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Scott KM, Payne RR, Gahramanova A. Widespread dissolved inorganic carbon-modifying toolkits in genomes of autotrophic Bacteria and Archaea and how they are likely to bridge supply from the environment to demand by autotrophic pathways. Appl Environ Microbiol 2024; 90:e0155723. [PMID: 38299815 PMCID: PMC10880623 DOI: 10.1128/aem.01557-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2024] Open
Abstract
Using dissolved inorganic carbon (DIC) as a major carbon source, as autotrophs do, is complicated by the bedeviling nature of this substance. Autotrophs using the Calvin-Benson-Bassham cycle (CBB) are known to make use of a toolkit comprised of DIC transporters and carbonic anhydrase enzymes (CA) to facilitate DIC fixation. This minireview provides a brief overview of the current understanding of how toolkit function facilitates DIC fixation in Cyanobacteria and some Proteobacteria using the CBB and continues with a survey of the DIC toolkit gene presence in organisms using different versions of the CBB and other autotrophic pathways (reductive citric acid cycle, Wood-Ljungdahl pathway, hydroxypropionate bicycle, hydroxypropionate-hydroxybutyrate cycle, and dicarboxylate-hydroxybutyrate cycle). The potential function of toolkit gene products in these organisms is discussed in terms of CO2 and HCO3- supply from the environment and demand by the autotrophic pathway. The presence of DIC toolkit genes in autotrophic organisms beyond those using the CBB suggests the relevance of DIC metabolism to these organisms and provides a basis for better engineering of these organisms for industrial and agricultural purposes.
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Affiliation(s)
- Kathleen M. Scott
- Integrative Biology Department, University of South Florida, Tampa, Florida, USA
| | - Ren R. Payne
- Integrative Biology Department, University of South Florida, Tampa, Florida, USA
| | - Arin Gahramanova
- Integrative Biology Department, University of South Florida, Tampa, Florida, USA
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2
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Koendjbiharie JG, van Kranenburg R, Kengen SWM. The PEP-pyruvate-oxaloacetate node: variation at the heart of metabolism. FEMS Microbiol Rev 2021; 45:fuaa061. [PMID: 33289792 PMCID: PMC8100219 DOI: 10.1093/femsre/fuaa061] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 11/18/2020] [Indexed: 12/15/2022] Open
Abstract
At the junction between the glycolysis and the tricarboxylic acid cycle-as well as various other metabolic pathways-lies the phosphoenolpyruvate (PEP)-pyruvate-oxaloacetate node (PPO-node). These three metabolites form the core of a network involving at least eleven different types of enzymes, each with numerous subtypes. Obviously, no single organism maintains each of these eleven enzymes; instead, different organisms possess different subsets in their PPO-node, which results in a remarkable degree of variation, despite connecting such deeply conserved metabolic pathways as the glycolysis and the tricarboxylic acid cycle. The PPO-node enzymes play a crucial role in cellular energetics, with most of them involved in (de)phosphorylation of nucleotide phosphates, while those responsible for malate conversion are important redox enzymes. Variations in PPO-node therefore reflect the different energetic niches that organisms can occupy. In this review, we give an overview of the biochemistry of these eleven PPO-node enzymes. We attempt to highlight the variation that exists, both in PPO-node compositions, as well as in the roles that the enzymes can have within those different settings, through various recent discoveries in both bacteria and archaea that reveal deviations from canonical functions.
