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[PMID]:28302400
[Au] Autor:Phillips RS; Anderson AD; Gentry HG; Güner OF; Bowen JP
[Ad] Endereço:Department of Chemistry, University of Georgia, Athens 30602, Georgia; Department of Biochemistry and Molecular Biology, University of Georgia, Athens 30602, Georgia. Electronic address: plp@uga.edu.
[Ti] Título:Substrate and inhibitor specificity of kynurenine monooxygenase from Cytophaga hutchinsonii.
[So] Source:Bioorg Med Chem Lett;27(8):1705-1708, 2017 04 15.
[Is] ISSN:1464-3405
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Kynurenine monooxygenase (KMO) is a potential drug target for treatment of neurodegenerative disorders such as Huntington's and Alzheimer's diseases. We have evaluated substituted kynurenines as substrates or inhibitors of KMO from Cytophaga hutchinsonii. Kynurenines substituted with a halogen at the 5-position are excellent substrates, with values of k and k /K comparable to or higher than kynurenine. However, kynurenines substituted in the 3-position are competitive inhibitors, with K values lower than the K for kynurenine. Bromination also enhances inhibition, and 3,5-dibromokynurenine is a potent competitive inhibitor with a K value of 1.5µM. A pharmacophore model of KMO was developed, and predicted that 3,4-dichlorohippuric acid would be an inhibitor. The K for this compound was found to be 34µM, thus validating the pharmacophore model. We are using these results and our model to design more potent inhibitors of KMO.
[Mh] Termos MeSH primário: Cytophaga/enzimologia
Inibidores Enzimáticos/química
Inibidores Enzimáticos/farmacologia
Quinurenina 3-Mono-Oxigenase/antagonistas & inibidores
Cinurenina/análogos & derivados
Cinurenina/farmacologia
[Mh] Termos MeSH secundário: Inibidores Enzimáticos/metabolismo
Halogenação
Seres Humanos
Cinética
Cinurenina/metabolismo
Quinurenina 3-Mono-Oxigenase/metabolismo
Modelos Moleculares
Doenças Neurodegenerativas/tratamento farmacológico
Doenças Neurodegenerativas/enzimologia
Doenças Neurodegenerativas/metabolismo
Especificidade por Substrato
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Enzyme Inhibitors); 343-65-7 (Kynurenine); EC 1.14.13.9 (Kynurenine 3-Monooxygenase)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:171124
[Lr] Data última revisão:
171124
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170318
[St] Status:MEDLINE


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[PMID]:27822737
[Au] Autor:Zhang C; Wang X; Zhang W; Zhao Y; Lu X
[Ad] Endereço:State Key Laboratory of Microbial Technology, College of Life Science, Shandong University, Jinan, 250100, China.
[Ti] Título:Expression and characterization of a glucose-tolerant ß-1,4-glucosidase with wide substrate specificity from Cytophaga hutchinsonii.
[So] Source:Appl Microbiol Biotechnol;101(5):1919-1926, 2017 Mar.
[Is] ISSN:1432-0614
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:Cytophaga hutchinsonii is a gram-negative bacterium that can efficiently degrade crystalline cellulose by a novel strategy without cell-free cellulases or cellulosomes. Genomic analysis implied that C. hutchinsonii had endoglucanases and ß-glucosidases but no exoglucanases which could processively digest cellulose and produce cellobiose. In this study, BglA was functionally expressed in Escherichia coli and found to be a ß-glucosidase with wide substrate specificity. It can hydrolyze pNPG, pNPC, cellobiose, and cellodextrins. Moreover, unlike most ß-glucosidases whose activity greatly decreases with increasing length of the substrate chains, BglA has similar activity on cellobiose and larger cellodextrins. The K values of BglA on cellobiose, cellotriose, and cellotetraose were calculated to be 4.8 × 10 , 5.6 × 10 , and 5.3 × 10 mol/l, respectively. These properties give BglA a great advantage to cooperate with endoglucanases in C. hutchinsonii in cellulose degradation. We proposed that C. hutchinsonii could utilize a simple cellulase system which consists of endoglucanases and ß-glucosidases to completely digest amorphous cellulose into glucose. Moreover, BglA was also found to be highly tolerant to glucose as it retained 40 % activity when the concentration of glucose was 100 times higher than that of the substrate, showing potential application in the bioenergy industry.
