de Ligação
Fenômenos Biofísicos
Biofísica
Cádmio/metabolismo
Seres Humanos
Ligantes
Modelos Moleculares
Dados de Sequência Molecular
Conformação Proteica
Estrutura Quaternária de Proteína
Estrutura Terciária de Proteína
Subunidades Proteicas
Homologia de Sequência de Aminoácidos
Eletricidade Estática
Thermoproteaceae/química
Thermoproteaceae/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.; RESEARCH SUPPORT, U.S. GOV'T, P.H.S.
[Nm] Nome de substância:
0 (Archaeal Proteins); 0 (Ligands); 0 (Protein Subunits); 0 (SmAP protein, Pyrobaculum aerophilum); 00BH33GNGH (Cadmium)
[Em] Mês de entrada:0306
[Cu] Atualização por classe:170219
[Lr] Data última revisão:
170219
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:030402
[St] Status:MEDLINE


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[PMID]:12654928
[Au] Autor:Johnsen U; Hansen T; Schonheit P
[Ad] Endereço:Institut für Allgemeine Mikrobiologie, Christian-Albrechts-Universität Kiel, Am Botanischen Garten 1-9, Kiel D-24118, Germany.
[Ti] Título:Comparative analysis of pyruvate kinases from the hyperthermophilic archaea Archaeoglobus fulgidus, Aeropyrum pernix, and Pyrobaculum aerophilum and the hyperthermophilic bacterium Thermotoga maritima: unusual regulatory properties in hyperthermophilic archaea.
[So] Source:J Biol Chem;278(28):25417-27, 2003 Jul 11.
[Is] ISSN:0021-9258
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Pyruvate kinases (PK, EC 2.7.1.40) from three hyperthermophilic archaea (Archaeoglobus fulgidus strain 7324, Aeropyrum pernix, and Pyrobaculum aerophilum) and from the hyperthermophilic bacterium Thermotoga maritima were compared with respect to their thermophilic, kinetic, and regulatory properties. PKs from the archaea are 200-kDa homotetramers composed of 50-kDa subunits. The enzymes required divalent cations, Mg2+ and Mn2+ being most effective, but were independent of K+. Temperature optima for activity were 85 degrees C (A. fulgidus) and above 98 degrees C (A. pernix and P. aerophilum). The PKs were highly thermostable up to 110 degrees C (A. pernix) and showed melting temperatures for thermal unfolding at 93 degrees C (A. fulgidus) or above 98 degrees C (A. pernix and P. aerophilum). All archaeal PKs exhibited sigmoidal saturation kinetics with phosphoenolpyruvate (PEP) and ADP indicating positive homotropic cooperative response with both substrates. Classic heterotropic allosteric regulators of PKs from eukarya and bacteria, e.g. fructose 1,6-bisphosphate or AMP, did not affect PK activity of hyperthermophilic archaea, suggesting the absence of heterotropic allosteric regulation. PK from the bacterium T. maritima is also a homotetramer of 50-kDa subunits. The enzyme was independent of K+ ions, had a temperature optimum of 80 degrees C, was highly thermostable up to 90 degrees C, and had a melting temperature above 98 degrees C. The enzyme showed cooperative response to PEP and ADP. In contrast to its archaeal counterparts, the T. maritima enzyme exhibited the classic allosteric response to the activator AMP and to the inhibitor ATP. Sequences of hyperthermophilic PKs showed significant similarity to characterized PKs from bacteria and eukarya. Phylogenetic analysis of PK sequences of all three domains indicates a distinct archaeal cluster that includes the PK from the hyperthermophilic bacterium T. maritima.
[Mh] Termos MeSH primário: Proteínas Arqueais/fisiologia
Archaeoglobus fulgidus/enzimologia
Desulfurococcaceae/enzimologia
Piruvato Quinase/química
Thermoproteaceae/enzimologia
Thermotoga maritima/enzimologia
[Mh] Termos MeSH secundário: Difosfato de Adenosina/farmacologia
Sítio Alostérico
Sequência de Aminoácidos
Catálise
Cátions
Dicroísmo Circular
Clonagem Molecular
Relação Dose-Resposta a Droga
Concentração de Íons de Hidrogênio
Íons
Cinética
Dados de Sequência Molecular
Fases de Leitura Aberta
Filogenia
Potássio/metabolismo
Piruvato Quinase/fisiologia
Proteínas Recombinantes/metabolismo
Homologia de Sequência de Aminoácidos
Temperatura Ambiente
Fatores de Tempo
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Archaeal Proteins); 0 (Cations); 0 (Ions); 0 (Recombinant Proteins); 61D2G4IYVH (Adenosine Diphosphate); EC 2.7.1.40 (Pyruvate Kinase); RWP5GA015D (Potassium)
[Em] Mês de entrada:0308
[Cu] Atualização por classe:131121
[Lr] Data última revisão:
131121
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:030326
[St] Status:MEDLINE



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