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Affiliation(s)
- Jeroen G Koendjbiharie
- Laboratory of Microbiology, Wageningen University, Stippeneng4, 6708 WE Wageningen, The Netherlands
| | - Richard van Kranenburg
- Laboratory of Microbiology, Wageningen University, Stippeneng4, 6708 WE Wageningen, The Netherlands
- Corbion, Arkelsedijk 46, 4206 AC Gorinchem, The Netherlands
| | - Servé W M Kengen
- Laboratory of Microbiology, Wageningen University, Stippeneng4, 6708 WE Wageningen, The Netherlands
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3
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Glucose Metabolism and Acetate Switch in Archaea: the Enzymes in Haloferax volcanii. J Bacteriol 2021; 203:JB.00690-20. [PMID: 33558390 DOI: 10.1128/jb.00690-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 01/28/2021] [Indexed: 12/19/2022] Open
Abstract
The halophilic archaeon Haloferax volcanii has been proposed to degrade glucose via the semiphosphorylative Entner-Doudoroff (spED) pathway. Following our previous studies on key enzymes of this pathway, we now focus on the characterization of enzymes involved in 3-phosphoglycerate conversion to pyruvate, in anaplerosis, and in acetyl coenzyme A (acetyl-CoA) formation from pyruvate. These enzymes include phosphoglycerate mutase, enolase, pyruvate kinase, phosphoenolpyruvate carboxylase, and pyruvate-ferredoxin oxidoreductase. The essential function of these enzymes were shown by transcript analyses and growth experiments with respective deletion mutants. Furthermore, we show that H. volcanii-during aerobic growth on glucose-excreted significant amounts of acetate, which was consumed in the stationary phase (acetate switch). The enzyme catalyzing the conversion of acetyl-CoA to acetate as part of the acetate overflow mechanism, an ADP-forming acetyl-CoA synthetase (ACD), was characterized. The functional involvement of ACD in acetate formation and of AMP-forming acetyl-CoA synthetases (ACSs) in activation of excreted acetate was proven by using respective deletion mutants. Together, the data provide a comprehensive analysis of enzymes of the spED pathway and of anaplerosis and report the first genetic evidence of the functional involvement of enzymes of the acetate switch in archaea.IMPORTANCE In this work, we provide a comprehensive analysis of glucose degradation via the semiphosphorylative Entner-Doudoroff pathway in the haloarchaeal model organism Haloferax volcanii The study includes transcriptional analyses, growth experiments with deletion mutants. and characterization of all enzymes involved in the conversion of 3-phosphoglycerate to acetyl coenzyme A (acetyl-CoA) and in anaplerosis. Phylogenetic analyses of several enzymes indicate various lateral gene transfer events from bacteria to haloarchaea. Furthermore, we analyzed the key players involved in the acetate switch, i.e., in the formation (overflow) and subsequent consumption of acetate during aerobic growth on glucose. Together, the data provide novel aspects of glucose degradation, anaplerosis, and acetate switch in H. volcanii and thus expand our understanding of the unusual sugar metabolism in archaea.
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Bischof LF, Haurat MF, Hoffmann L, Albersmeier A, Wolf J, Neu A, Pham TK, Albaum SP, Jakobi T, Schouten S, Neumann-Schaal M, Wright PC, Kalinowski J, Siebers B, Albers SV. Early Response of Sulfolobus acidocaldarius to Nutrient Limitation. Front Microbiol 2019; 9:3201. [PMID: 30687244 PMCID: PMC6335949 DOI: 10.3389/fmicb.2018.03201] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 12/10/2018] [Indexed: 01/13/2023] Open
Abstract
In natural environments microorganisms encounter extreme changes in temperature, pH, osmolarities and nutrient availability. The stress response of many bacterial species has been described in detail, however, knowledge in Archaea is limited. Here, we describe the cellular response triggered by nutrient limitation in the thermoacidophilic crenarchaeon Sulfolobus acidocaldarius. We measured changes in gene transcription and protein abundance upon nutrient depletion up to 4 h after initiation of nutrient depletion. Transcript levels of 1118 of 2223 protein coding genes and abundance of approximately 500 proteins with functions in almost all cellular processes were affected by nutrient depletion. Our study reveals a significant rerouting of the metabolism with respect to degradation of internal as well as extracellular-bound organic carbon and degradation of proteins. Moreover, changes in membrane lipid composition were observed in order to access alternative sources of energy and to maintain pH homeostasis. At transcript level, the cellular response to nutrient depletion in S. acidocaldarius seems to be controlled by the general transcription factors TFB2 and TFEβ. In addition, ribosome biogenesis is reduced, while an increased protein degradation is accompanied with a loss of protein quality control. This study provides first insights into the early cellular response of Sulfolobus to organic carbon and organic nitrogen depletion.