[Mh] Termos MeSH primário: Celulose/metabolismo
Cytophaga/enzimologia
Escherichia coli/metabolismo
beta-Glucosidase/genética
beta-Glucosidase/metabolismo
[Mh] Termos MeSH secundário: Celobiose/biossíntese
Celulose/análogos & derivados
Cytophaga/metabolismo
Dextrinas/metabolismo
Escherichia coli/genética
Glucose/metabolismo
Engenharia de Proteínas
Proteínas Recombinantes/genética
Proteínas Recombinantes/metabolismo
Especificidade por Substrato
Tetroses/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Dextrins); 0 (Recombinant Proteins); 0 (Tetroses); 16462-44-5 (Cellobiose); 38819-01-1 (cellotetraose); 9004-34-6 (Cellulose); 9061-30-7 (cellodextrin); EC 3.2.1.21 (beta-Glucosidase); IY9XDZ35W2 (Glucose)
[Em] Mês de entrada:1702
[Cu] Atualização por classe:170227
[Lr] Data última revisão:
170227
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161109
[St] Status:MEDLINE
[do] DOI:10.1007/s00253-016-7927-4


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[PMID]:27742681
[Au] Autor:Wang S; Zhao D; Bai X; Zhang W; Lu X
[Ad] Endereço:State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, China.
[Ti] Título:Identification and Characterization of a Large Protein Essential for Degradation of the Crystalline Region of Cellulose by Cytophaga hutchinsonii.
[So] Source:Appl Environ Microbiol;83(1), 2017 Jan 01.
[Is] ISSN:1098-5336
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Cytophaga hutchinsonii is a Gram-negative bacterium that can efficiently degrade crystalline cellulose by a unique mechanism different from the free cellulase or cellulosome strategy. In this study, chu_3220, encoding the hypothetical protein CHU_3220 (205 kDa), was identified by insertional mutation and gene deletion as the first gene essential for degradation of the crystalline region but not the amorphous region of cellulose by C. hutchinsonii A chu_3220 deletion mutant was defective in the degradation of crystalline cellulose and increased the degree of crystallinity of Avicel PH101 but could still degrade amorphous cellulose completely. CHU_3220 was found to be located on the outer surface of the outer membrane and could bind to cellulose. It contains 15 PbH1 domains and a C-terminal domain (CHU_C) that was proved to be critical for the localization of CHU_3220 on the cell surface and the function of CHU_3220 in crystalline cellulose degradation. Moreover, the degradation of crystalline cellulose was intact-cell dependent and inhibited by NaN Further study showed that chu_3220 was induced by cellulose and that the endoglucanase activity on the cell surface was significantly reduced without chu_3220 Real-time PCR revealed that the transcription of most genes encoding endoglucanases located on the cell surface was decreased in the chu_3220 deletion mutant, indicating that chu_3220 might also play a role in the regulation of the expression of some endoglucanases. IMPORTANCE: Cytophaga hutchinsonii could efficiently degrade crystalline cellulose with a unique mechanism without cellulosomes and free cellulases. It lacks proteins that are thought to play important roles in disruption of the crystalline region of cellulose, including exoglucanases, lytic polysaccharide monooxygenases, expansins, expansin-like proteins, or swollenins, and most of its endoglucanases lack carbohydrate binding modules. The mechanism of the degradation of crystalline cellulose is still unknown. In this study, chu_3220 was identified as the first gene essential for the degradation of the crystalline region but not the amorphous region of cellulose. CHU_3220 is a high-molecular-weight protein located on the outer surface of the outer membrane and could bind to cellulose. We proposed that CHU_3220 might be an essential component of a protein complex on the cell surface in charge of the decrystallization of crystalline cellulose. The degradation of crystalline cellulose by C. hutchinsonii was not only dependent on intact cells but also required the energy supplied by the cells. This was obviously different from other known cellulose depolymerization system. Our study has shed more light on the novel strategy of crystalline cellulose degradation by C. hutchinsonii.
