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Piezophilic Phenotype Is Growth Condition Dependent and Correlated with the Regulation of Two Sets of ATPase in Deep-Sea Piezophilic Bacterium Photobacterium profundum SS9. Microorganisms 2023; 11:microorganisms11030637. [PMID: 36985211 PMCID: PMC10054830 DOI: 10.3390/microorganisms11030637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 02/25/2023] [Accepted: 02/28/2023] [Indexed: 03/06/2023] Open
Abstract
Alteration of respiratory components as a function of pressure is a common strategy developed in deep-sea microorganisms, presumably to adapt to high hydrostatic pressure (HHP). While the electron transport chain and terminal reductases have been extensively studied in deep-sea bacteria, little is known about their adaptations for ATP generation. In this study, we showed that the deep-sea bacterium Photobacterium profundum SS9 exhibits a more pronounced piezophilic phenotype when grown in minimal medium supplemented with glucose (MG) than in the routinely used MB2216 complex medium. The intracellular ATP level varied with pressure, but with opposite trends in the two culture media. Between the two ATPase systems encoded in SS9, ATPase-I played a dominant role when cultivated in MB2216, whereas ATPase-II was more abundant in the MG medium, especially at elevated pressure when cells had the lowest ATP level among all conditions tested. Further analyses of the ΔatpI, ΔatpE1 and ΔatpE2 mutants showed that disrupting ATPase-I induced expression of ATPase-II and that the two systems are functionally redundant in MB2216. Collectively, we provide the first examination of the differences and relationships between two ATPase systems in a piezophilic bacterium, and expanded our understanding of the involvement of energy metabolism in pressure adaptation.
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Lamelas FJ. Compressed-tube pressure cell for optical studies at ocean pressures: Application to glucose mutarotation kinetics. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:124101. [PMID: 28040945 DOI: 10.1063/1.4971417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A self-contained compressed-tube pressure cell is tested to 25 MPa. The cell is very simple to construct and offers stable pressure control with optical access to fluid samples. The physical path length of light through the cell is large enough to measure optical activity. The entire system is relatively small and portable, and it is vibration-free, since a compressor is not used. Operation of the cell is demonstrated by measuring the mutarotation rate of aqueous glucose solutions at 25 °C. A logarithmic plot of the rate constant vs. pressure yields an activation volume for mutarotation of -22 cm3/mol, approximately twice the value measured previously at higher pressures.
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Affiliation(s)
- F J Lamelas
- Department of Earth, Environment, and Physics, Worcester State University, 486 Chandler St., Worcester, Massachusetts 01602, USA
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Zhang SD, Santini CL, Zhang WJ, Barbe V, Mangenot S, Guyomar C, Garel M, Chen HT, Li XG, Yin QJ, Zhao Y, Armengaud J, Gaillard JC, Martini S, Pradel N, Vidaud C, Alberto F, Médigue C, Tamburini C, Wu LF. Genomic and physiological analysis reveals versatile metabolic capacity of deep-sea Photobacterium phosphoreum ANT-2200. Extremophiles 2016; 20:301-10. [PMID: 27039108 DOI: 10.1007/s00792-016-0822-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 03/01/2016] [Indexed: 10/22/2022]
Abstract
Bacteria of the genus Photobacterium thrive worldwide in oceans and show substantial eco-physiological diversity including free-living, symbiotic and piezophilic life styles. Genomic characteristics underlying this variability across species are poorly understood. Here we carried out genomic and physiological analysis of Photobacterium phosphoreum strain ANT-2200, the first deep-sea luminous bacterium of which the genome has been sequenced. Using optical mapping we updated the genomic data and reassembled it into two chromosomes and a large plasmid. Genomic analysis revealed a versatile energy metabolic potential and physiological analysis confirmed its growth capacity by deriving energy from fermentation of glucose or maltose, by respiration with formate as electron donor and trimethlyamine N-oxide (TMAO), nitrate or fumarate as electron acceptors, or by chemo-organo-heterotrophic growth in rich media. Despite that it was isolated at a site with saturated dissolved oxygen, the ANT-2200 strain possesses four gene clusters coding for typical anaerobic enzymes, the TMAO reductases. Elevated hydrostatic pressure enhances the TMAO reductase activity, mainly due to the increase of isoenzyme TorA1. The high copy number of the TMAO reductase isoenzymes and pressure-enhanced activity might imply a strategy developed by bacteria to adapt to deep-sea habitats where the instant TMAO availability may increase with depth.