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Affiliation(s)
- Lisa F Bischof
- Molecular Biology of Archaea, Institute of Biology II, University of Freiburg, Freiburg, Germany.,Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, Freiburg, Germany
| | - M Florencia Haurat
- Molecular Biology of Archaea, Institute of Biology II, University of Freiburg, Freiburg, Germany
| | - Lena Hoffmann
- Molecular Biology of Archaea, Institute of Biology II, University of Freiburg, Freiburg, Germany
| | - Andreas Albersmeier
- Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
| | - Jacqueline Wolf
- Department of Bioinformatics and Biochemistry, Braunschweig University of Technology, Braunschweig, Germany
| | - Astrid Neu
- Molecular Enzyme Technology and Biochemistry (MEB), Biofilm Centre, Centre for Water and Environmental Research (CWE), University of Duisburg-Essen, Essen, Germany
| | - Trong Khoa Pham
- Department of Chemical and Biological Engineering, The University of Sheffield, Sheffield, United Kingdom
| | - Stefan P Albaum
- Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
| | - Tobias Jakobi
- Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
| | - Stefan Schouten
- Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute of Sea Research, Den Burg, Netherlands.,Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, Netherlands
| | - Meina Neumann-Schaal
- Department of Bioinformatics and Biochemistry, Braunschweig University of Technology, Braunschweig, Germany
| | - Phillip C Wright
- Department of Chemical and Biological Engineering, The University of Sheffield, Sheffield, United Kingdom
| | - Jörn Kalinowski
- Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
| | - Bettina Siebers
- Molecular Enzyme Technology and Biochemistry (MEB), Biofilm Centre, Centre for Water and Environmental Research (CWE), University of Duisburg-Essen, Essen, Germany
| | - Sonja-Verena Albers
- Molecular Biology of Archaea, Institute of Biology II, University of Freiburg, Freiburg, Germany
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Kao PH, Ng IS. CRISPRi mediated phosphoenolpyruvate carboxylase regulation to enhance the production of lipid in Chlamydomonas reinhardtii. BIORESOURCE TECHNOLOGY 2017; 245:1527-1537. [PMID: 28501380 DOI: 10.1016/j.biortech.2017.04.111] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 04/26/2017] [Accepted: 04/28/2017] [Indexed: 05/02/2023]
Abstract
In this study, CRISPRi (clustered regularly interspaced short palindromic repeats interference) was used for the first time to regulate expression of exogenously supplied rfp gene as a proof-of-concept, and endogenous PEPC1 gene as a proof-of-function in Chlamydomonas reinhardtii. The efficiency of 94% and stability of 7 generations via CRISPRi mediated gene regulation in C. reinhardtii have been demonstrated by RFP. Gene PEPC1 encoding proteins are essential for controlling the carbon flux that enters the TCA cycle and plays a crucial role in carbon partitioning of substrates in competition with lipid synthesis. All CrPEPC1 down-regulated strains have lower chlorophyll color, but higher biomass concentration and lipid accumulation rate. The present results revealed that CRISPRi based transcriptional silencing was applicable in C. reinhardtii and expanded the way to improve the yield, titer and productivity of microalgae-based products.
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Affiliation(s)
- Pei-Hsun Kao
- Department of Chemical Engineering, National Cheng Kung University, Tainan 70101, Taiwan
| | - I-Son Ng
- Department of Chemical Engineering, National Cheng Kung University, Tainan 70101, Taiwan; Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan 70101, Taiwan.
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6
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He Y, Li M, Perumal V, Feng X, Fang J, Xie J, Sievert SM, Wang F. Genomic and enzymatic evidence for acetogenesis among multiple lineages of the archaeal phylum Bathyarchaeota widespread in marine sediments. Nat Microbiol 2016; 1:16035. [PMID: 27572832 DOI: 10.1038/nmicrobiol.2016.35] [Citation(s) in RCA: 178] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 02/24/2016] [Indexed: 01/13/2023]
Abstract
Members of the archaeal phylum Bathyarchaeota are widespread and abundant in the energy-deficient marine subsurface sediments. However, their life strategies have remained largely elusive. Here, we provide genetic evidence that some lineages of Bathyarchaeota are acetogens, being capable of homoacetogenesis, a metabolism so far restricted to the domain Bacteria. Metabolic reconstruction based on genomic bins assembled from the metagenome of deep-sea subsurface sediments shows that the metabolism of some lineages of Bathyarchaeota is similar to that of bona fide bacterial homoacetogens, by having pathways for acetogenesis and for the fermentative utilization of a variety of organic substrates. Heterologous expression and activity assay of the acetate kinase gene ack from Bathyarchaeota, demonstrate further the capability of these Bathyarchaeota to grow as acetogens. The presence and expression of bathyarchaeotal genes indicative of active acetogenesis was also confirmed in Peru Margin subsurface sediments where Bathyarchaeota are abundant. The analyses reveal that this ubiquitous and abundant subsurface archaeal group has adopted a versatile life strategy to make a living under energy-limiting conditions. These findings further expand the metabolic potential of Archaea and argue for a revision of the role of Archaea in the carbon cycle of marine sediments.
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Affiliation(s)
- Y He
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.,State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - M Li
- Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong, China
| | - V Perumal
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - X Feng
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - J Fang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - J Xie
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - S M Sievert
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA
| | - F Wang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.,State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University, Shanghai, China
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Expression and knockdown of the PEPC1 gene affect carbon flux in the biosynthesis of triacylglycerols by the green alga Chlamydomonas reinhardtii. Biotechnol Lett 2014; 36:2199-208. [PMID: 24966045 DOI: 10.1007/s10529-014-1593-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 06/12/2014] [Indexed: 12/22/2022]
Abstract
The regulation of lipid biosynthesis is important in photosynthetic eukaryotic cells. This regulation is facilitated by the direct synthesis of fatty acids and triacylglycerol (TAG), and by other controls of the main carbon metabolic pathway. In this study, knockdown of the mRNA expression of the Chlamydomonas phosphoenolpyruvate carboxylase isoform 1 (CrPEPC1) gene by RNA interference increased TAG level by 20 % but decreased PEPC activities in the corresponding transgenic algae by 39-50 %. The decrease in CrPEPC1 expression increased the expression of TAG biosynthesis-related genes, such as acyl-CoA:diacylglycerol acyltransferase and phosphatidate phosphatase. Conversely, CrPEPC1 over-expression decreased TAG level by 37 % and increased PEPC activities by 157-184 %. These observations suggest that the lipid content of algal cells can be controlled by regulating the CrPEPC1 gene.