[Mh] Termos MeSH primário: Proteínas da Membrana Bacteriana Externa/genética
Proteínas da Membrana Bacteriana Externa/metabolismo
Celulose/metabolismo
Cytophaga/metabolismo
[Mh] Termos MeSH secundário: Proteínas da Membrana Bacteriana Externa/isolamento & purificação
Celulase/metabolismo
Celulose/química
Cristalização
Cytophaga/genética
Deleção de Genes
Mutagênese Insercional
Reação em Cadeia da Polimerase em Tempo Real
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Outer Membrane Proteins); 9004-34-6 (Cellulose); EC 3.2.1.4 (Cellulase)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171102
[Lr] Data última revisão:
171102
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161016
[St] Status:MEDLINE


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[PMID]:27861619
[Au] Autor:Hoque MR; Ishizuka T; Inoue K; Abe-Yoshizumi R; Igarashi H; Mishima T; Kandori H; Yawo H
[Ad] Endereço:Department of Developmental Biology and Neuroscience, Tohoku University Graduate School of Life Sciences, Sendai, 980-8577, Japan.
[Ti] Título:A Chimera Na+-Pump Rhodopsin as an Effective Optogenetic Silencer.
[So] Source:PLoS One;11(11):e0166820, 2016.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:With the progress of optogenetics, the activities of genetically identified neurons can be optically silenced to determine whether the neurons in question are necessary for the network performance of the behavioral expression. This logical induction is expected to be improved by the application of the Na+ pump rhodopsins (NaRs), which hyperpolarize the membrane potential with negligible influence on the ionic/pH balance. Here, we made several chimeric NaRs between two NaRs, KR2 and IaNaR from Krokinobacter eikastus and Indibacter alkaliphilus, respectively. We found that one of these chimeras, named I1K6NaR, exhibited some improvements in the membrane targeting and photocurrent properties over native NaRs. The I1K6NaR-expressing cortical neurons were stably silenced by green light irradiation for a certain long duration. With its rapid kinetics and voltage dependency, the photoactivation of I1K6NaR would specifically counteract the generation of action potentials with less hyperpolarization of the neuronal membrane potential than KR2.
[Mh] Termos MeSH primário: Optogenética
Rodopsina/genética
Rodopsina/metabolismo
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Animais
Transporte Biológico
Linhagem Celular
Cytophaga/genética
Cytophaga/metabolismo
Fenômenos Eletrofisiológicos
Expressão Gênica
Íons/metabolismo
Luz
Potenciais da Membrana/efeitos da radiação
Neurônios/metabolismo
Neurônios/efeitos da radiação
Ratos
Rodopsina/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Ions); 9009-81-8 (Rhodopsin)
[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:161119
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0166820


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[PMID]:27260354
[Au] Autor:Zhu Y; Han L; Hefferon KL; Silvaggi NR; Wilson DB; McBride MJ
[Ad] Endereço:Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA.
[Ti] Título:Periplasmic Cytophaga hutchinsonii Endoglucanases Are Required for Use of Crystalline Cellulose as the Sole Source of Carbon and Energy.
[So] Source:Appl Environ Microbiol;82(15):4835-45, 2016 Aug 01.