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Affiliation(s)
- Sheng-Da Zhang
- Deep-Sea Microbial Cell Biology, Department of Deep Sea Sciences, Sanya Institute of Deep-Sea Science and Engineering, Chinese Academy of Sciences, Sanya, China.,France-China Bio-Mineralization and Nano-Structure Laboratory (LIA-BioMNSL), LCB-CNRS, Marseille, France/SIDSSE-CAS, Sanya, China
| | - Claire-Lise Santini
- LCB UMR 7257, Aix-Marseille Université, CNRS, IMM, 31, Chemin Joseph Aiguier, 13402, Marseille Cedex 20, France.,France-China Bio-Mineralization and Nano-Structure Laboratory (LIA-BioMNSL), LCB-CNRS, Marseille, France/SIDSSE-CAS, Sanya, China
| | - Wei-Jia Zhang
- Deep-Sea Microbial Cell Biology, Department of Deep Sea Sciences, Sanya Institute of Deep-Sea Science and Engineering, Chinese Academy of Sciences, Sanya, China.,France-China Bio-Mineralization and Nano-Structure Laboratory (LIA-BioMNSL), LCB-CNRS, Marseille, France/SIDSSE-CAS, Sanya, China
| | | | | | - Charlotte Guyomar
- LCB UMR 7257, Aix-Marseille Université, CNRS, IMM, 31, Chemin Joseph Aiguier, 13402, Marseille Cedex 20, France.,France-China Bio-Mineralization and Nano-Structure Laboratory (LIA-BioMNSL), LCB-CNRS, Marseille, France/SIDSSE-CAS, Sanya, China
| | - Marc Garel
- Aix-Marseille Université, Université du Sud Toulon-Var, CNRS/INSU, IRD, Mediterranean Institute of Oceanography (MIO), UM110, 13288, Marseille, France
| | - Hai-Tao Chen
- Deep-Sea Microbial Cell Biology, Department of Deep Sea Sciences, Sanya Institute of Deep-Sea Science and Engineering, Chinese Academy of Sciences, Sanya, China.,France-China Bio-Mineralization and Nano-Structure Laboratory (LIA-BioMNSL), LCB-CNRS, Marseille, France/SIDSSE-CAS, Sanya, China
| | - Xue-Gong Li
- Deep-Sea Microbial Cell Biology, Department of Deep Sea Sciences, Sanya Institute of Deep-Sea Science and Engineering, Chinese Academy of Sciences, Sanya, China.,France-China Bio-Mineralization and Nano-Structure Laboratory (LIA-BioMNSL), LCB-CNRS, Marseille, France/SIDSSE-CAS, Sanya, China
| | - Qun-Jian Yin
- Deep-Sea Microbial Cell Biology, Department of Deep Sea Sciences, Sanya Institute of Deep-Sea Science and Engineering, Chinese Academy of Sciences, Sanya, China.,France-China Bio-Mineralization and Nano-Structure Laboratory (LIA-BioMNSL), LCB-CNRS, Marseille, France/SIDSSE-CAS, Sanya, China
| | - Yuan Zhao
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | | | | | - Séverine Martini
- Aix-Marseille Université, Université du Sud Toulon-Var, CNRS/INSU, IRD, Mediterranean Institute of Oceanography (MIO), UM110, 13288, Marseille, France
| | - Nathalie Pradel
- Aix-Marseille Université, Université du Sud Toulon-Var, CNRS/INSU, IRD, Mediterranean Institute of Oceanography (MIO), UM110, 13288, Marseille, France
| | | | - François Alberto
- LCB UMR 7257, Aix-Marseille Université, CNRS, IMM, 31, Chemin Joseph Aiguier, 13402, Marseille Cedex 20, France.,France-China Bio-Mineralization and Nano-Structure Laboratory (LIA-BioMNSL), LCB-CNRS, Marseille, France/SIDSSE-CAS, Sanya, China
| | - Claudine Médigue
- Laboratoire d'Analyse Bioinformatique en Génomique et Métabolisme, CEA/DSV/IG/Genoscope and CNRS-UMR 8030 and Univ. Evry Val d'Esssone, Evry, France
| | - Christian Tamburini