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9
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The remarkable diversity of plant PEPC (phosphoenolpyruvate carboxylase): recent insights into the physiological functions and post-translational controls of non-photosynthetic PEPCs. Biochem J 2011; 436:15-34. [DOI: 10.1042/bj20110078] [Citation(s) in RCA: 224] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PEPC [PEP (phosphoenolpyruvate) carboxylase] is a tightly controlled enzyme located at the core of plant C-metabolism that catalyses the irreversible β-carboxylation of PEP to form oxaloacetate and Pi. The critical role of PEPC in assimilating atmospheric CO2 during C4 and Crassulacean acid metabolism photosynthesis has been studied extensively. PEPC also fulfils a broad spectrum of non-photosynthetic functions, particularly the anaplerotic replenishment of tricarboxylic acid cycle intermediates consumed during biosynthesis and nitrogen assimilation. An impressive array of strategies has evolved to co-ordinate in vivo PEPC activity with cellular demands for C4–C6 carboxylic acids. To achieve its diverse roles and complex regulation, PEPC belongs to a small multigene family encoding several closely related PTPCs (plant-type PEPCs), along with a distantly related BTPC (bacterial-type PEPC). PTPC genes encode ~110-kDa polypeptides containing conserved serine-phosphorylation and lysine-mono-ubiquitination sites, and typically exist as homotetrameric Class-1 PEPCs. In contrast, BTPC genes encode larger ~117-kDa polypeptides owing to a unique intrinsically disordered domain that mediates BTPC's tight interaction with co-expressed PTPC subunits. This association results in the formation of unusual ~900-kDa Class-2 PEPC hetero-octameric complexes that are desensitized to allosteric effectors. BTPC is a catalytic and regulatory subunit of Class-2 PEPC that is subject to multi-site regulatory phosphorylation in vivo. The interaction between divergent PEPC polypeptides within Class-2 PEPCs adds another layer of complexity to the evolution, physiological functions and metabolic control of this essential CO2-fixing plant enzyme. The present review summarizes exciting developments concerning the functions, post-translational controls and subcellular location of plant PTPC and BTPC isoenzymes.
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Dharmarajan L, Kraszewski JL, Mukhopadhyay B, Dunten PW. Structure of an archaeal-type phosphoenolpyruvate carboxylase sensitive to inhibition by aspartate. Proteins 2011; 79:1820-9. [PMID: 21491491 DOI: 10.1002/prot.23006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Revised: 01/06/2011] [Accepted: 01/21/2011] [Indexed: 11/06/2022]
Abstract
The crystal structure of an archaeal-type phosphoenolpyruvate carboxylase from Clostridium perfringens has been determined based on X-ray data extending to 3 Å. The asymmetric unit of the structure includes two tetramers (each a dimer-of-dimers) of the enzyme. The precipitant, malonate, employed for the crystallization is itself a weak inhibitor of phosphoenolpyruvate carboxylase and a malonate molecule is seen in the active-site in the crystal structure. The allosteric binding sites for aspartate (an inhibitor) and glucose-6-phosphate (an activator) observed in the Escherichia coli and Zea mays phosphoenolpyruvate carboxylase structures, respectively, are not conserved in the C. perfringens structure. Aspartate inhibits the C. perfringens enzyme competitively with respect to the substrate, Mg(++.) phosphoenolpyruvate. A mechanism for inhibition is proposed based on the structure and sequence comparisons with other archaeal-type phosphoenolpyruvate carboxylases with differing sensitivity to inhibition by aspartate.