[Is] ISSN:1098-5336
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:UNLABELLED: The soil bacterium Cytophaga hutchinsonii actively digests crystalline cellulose by a poorly understood mechanism. Genome analyses identified nine genes predicted to encode endoglucanases with roles in this process. No predicted cellobiohydrolases, which are usually involved in the utilization of crystalline cellulose, were identified. Chromosomal deletions were performed in eight of the endoglucanase-encoding genes: cel5A, cel5B, cel5C, cel9A, cel9B, cel9C, cel9E, and cel9F Each mutant retained the ability to digest crystalline cellulose, although the deletion of cel9C caused a modest decrease in cellulose utilization. Strains with multiple deletions were constructed to identify the critical cellulases. Cells of a mutant lacking both cel5B and cel9C were completely deficient in growth on cellulose. Cell fractionation and biochemical analyses indicate that Cel5B and Cel9C are periplasmic nonprocessive endoglucanases. The requirement of periplasmic endoglucanases for cellulose utilization suggests that cellodextrins are transported across the outer membrane during this process. Bioinformatic analyses predict that Cel5A, Cel9A, Cel9B, Cel9D, and Cel9E are secreted across the outer membrane by the type IX secretion system, which has been linked to cellulose utilization. These secreted endoglucanases may perform the initial digestion within amorphous regions on the cellulose fibers, releasing oligomers that are transported into the periplasm for further digestion by Cel5B and Cel9C. The results suggest that both cell surface and periplasmic endoglucanases are required for the growth of C. hutchinsonii on cellulose and that novel cell surface proteins may solubilize and transport cellodextrins across the outer membrane. IMPORTANCE: The bacterium Cytophaga hutchinsonii digests crystalline cellulose by an unknown mechanism. It lacks processive cellobiohydrolases that are often involved in cellulose digestion. Critical cellulolytic enzymes were identified by genetic analyses. Intracellular (periplasmic) nonprocessive endoglucanases performed an important role in cellulose utilization. The results suggest a model involving partial digestion at the cell surface, solubilization and uptake of cellodextrins across the outer membrane by an unknown mechanism, and further digestion within the periplasm. The ability to sequester cellodextrins and digest them intracellularly may limit losses of soluble cellobiose to other organisms. C. hutchinsonii uses an unusual approach to digest cellulose and is a potential source of novel proteins to increase the efficiency of conversion of cellulose into soluble sugars and biofuels.
[Mh] Termos MeSH primário: Proteínas de Bactérias/metabolismo
Celobiose/metabolismo
Celulase/metabolismo
Cytophaga/enzimologia
Periplasma/enzimologia
[Mh] Termos MeSH secundário: Proteínas de Bactérias/genética
Carbono/metabolismo
Celobiose/química
Celulase/genética
Cytophaga/genética
Cytophaga/metabolismo
Metabolismo Energético
Periplasma/genética
Periplasma/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 16462-44-5 (Cellobiose); 7440-44-0 (Carbon); EC 3.2.1.4 (Cellulase)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170922
[Lr] Data última revisão:
170922
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160605
[St] Status:MEDLINE
[do] DOI:10.1128/AEM.01298-16


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[PMID]:26773084
[Au] Autor:Zhou H; Wang X; Yang T; Zhang W; Chen G; Liu W
[Ad] Endereço:State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, China Nanlou Respiratory Diseases Department, Chinese PLA General Hospital, Haidian District, Beijing, China.
[Ti] Título:An Outer Membrane Protein Involved in the Uptake of Glucose Is Essential for Cytophaga hutchinsonii Cellulose Utilization.
[So] Source:Appl Environ Microbiol;82(6):1933-44, 2016 Jan 15.
[Is] ISSN:1098-5336
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Cytophaga hutchinsonii specializes in cellulose digestion by employing a collection of novel cell-associated proteins. Here, we identified a novel gene locus, CHU_1276, that is essential for C. hutchinsonii cellulose utilization. Disruption of CHU_1276 in C. hutchinsonii resulted in complete deficiency in cellulose degradation, as well as compromised assimilation of cellobiose or glucose at a low concentration. Further analysis showed that CHU_1276 was an outer membrane protein that could be induced by cellulose and low concentrations of glucose. Transcriptional profiling revealed that CHU_1276 exerted a profound effect on the genome-wide response to both glucose and Avicel and that the mutant lacking CHU_1276 displayed expression profiles very different from those of the wild-type strain under different culture conditions. Specifically, comparison of their transcriptional responses to cellulose led to the identification of a gene set potentially regulated by CHU_1276. These results suggest that CHU_1276 plays an essential role in cellulose utilization, probably by coordinating the extracellular hydrolysis of cellulose substrate with the intracellular uptake of the hydrolysis product in C. hutchinsonii.