- Aix-Marseille Université, Université du Sud Toulon-Var, CNRS/INSU, IRD, Mediterranean Institute of Oceanography (MIO), UM110, 13288, Marseille, France
| | - Long-Fei Wu
- LCB UMR 7257, Aix-Marseille Université, CNRS, IMM, 31, Chemin Joseph Aiguier, 13402, Marseille Cedex 20, France. .,France-China Bio-Mineralization and Nano-Structure Laboratory (LIA-BioMNSL), LCB-CNRS, Marseille, France/SIDSSE-CAS, Sanya, China.
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4
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Genome sequence of Vibrio diabolicus and identification of the exopolysaccharide HE800 biosynthesis locus. Appl Microbiol Biotechnol 2014; 98:10165-76. [PMID: 25273176 DOI: 10.1007/s00253-014-6086-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 09/01/2014] [Accepted: 09/03/2014] [Indexed: 01/08/2023]
Abstract
Vibrio diabolicus, a marine bacterium originating from deep-sea hydrothermal vents, produces the HE800 exopolysaccharide with high value for biotechnological purposes, especially for human health. Its genome was sequenced and analyzed; phylogenetic analysis using the core genome revealed V. diabolicus is close to another deep-sea Vibrio sp. (Ex25) within the Harveyi clade and Alginolyticus group. A genetic locus homologous to the syp cluster from Vibrio fischeri was demonstrated to be involved in the HE800 production. However, few genetic particularities suggest that the regulation of syp expression may be different in V. diabolicus. The presence of several types of glycosyltransferases within the locus indicates a capacity to generate diversity in the glycosidic structure, which may confer an adaptability to environmental conditions. These results contribute to better understanding exopolysaccharide biosynthesis and for developing new efficient processes to produce this molecule for biotechnological applications.
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Espaillat A, Carrasco-López C, Bernardo-García N, Pietrosemoli N, Otero LH, Álvarez L, de Pedro MA, Pazos F, Davis BM, Waldor MK, Hermoso JA, Cava F. Structural basis for the broad specificity of a new family of amino-acid racemases. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2014; 70:79-90. [PMID: 24419381 PMCID: PMC4984259 DOI: 10.1107/s1399004713024838] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 09/05/2013] [Indexed: 02/02/2023]
Abstract
Broad-spectrum amino-acid racemases (Bsrs) enable bacteria to generate noncanonical D-amino acids, the roles of which in microbial physiology, including the modulation of cell-wall structure and the dissolution of biofilms, are just beginning to be appreciated. Here, extensive crystallographic, mutational, biochemical and bioinformatic studies were used to define the molecular features of the racemase BsrV that enable this enzyme to accommodate more diverse substrates than the related PLP-dependent alanine racemases. Conserved residues were identified that distinguish BsrV and a newly defined family of broad-spectrum racemases from alanine racemases, and these residues were found to be key mediators of the multispecificity of BrsV. Finally, the structural analysis of an additional Bsr that was identified in the bioinformatic analysis confirmed that the distinguishing features of BrsV are conserved among Bsr family members.