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Affiliation(s)
- Lakshmi Dharmarajan
- Virginia Bioinformatics Institute, Bioinformatics and Computational Biology Graduate Program, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA
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Černý M, Doubnerová V, Müller K, Ryšlavá H. Characterization of phosphoenolpyruvate carboxylase from mature maize seeds: Properties of phosphorylated and dephosphorylated forms. Biochimie 2010; 92:1362-70. [DOI: 10.1016/j.biochi.2010.06.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Accepted: 06/18/2010] [Indexed: 10/19/2022]
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12
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Berg IA, Kockelkorn D, Ramos-Vera WH, Say RF, Zarzycki J, Hügler M, Alber BE, Fuchs G. Autotrophic carbon fixation in archaea. Nat Rev Microbiol 2010; 8:447-60. [DOI: 10.1038/nrmicro2365] [Citation(s) in RCA: 467] [Impact Index Per Article: 33.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Dharmarajan L, Kraszewski JL, Mukhopadhyay B, Dunten PW. Expression, purification and crystallization of an archaeal-type phosphoenolpyruvate carboxylase. Acta Crystallogr Sect F Struct Biol Cryst Commun 2009; 65:1193-6. [PMID: 19923749 DOI: 10.1107/s1744309109042663] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2009] [Accepted: 10/16/2009] [Indexed: 11/10/2022]
Abstract
An archaeal-type phosphoenolpyruvate carboxylase (PepcA) from Clostridium perfringens has been expressed in Escherichia coli in a soluble form with an amino-terminal His tag. The recombinant protein is enzymatically active and two crystal forms have been obtained. Complete diffraction data extending to 3.13 angstrom resolution have been measured from a crystal soaked in KAu(CN)(2), using radiation at a wavelength just above the Au L(III) edge. The asymmetric unit contains two tetramers of PepcA.
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Podar M, Anderson I, Makarova KS, Elkins JG, Ivanova N, Wall MA, Lykidis A, Mavromatis K, Sun H, Hudson ME, Chen W, Deciu C, Hutchison D, Eads JR, Anderson A, Fernandes F, Szeto E, Lapidus A, Kyrpides NC, Saier MH, Richardson PM, Rachel R, Huber H, Eisen JA, Koonin EV, Keller M, Stetter KO. A genomic analysis of the archaeal system Ignicoccus hospitalis-Nanoarchaeum equitans. Genome Biol 2008; 9:R158. [PMID: 19000309 PMCID: PMC2614490 DOI: 10.1186/gb-2008-9-11-r158] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2008] [Revised: 10/21/2008] [Accepted: 11/10/2008] [Indexed: 01/03/2023] Open
Abstract
Sequencing of the complete genome of Ignicoccus hospitalis gives insight into its association with another species of Archaea, Nanoarchaeum equitans. Background The relationship between the hyperthermophiles Ignicoccus hospitalis and Nanoarchaeum equitans is the only known example of a specific association between two species of Archaea. Little is known about the mechanisms that enable this relationship. Results We sequenced the complete genome of I. hospitalis and found it to be the smallest among independent, free-living organisms. A comparative genomic reconstruction suggests that the I. hospitalis lineage has lost most of the genes associated with a heterotrophic metabolism that is characteristic of most of the Crenarchaeota. A streamlined genome is also suggested by a low frequency of paralogs and fragmentation of many operons. However, this process appears to be partially balanced by lateral gene transfer from archaeal and bacterial sources. Conclusions A combination of genomic and cellular features suggests highly efficient adaptation to the low energy yield of sulfur-hydrogen respiration and efficient inorganic carbon and nitrogen assimilation. Evidence of lateral gene exchange between N. equitans and I. hospitalis indicates that the relationship has impacted both genomes. This association is the simplest symbiotic system known to date and a unique model for studying mechanisms of interspecific relationships at the genomic and metabolic levels.
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Affiliation(s)
- Mircea Podar
- Biosciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN 37831, USA.
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15
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Klimke W, Agarwala R, Badretdin A, Chetvernin S, Ciufo S, Fedorov B, Kiryutin B, O'Neill K, Resch W, Resenchuk S, Schafer S, Tolstoy I, Tatusova T. The National Center for Biotechnology Information's Protein Clusters Database. Nucleic Acids Res 2008; 37:D216-23. [PMID: 18940865 PMCID: PMC2686591 DOI: 10.1093/nar/gkn734] [Citation(s) in RCA: 219] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Rapid increases in DNA sequencing capabilities have led to a vast increase in the data generated from prokaryotic genomic studies, which has been a boon to scientists studying micro-organism evolution and to those who wish to understand the biological underpinnings of microbial systems. The NCBI Protein Clusters Database (ProtClustDB) has been created to efficiently maintain and keep the deluge of data up to date. ProtClustDB contains both curated and uncurated clusters of proteins grouped by sequence similarity. The May 2008 release contains a total of 285 386 clusters derived from over 1.7 million proteins encoded by 3806 nt sequences from the RefSeq collection of complete chromosomes and plasmids from four major groups: prokaryotes, bacteriophages and the mitochondrial and chloroplast organelles. There are 7180 clusters containing 376 513 proteins with curated gene and protein functional annotation. PubMed identifiers and external cross references are collected for all clusters and provide additional information resources. A suite of web tools is available to explore more detailed information, such as multiple alignments, phylogenetic trees and genomic neighborhoods. ProtClustDB provides an efficient method to aggregate gene and protein annotation for researchers and is available at http://www.ncbi.nlm.nih.gov/sites/entrez?db=proteinclusters.