[Mh] Termos MeSH primário: Proteínas da Membrana Bacteriana Externa/metabolismo
Celulose/metabolismo
Cytophaga/metabolismo
Glucose/metabolismo
[Mh] Termos MeSH secundário: Proteínas da Membrana Bacteriana Externa/genética
Celobiose/metabolismo
Cytophaga/genética
Perfilação da Expressão Gênica
Técnicas de Inativação de Genes
Hidrólise
Regulon
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Outer Membrane Proteins); 16462-44-5 (Cellobiose); 9004-34-6 (Cellulose); IY9XDZ35W2 (Glucose)
[Em] Mês de entrada:1612
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160117
[St] Status:MEDLINE
[do] DOI:10.1128/AEM.03939-15


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[PMID]:26745366
[Au] Autor:Grueneberg J; Engelen AH; Costa R; Wichard T
[Ad] Endereço:Institute for Inorganic and Analytical Chemistry, Jena School for Microbial Communication, Friedrich Schiller University Jena, Jena, Germany.
[Ti] Título:Macroalgal Morphogenesis Induced by Waterborne Compounds and Bacteria in Coastal Seawater.
[So] Source:PLoS One;11(1):e0146307, 2016.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Axenic gametes of the marine green macroalga Ulva mutabilis Føyn (Ria Formosa, locus typicus) exhibit abnormal development into slow-growing callus-like colonies with aberrant cell walls. Under laboratory conditions, it was previously demonstrated that all defects in growth and thallus development can be completely abolished when axenic gametes are inoculated with a combination of two specific bacterial strains originally identified as Roseobacter sp. strain MS2 and Cytophaga sp. strain MS6. These bacteria release diffusible morphogenetic compounds (= morphogens), which act similar to cytokinin and auxin. To investigate the ecological relevance of the waterborne bacterial morphogens, seawater samples were collected in the Ria Formosa lagoon (Algarve, Southern Portugal) at 20 sampling sites and tidal pools to assess their morphogenetic effects on the axenic gametes of U. mutabilis. Specifically the survey revealed that sterile-filtered seawater samples can completely recover growth and morphogenesis of U. mutabilis under axenic conditions. Morphogenetic activities of free-living and epiphytic bacteria isolated from the locally very abundant Ulva species (i.e., U. rigida) were screened using a multiwell-based testing system. The most represented genera isolated from U. rigida were Alteromonas, Pseudoalteromonas and Sulfitobacter followed by Psychrobacter and Polaribacter. Several naturally occurring bacterial species could emulate MS2 activity (= induction of cell divisions) regardless of taxonomic affiliation, whereas the MS6 activity (= induction of cell differentiation and cell wall formation) was species-specific and is probably a feature of difficult-to-culture bacteria. Interestingly, isolated bacteroidetes such as Algoriphagus sp. and Polaribacter sp. could individually trigger complete Ulva morphogenesis and thus provide a novel mode of action for bacterial-induced algal development. This study also highlights that the accumulation of algal growth factors in a shallow water body separated from the open ocean by barrier islands might have strong implications to, for example, the wide usage of natural coastal seawater in algal (land based) aquacultures of Ulva.