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Affiliation(s)
- Akbar Espaillat
- Centro de Biología Molecular ‘Severo Ochoa’, Universidad Autónoma de Madrid–Consejo Superior de Investigaciones Científicas (CSIC), 28049 Madrid, Spain
- Department of Molecular Biology and Laboratory for Molecular Infection Medicine Sweden, Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
| | - César Carrasco-López
- Department of Crystallography and Structural Biology, Instituto de Química-Física ‘Rocasolano’–CSIC, 28006 Madrid, Spain
| | - Noelia Bernardo-García
- Department of Crystallography and Structural Biology, Instituto de Química-Física ‘Rocasolano’–CSIC, 28006 Madrid, Spain
| | | | - Lisandro H. Otero
- Department of Crystallography and Structural Biology, Instituto de Química-Física ‘Rocasolano’–CSIC, 28006 Madrid, Spain
| | - Laura Álvarez
- Centro de Biología Molecular ‘Severo Ochoa’, Universidad Autónoma de Madrid–Consejo Superior de Investigaciones Científicas (CSIC), 28049 Madrid, Spain
- Department of Molecular Biology and Laboratory for Molecular Infection Medicine Sweden, Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
| | - Miguel A. de Pedro
- Centro de Biología Molecular ‘Severo Ochoa’, Universidad Autónoma de Madrid–Consejo Superior de Investigaciones Científicas (CSIC), 28049 Madrid, Spain
| | | | - Brigid M. Davis
- Division of Infectious Diseases, Brigham and Women’s Hospital and Department of Microbiology and Immunobiology, Harvard Medical School and HHMI, Boston, MA 02115, USA
| | - Matthew K. Waldor
- Division of Infectious Diseases, Brigham and Women’s Hospital and Department of Microbiology and Immunobiology, Harvard Medical School and HHMI, Boston, MA 02115, USA
| | - Juan A. Hermoso
- Department of Crystallography and Structural Biology, Instituto de Química-Física ‘Rocasolano’–CSIC, 28006 Madrid, Spain
| | - Felipe Cava
- Centro de Biología Molecular ‘Severo Ochoa’, Universidad Autónoma de Madrid–Consejo Superior de Investigaciones Científicas (CSIC), 28049 Madrid, Spain
- Department of Molecular Biology and Laboratory for Molecular Infection Medicine Sweden, Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
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6
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Le Bihan T, Rayner J, Roy MM, Spagnolo L. Photobacterium profundum under pressure: a MS-based label-free quantitative proteomics study. PLoS One 2013; 8:e60897. [PMID: 23741291 PMCID: PMC3669370 DOI: 10.1371/journal.pone.0060897] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 03/04/2013] [Indexed: 11/19/2022] Open
Abstract
Photobacterium profundum SS9 is a Gram-negative bacterium, originally collected from the Sulu Sea. Its genome consists of two chromosomes and a 80 kb plasmid. Although it can grow under a wide range of pressures, P. profundum grows optimally at 28 MPa and 15°C. Its ability to grow at atmospheric pressure allows for both easy genetic manipulation and culture, making it a model organism to study piezophily. Here, we report a shotgun proteomic analysis of P. profundum grown at atmospheric compared to high pressure using label-free quantitation and mass spectrometry analysis. We have identified differentially expressed proteins involved in high pressure adaptation, which have been previously reported using other methods. Proteins involved in key metabolic pathways were also identified as being differentially expressed. Proteins involved in the glycolysis/gluconeogenesis pathway were up-regulated at high pressure. Conversely, several proteins involved in the oxidative phosphorylation pathway were up-regulated at atmospheric pressure. Some of the proteins that were differentially identified are regulated directly in response to the physical impact of pressure. The expression of some proteins involved in nutrient transport or assimilation, are likely to be directly regulated by pressure. In a natural environment, different hydrostatic pressures represent distinct ecosystems with their own particular nutrient limitations and abundances. However, the only variable considered in this study was atmospheric pressure.