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Affiliation(s)
- William Klimke
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Department of Health and Human Services, Building 38A, 8600 Rockville Pike, Bethesda, MD 20894, USA.
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16
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Moellering ER, Ouyang Y, Mamedov TG, Chollet R. The two divergent PEP-carboxylase catalytic subunits in the green microalga Chlamydomonas reinhardtii respond reversibly to inorganic-N supply and co-exist in the high-molecular-mass, hetero-oligomeric Class-2 PEPC complex. FEBS Lett 2007; 581:4871-6. [PMID: 17888908 DOI: 10.1016/j.febslet.2007.09.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2007] [Revised: 09/07/2007] [Accepted: 09/08/2007] [Indexed: 10/22/2022]
Abstract
Our recent molecular studies revealed two divergent PEP-carboxylase (PEPC [Ppc]) encoding genes in the green microalga Chlamydomonas reinhardtii, CrPpc1 and CrPpc2, which are coordinately responsive to changes in inorganic-N and -C supply at the transcript level [Mamedov, T.G., Moellering, E.R. and Chollet, R. (2005) Identification and expression analysis of two inorganic C- and N-responsive genes encoding novel and distinct molecular forms of eukaryotic phosphoenolpyruvate carboxylase in the green microalga C. reinhardtii, Plant J. 42, 832-843]. Here, we report the distribution of these two encoded catalytic subunits in the minor Class-1 and predominant Class-2 PEPC enzyme-forms, the latter of which is a novel high-molecular-mass, hetero-oligomeric complex containing both CrPpc1 (p109) and CrPpc2 (p131) polypeptides. The Class-1 enzyme, however, is a typical PEPC homotetramer comprised solely of p109. We also document that the amount of both CrPpc1/2 catalytic subunits is up-/down-regulated by varying levels of NH(4)(+) supplied to the culture medium.
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Affiliation(s)
- Eric R Moellering
- Department of Biochemistry, University of Nebraska-Lincoln, George W. Beadle Center, Lincoln, NE 68588-0664, USA
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Hu Y, Holden JF. Citric acid cycle in the hyperthermophilic archaeon Pyrobaculum islandicum grown autotrophically, heterotrophically, and mixotrophically with acetate. J Bacteriol 2006; 188:4350-5. [PMID: 16740941 PMCID: PMC1482950 DOI: 10.1128/jb.00138-06] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The hyperthermophilic archaeon Pyrobaculum islandicum uses the citric acid cycle in the oxidative and reductive directions for heterotrophic and autotrophic growth, respectively, but the control of carbon flow is poorly understood. P. islandicum was grown at 95 degrees C autotrophically, heterotrophically, and mixotrophically with acetate, H2, and small amounts of yeast extract and with thiosulfate as the terminal electron acceptor. The autotrophic growth rates and maximum concentrations of cells were significantly lower than those in other media. The growth rates on H2 and 0.001% yeast extract with and without 0.05% acetate were the same, but the maximum concentration of cells was fourfold higher with acetate. There was no growth with acetate if 0.001% yeast extract was not present, and addition of H2 to acetate-containing medium greatly increased the growth rates and maximum concentrations of cells. P. islandicum cultures assimilated 14C-labeled acetate in the presence of H2 and yeast extract with an efficiency of 55%. The activities of 11 of 19 enzymes involved in the central metabolism of P. islandicum were regulated under the three different growth conditions. Pyruvate synthase and acetate:coenzyme A (CoA) ligase (ADP-forming) activities were detected only in heterotrophically grown cultures. Citrate synthase activity decreased in autotrophic and acetate-containing cultures compared to the activity in heterotrophic cultures. Acetylated citrate lyase, acetate:CoA ligase (AMP forming), and phosphoenolpyruvate carboxylase activities increased in autotrophic and acetate-containing cultures. Citrate lyase activity was higher than ATP citrate synthase activity in autotrophic cultures. These data suggest that citrate lyase and AMP-forming acetate:CoA ligase, but not ATP citrate synthase, work opposite citrate synthase to control the direction of carbon flow in the citric acid cycle.