[Mh] Termos MeSH primário: Células Germinativas/efeitos dos fármacos
Morfogênese/efeitos dos fármacos
Reguladores de Crescimento de Planta/farmacologia
Ulva/efeitos dos fármacos
[Mh] Termos MeSH secundário: Alteromonas/classificação
Alteromonas/metabolismo
Cultura Axênica
Bacteroidetes/classificação
Bacteroidetes/metabolismo
Diferenciação Celular/efeitos dos fármacos
Divisão Celular/efeitos dos fármacos
Cytophaga/classificação
Cytophaga/metabolismo
Células Germinativas/crescimento & desenvolvimento
Células Germinativas/microbiologia
Morfogênese/fisiologia
Filogenia
Reguladores de Crescimento de Planta/biossíntese
Reguladores de Crescimento de Planta/secreção
Portugal
Psychrobacter/classificação
Psychrobacter/metabolismo
Roseobacter/classificação
Roseobacter/metabolismo
Água do Mar
Ulva/crescimento & desenvolvimento
Ulva/microbiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Plant Growth Regulators)
[Em] Mês de entrada:1606
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160109
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0146307


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[PMID]:26649736
[Au] Autor:Yang T; Bu X; Han Q; Wang X; Zhou H; Chen G; Zhang W; Liu W
[Ad] Endereço:State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, No. 27 Shanda South Road, Jinan, 250100, Shandong, People's Republic of China.
[Ti] Título:A small periplasmic protein essential for Cytophaga hutchinsonii cellulose digestion.
[So] Source:Appl Microbiol Biotechnol;100(4):1935-44, 2016 Feb.
[Is] ISSN:1432-0614
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:Cytophaga hutchinsonii is a gliding cellulolytic bacterium that is ubiquitously distributed in soil. The mechanism by which C. hutchinsonii achieves cellulose digestion, however, is still largely unknown. In this study, we obtained a C. hutchinsonii mutant that was defective in utilizing filter paper or Avicel as the sole carbon source by transposon mutagenesis. The interrupted gene locus, CHU_2981, encodes a hypothetical protein with only 130 amino acids. Cell fractionation and western blot detection of CHU_2981 fused with a C-terminal green fluorescence protein (GFP) indicated that CHU_2981 is located in the periplasm. The CHU_2981-disrupted mutant cells exhibited a significant growth defect on Avicel but not on glucose and cellobiose. The absence of CHU_2981 also resulted in a significant defect in colony spreading and individual cell motility compared to wild-type cells. Further analysis demonstrated that the CHU_2981-disrupted mutant cells exhibited a different profile of cellulose-absorbed outer membrane proteins from that of wild-type cells, in which protein varieties and amounts were markedly decreased. Our results showed that CHU_2981, the periplasmic non-cellulolytic protein, plays an important role in both cellulose utilization and cell motility probably by being involved in the appropriate production of outer membrane proteins.
[Mh] Termos MeSH primário: Celulose/metabolismo
Cytophaga/enzimologia
Cytophaga/metabolismo
Proteínas Periplásmicas/metabolismo
[Mh] Termos MeSH secundário: Cytophaga/genética
Elementos de DNA Transponíveis
Técnicas de Inativação de Genes
Hidrólise
Mutagênese Insercional
Proteínas Periplásmicas/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (DNA Transposable Elements); 0 (Periplasmic Proteins); 9004-34-6 (Cellulose)
[Em] Mês de entrada:1610
[Cu] Atualização por classe:161230
[Lr] Data última revisão:
161230
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:151210
[St] Status:MEDLINE
[do] DOI:10.1007/s00253-015-7204-y


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[PMID]:26169628
[Au] Autor:Zhang C; Zhang W; Lu X
[Ad] Endereço:State Key Laboratory of Microbial Technology, College of Life Science, Shandong University, Jinan, 250100, China.
[Ti] Título:Expression and characteristics of a Ca²âº-dependent endoglucanase from Cytophaga hutchinsonii.
[So] Source:Appl Microbiol Biotechnol;99(22):9617-23, 2015 Nov.