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Affiliation(s)
- Thierry Le Bihan
- SynthSys, The University of Edinburgh, Edinburgh, United Kingdom
- Institute of Structural and Molecular Biology, University of Edinburgh, Edinburgh, United Kingdom
- * E-mail: (TLB); (LS)
| | - Joe Rayner
- SynthSys, The University of Edinburgh, Edinburgh, United Kingdom
- Centre for Science at Extreme Conditions, University of Edinburgh, Edinburgh, United Kingdom
| | - Marcia M. Roy
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Laura Spagnolo
- Institute of Structural and Molecular Biology, University of Edinburgh, Edinburgh, United Kingdom
- Centre for Science at Extreme Conditions, University of Edinburgh, Edinburgh, United Kingdom
- * E-mail: (TLB); (LS)
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7
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Pradel N, Ji B, Gimenez G, Talla E, Lenoble P, Garel M, Tamburini C, Fourquet P, Lebrun R, Bertin P, Denis Y, Pophillat M, Barbe V, Ollivier B, Dolla A. The first genomic and proteomic characterization of a deep-sea sulfate reducer: insights into the piezophilic lifestyle of Desulfovibrio piezophilus. PLoS One 2013; 8:e55130. [PMID: 23383081 PMCID: PMC3559428 DOI: 10.1371/journal.pone.0055130] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Accepted: 12/18/2012] [Indexed: 01/19/2023] Open
Abstract
Desulfovibrio piezophilus strain C1TLV30(T) is a piezophilic anaerobe that was isolated from wood falls in the Mediterranean deep-sea. D. piezophilus represents a unique model for studying the adaptation of sulfate-reducing bacteria to hydrostatic pressure. Here, we report the 3.6 Mbp genome sequence of this piezophilic bacterium. An analysis of the genome revealed the presence of seven genomic islands as well as gene clusters that are most likely linked to life at a high hydrostatic pressure. Comparative genomics and differential proteomics identified the transport of solutes and amino acids as well as amino acid metabolism as major cellular processes for the adaptation of this bacterium to hydrostatic pressure. In addition, the proteome profiles showed that the abundance of key enzymes that are involved in sulfate reduction was dependent on hydrostatic pressure. A comparative analysis of orthologs from the non-piezophilic marine bacterium D. salexigens and D. piezophilus identified aspartic acid, glutamic acid, lysine, asparagine, serine and tyrosine as the amino acids preferentially replaced by arginine, histidine, alanine and threonine in the piezophilic strain. This work reveals the adaptation strategies developed by a sulfate reducer to a deep-sea lifestyle.
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Affiliation(s)
- Nathalie Pradel
- Aix-Marseille Université, Université du Sud Toulon-Var, CNRS/INSU, IRD, MIO, UM110, Marseille, France
- * E-mail: (NP); (AD)
| | - Boyang Ji
- Aix-Marseille Université, CNRS, LCB, UMR 7283, Marseille, France
| | | | - Emmanuel Talla
- Aix-Marseille Université, CNRS, LCB, UMR 7283, Marseille, France
| | - Patricia Lenoble
- Laboratoire de Finition C.E.A., Institut de Génomique – Genoscope, Evry, France
| | - Marc Garel
- Aix-Marseille Université, Université du Sud Toulon-Var, CNRS/INSU, IRD, MIO, UM110, Marseille, France
| | - Christian Tamburini
- Aix-Marseille Université, Université du Sud Toulon-Var, CNRS/INSU, IRD, MIO, UM110, Marseille, France
| | | | - Régine Lebrun
- Plate-formes Protéomique et Transcriptomique FR3479, IBiSA Marseille-Protéomique. IMM - CNRS, Marseille, France
| | - Philippe Bertin
- UMR 7156, CNRS, Université Louis Pasteur, Strasbourg, France
| | - Yann Denis
- Plate-formes Protéomique et Transcriptomique FR3479, IBiSA Marseille-Protéomique. IMM - CNRS, Marseille, France
| | | | - Valérie Barbe
- Laboratoire de Finition C.E.A., Institut de Génomique – Genoscope, Evry, France
| | - Bernard Ollivier
- Aix-Marseille Université, Université du Sud Toulon-Var, CNRS/INSU, IRD, MIO, UM110, Marseille, France
| | - Alain Dolla
- Aix-Marseille Université, CNRS, LCB, UMR 7283, Marseille, France
- * E-mail: (NP); (AD)