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Affiliation(s)
- Yajing Hu
- Department of Microbiology, University of Massachusetts, Amherst, MA 01003, USA
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Matsumura H, Izui K, Mizuguchi K. A novel mechanism of allosteric regulation of archaeal phosphoenolpyruvate carboxylase: a combined approach to structure-based alignment and model assessment. Protein Eng Des Sel 2006; 19:409-19. [PMID: 16815866 DOI: 10.1093/protein/gzl025] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Phosphoenolpyruvate carboxylase (PEPC) catalyzes the irreversible carboxylation of phosphoenolpyruvate (PEP) and plays a crucial role in fixing atmospheric CO(2) in C(4) and CAM plants. The enzyme is widespread in plants and bacteria and mostly regulated allosterically by both positive and negative effectors. Archaeal PEPCs (A-PEPCs) have unique characteristics in allosteric regulation and molecular mass, distinct from their bacterial and eukaryote homologues, and their amino acid sequences have become available only recently. In this paper, we generated a structure-based alignment of archaeal, bacterial and eukaryote PEPCs and built comparative models using a combination of fold recognition, sequence and structural analysis tools. Our comparative modeling analysis identified A-PEPC-specific strong interactions between the two loops involved in both allostery and catalysis, which explained why A-PEPC is not influenced by any allosteric activators. We also found that the side-chain located three residues before the C-terminus appears to play a key role in determining the sensitivity to allosteric inhibitors. In addition to these unique features, we revealed how archaeal, bacterial and eukaryote PEPCs would share a common catalytic mechanism and adopt a similar mode of tetramer formation, despite their divergent sequences. Our novel observations will help design more efficient molecules for ecological and industrial use.
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19
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Tjaden B, Plagens A, Dörr C, Siebers B, Hensel R. Phosphoenolpyruvate synthetase and pyruvate, phosphate dikinase of Thermoproteus tenax: key pieces in the puzzle of archaeal carbohydrate metabolism. Mol Microbiol 2006; 60:287-98. [PMID: 16573681 DOI: 10.1111/j.1365-2958.2006.05098.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The interconversion of phosphoenolpyruvate and pyruvate represents an important control point of the Embden-Meyerhof-Parnas (EMP) pathway in Bacteria and Eucarya, but little is known about this site of regulation in Archaea. Here we report on the coexistence of phosphoenolpyruvate synthetase (PEPS) and the first described archaeal pyruvate, phosphate dikinase (PPDK), which, besides pyruvate kinase (PK), are involved in the catalysis of this reaction in the hyperthermophilic crenarchaeote Thermoproteus tenax. The genes encoding T. tenax PEPS and PPDK were cloned and expressed in Escherichia coli, and the enzymic and regulatory properties of the recombinant gene products were analysed. Whereas PEPS catalyses the unidirectional conversion of pyruvate to phosphoenolpyruvate, PPDK shows a bidirectional activity with a preference for the catabolic reaction. In contrast to PK of T. tenax, which is regulated on transcript level but exhibits only limited regulatory potential on protein level, PEPS and PPDK activities are modulated by adenosine phosphates and intermediates of the carbohydrate metabolism. Additionally, expression of PEPS is regulated on transcript level in response to the offered carbon source as revealed by Northern blot analyses. The combined action of the differently regulated enzymes PEPS, PPDK and PK represents a novel way of controlling the interconversion of phosphoenolpyruvate and pyruvate in the reversible EMP pathway, allowing short-term and long-term adaptation to different trophic conditions. Comparative genomic analyses indicate the coexistence of PEPS, PPDK and PK in other Archaea as well, suggesting a similar regulation of the carbohydrate metabolism in these organisms.
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Affiliation(s)
- Britta Tjaden
- Department of Microbiology, Universität Duisburg-Essen, 45117 Essen, Germany.
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20
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Golyshina OV, Golyshin PN, Timmis KN, Ferrer M. The 'pH optimum anomaly' of intracellular enzymes of Ferroplasma acidiphilum. Environ Microbiol 2006; 8:416-25. [PMID: 16478448 DOI: 10.1111/j.1462-2920.2005.00907.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A wide range of microorganisms, the so-called acidophiles, inhabit acidic environments and grow optimally at pH values between 0 and 3. The intracellular pH of these organisms is, however, close to neutrality or slightly acidic. It is to be expected that enzymatic activities dedicated to extracellular functions would be adapted to the prevailing low pH of the environment (0-3), whereas intracellular enzymes would be optimally active at the near-neutral pH of the cytoplasm (4.6-7.0). The genes of several intracellular or cell-bound enzymes, a carboxylesterase and three alpha-glucosidases, from Ferroplasma acidiphilum, a cell wall-lacking acidophilic archaeon with a growth optimum at pH 1.7, were cloned and expressed in Escherichia coli, and their products purified and characterized. The Ferroplasmaalpha-glucosidases exhibited no sequence similarity to known glycosyl hydrolases. All enzymes functioned and were stable in vitro in the pH range 1.7-4.0, and had pH optima much lower than the mean intracellular pH of 5.6. This 'pH optimum anomaly' suggests the existence of yet-undetected cellular compartmentalization providing cytoplasmic pH patchiness and low pH environments for the enzymes we have analysed.