[Is] ISSN:1432-0614
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:Cytophaga hutchinsonii is a Gram-negative bacterium that can degrade crystalline cellulose efficiently with an unknown strategy. Genomic analysis suggested it lacks exoglucanases which are found in many cellulolytic organisms and most of the cellulases in C. hutchinsonii lack recognizable carbohydrate-binding modules (CBMs). CHU_1280, speculated to be an endoglucanase belonging to glycoside hydrolase family 9 (GH9) in C. hutchinsonii, was functionally expressed in Escherichia coli, and evidence was presented suggesting that it may be a processive endoglucanase. In the absence of Ca(2+), CHU_1280 was inactive. But in the presence of Ca(2+), it had a specific activity of 600 U/µmol with carboxymethyl cellulose (CMC) as the substrate. With Ca(2+), CHU_1280 hydrolyzed regenerated amorphous cellulose (RAC) with nearly 80 % of the reducing ends appearing in the soluble fraction, suggesting it degraded cellulose in a processive way. CHU_1280 could bind to cellulose without recognizable CBMs and its binding ability was also Ca(2+)-dependent. Ca(2+) could stabilize the catalytic domain at high temperature, but the denaturation temperature of the whole protein was decreased. C. hutchinsonii might have an exoglucanase-independent cellulases system which included endoglucanases, processive endoglucanases, and ß-glucosidases.
[Mh] Termos MeSH primário: Cálcio/metabolismo
Celulase/genética
Celulase/metabolismo
Celulose/metabolismo
Cytophaga/enzimologia
[Mh] Termos MeSH secundário: Cytophaga/genética
Ativadores de Enzimas/metabolismo
Estabilidade Enzimática
Escherichia coli/genética
Escherichia coli/metabolismo
Expressão Gênica
Proteínas Recombinantes/química
Proteínas Recombinantes/genética
Proteínas Recombinantes/metabolismo
Temperatura Ambiente
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Enzyme Activators); 0 (Recombinant Proteins); 9004-34-6 (Cellulose); EC 3.2.1.4 (Cellulase); SY7Q814VUP (Calcium)
[Em] Mês de entrada:1608
[Cu] Atualização por classe:151031
[Lr] Data última revisão:
151031
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150715
[St] Status:MEDLINE
[do] DOI:10.1007/s00253-015-6746-3


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[PMID]:26066317
[Au] Autor:Li Z; Zhang C; Wang S; Cao J; Zhang W; Lu X
[Ad] Endereço:State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan 250100, China.
[Ti] Título:A new locus in Cytophaga hutchinsonii involved in colony spreading on agar surfaces and individual cell gliding.
[So] Source:FEMS Microbiol Lett;362(14), 2015 Jul.
[Is] ISSN:1574-6968
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Cytophaga hutchinsonii glides rapidly over surfaces by an unknown mechanism without flagella and type IV pili and it can degrade crystalline cellulose efficiently by a novel mechanism. Tn4351 transposon mutagenesis was used to identify a new gene, CHU_1798, essential for colony spreading on agar surfaces. Further study showed that disruption of CHU_1798 caused non-spreading colonies on both soft and hard agar surfaces and individual cells were partially deficient in gliding on glass surfaces. The CHU_1798 mutant could digest cellulose as long as the cells were in direct contact with the cellulose, but it could not degrade cellulose powder buried in the agar plate. Scanning electron microscopy showed that individual mutant cells arranged irregularly on the cellulose fiber surface at an early stage of incubation, but later showed a regular parallel arrangement when there were plenty of cells and could spread along the cellulose fibers. These results suggest that CHU_1798 plays an important role in the motility of C. hutchinsonii and provide insight into the relation between cell motility and cellulose degradation.
[Mh] Termos MeSH primário: Cytophaga/genética
Cytophaga/fisiologia
Genes Bacterianos
[Mh] Termos MeSH secundário: Ágar
Celulose/metabolismo
Elementos de DNA Transponíveis
Movimento
Mutagênese
Mutação
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (DNA Transposable Elements); 9002-18-0 (Agar); 9004-34-6 (Cellulose)
[Em] Mês de entrada:1605
[Cu] Atualização por classe:150711
[Lr] Data última revisão:
150711
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150613
[St] Status:MEDLINE



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