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The respiratory system of the piezophile Photobacterium profundum SS9 grown under various pressures. Biosci Biotechnol Biochem 2012; 76:1506-10. [PMID: 22878211 DOI: 10.1271/bbb.120237] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
It is known that the facultative piezophile Shewanella violacea DSS12 alters its respiratory components under the influence of hydrostatic pressure during growth. This can be considered one of the mechanisms of bacterial adaptation to high pressure. In this study, we investigated the respiratory system of another well-studied piezophile, Photobacterium profundum SS9. We analyzed cytochrome contents, the expression of genes encoding respiratory components in P. profundum SS9 grown under various conditions, and the pressure dependency of the terminal oxidase activities. Activity was more tolerant of relatively high pressures, such as 125 MPa when the cells were grown under high pressure as compared with cells grown under atmospheric pressure. Such properties observed are similar to the case of S. violacea. However, the contents of the cytochromes and expression of the respiratory genes were not influenced by growth pressure in P. profundum SS9, inconsistent with the case of S. violacea. We suggest that the mechanism of the piezoadaptation of the respiratory system of P. profundum SS9 differs from that of S. violacea, as described above, and that each strain chooses its own strategy.
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Abstract
Marine macro- and micro-biota offer a wealth of chemically diverse compounds that have been evolutionary preselected to modulate biochemical pathways. Many industrial and academic groups are accessing this source using advanced technology platforms. The previous edition of this chapter offered some practical guidance in the process of extraction and isolation of marine natural products with more emphasis on the procedures adapted to the physical and chemical characteristics of the isolated compounds. Automation and direct integration of the isolation technology into high-throughput screening (HTS) systems were also reported. In this edition, we refer to some new topics which are heavily represented in the literature. These include methods for sampling the deep ocean and the procedures for culturing high-pressure-adapted (piezophilic) marine microorganisms to be amenable to laboratory investigation. A brief discussion on genomic-guided approaches to detect the presence of biosynthetic loci even those that are silent or cryptic is also included.
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Affiliation(s)
- Wael E Houssen
- Department of Chemistry, Marine Biodiscovery Centre, University of Aberdeen, Old Aberdeen, UK
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Rosenbaum E, Gabel F, Durá MA, Finet S, Cléry-Barraud C, Masson P, Franzetti B. Effects of hydrostatic pressure on the quaternary structure and enzymatic activity of a large peptidase complex from Pyrococcus horikoshii. Arch Biochem Biophys 2011; 517:104-10. [PMID: 21896270 DOI: 10.1016/j.abb.2011.07.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Accepted: 07/31/2011] [Indexed: 10/17/2022]
Abstract
While molecular adaptation to high temperature has been extensively studied, the effect of hydrostatic pressure on protein structure and enzymatic activity is still poorly understood. We have studied the influence of pressure on both the quaternary structure and enzymatic activity of the dodecameric TET3 peptidase from Pyrococcus horikoshii. Small angle X-ray scattering (SAXS) revealed a high robustness of the oligomer under high pressure of up to 300 MPa at 25°C as well as at 90°C. The enzymatic activity of TET3 was enhanced by pressure up to 180 MPa. From the pressure behavior of the different rate-constants we have determined the volume changes associated with substrate binding and catalysis. Based on these results we propose that a change in the rate-limiting step occurs around 180 MPa.
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Affiliation(s)
- Eva Rosenbaum
- Group Extremophiles and Large Molecular Assemblies (ELMA), CEA, Institut de Biologie Structurale, Grenoble, France
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