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Affiliation(s)
- Olga V Golyshina
- Division of Microbiology, GBF--German Research Centre for Biotechnology, Braunschweig, Germany
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21
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Snijders APL, Walther J, Peter S, Kinnman I, de Vos MGJ, van de Werken HJG, Brouns SJJ, van der Oost J, Wright PC. Reconstruction of central carbon metabolism inSulfolobus solfataricus using a two-dimensional gel electrophoresis map, stable isotope labelling and DNA microarray analysis. Proteomics 2006; 6:1518-29. [PMID: 16447154 DOI: 10.1002/pmic.200402070] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In the last decade, an increasing number of sequenced archaeal genomes have become available, opening up the possibility for functional genomic analyses. Here, we reconstructed the central carbon metabolism in the hyperthermophilic crenarchaeon Sulfolobus solfataricus (glycolysis, gluconeogenesis and tricarboxylic acid cycle) on the basis of genomic, proteomic, transcriptomic and biochemical data. A 2-DE reference map of S. solfataricus grown on glucose, consisting of 325 unique ORFs in 255 protein spots, was created to facilitate this study. The map was then used for a differential expression study based on (15)N metabolic labelling (yeast extract + tryptone-grown cells (YT) vs. glucose-grown cells (G)). In addition, the expression ratio of the genes involved in carbon metabolism was studied using DNA microarrays. Surprisingly, only 3 and 14% of the genes and proteins, respectively, involved in central carbon metabolism showed a greater than two-fold change in expression level. All results are discussed in the light of the current understanding of central carbon metabolism in S. solfataricus and will help to obtain a system-wide understanding of this organism.
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Affiliation(s)
- Ambrosius P L Snijders
- Biological and Environmental Systems Group, Department of Chemical and Process Engineering, University of Sheffield, Sheffield, UK
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22
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Makarova KS, Koonin EV. Evolutionary and functional genomics of the Archaea. Curr Opin Microbiol 2005; 8:586-94. [PMID: 16111915 DOI: 10.1016/j.mib.2005.08.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2005] [Accepted: 08/05/2005] [Indexed: 11/20/2022]
Abstract
In the past two years, archaeal genomics has achieved several breakthroughs. On the evolutionary front the most exciting development was the sequencing and analysis of the genome of Nanoarchaeum equitans, a tiny parasitic organism that has only approximately 540 genes. The genome of Nanoarchaeum shows signs of extreme rearrangement including the virtual absence of conserved operons and the presence of several split genes. Nanoarchaeum is distantly related to other archaea, and it has been proposed to represent a deep archaeal branch that is distinct from Euryarchaeota and Crenarchaeota. This would imply that many features of its gene repertoire and genome organization might be ancestral. However, additional genome analysis has provided a more conservative suggestion - that Nanoarchaeum is a highly derived euryarchaeon. Also there have been substantial developments in functional genomics, including the discovery of the elusive aminoacyl-tRNA synthetase that is involved in both the biosynthesis of cysteine and its incorporation into proteins in methanogens, and the first experimental validation of the predicted archaeal exosome.
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Affiliation(s)
- Kira S Makarova
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
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23
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Ettema TJG, de Vos WM, van der Oost J. Discovering novel biology by in silico archaeology. Nat Rev Microbiol 2005; 3:859-69. [PMID: 16175172 DOI: 10.1038/nrmicro1268] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Archaea are prokaryotes that evolved in parallel with bacteria. Since the discovery of the distinct status of the Archaea, extensive physiological and biochemical research has been conducted to elucidate the molecular basis of their remarkable lifestyle and their unique biology. Here, we discuss how in-depth comparative genomics has been used to improve the annotation of archaeal genomes. Combined with experimental verification, bioinformatic analysis contributes to the ongoing discovery of novel metabolic conversions and control mechanisms, and as such to a better understanding of the intriguing biology of the Archaea.
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Affiliation(s)
- Thijs J G Ettema
- Laboratory of Microbiology, Wageningen University, 6703 CT Wageningen, The Netherlands
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Mamedov TG, Moellering ER, Chollet R. Identification and expression analysis of two inorganic C- and N-responsive genes encoding novel and distinct molecular forms of eukaryotic phosphoenolpyruvate carboxylase in the green microalga Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2005; 42:832-43. [PMID: 15941397 DOI: 10.1111/j.1365-313x.2005.02416.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Phosphoenolpyruvate carboxylase (PEPC [Ppc]) has been previously purified and characterized in biochemical and immunological terms from two green microalgae, Chlamydomonas reinhardtii and Selenastrum minutum. The findings indicate that these algae possess at least two distinct PEPC enzyme-forms, homotetrameric Class-1 and heteromeric Class-2, that differ significantly from each other and their plant and prokaryotic counterparts. Surprisingly, however, green-algal PEPC has been unexplored to date in molecular terms. This study reports the molecular cloning of the two Ppc genes in C. reinhardtii (CrPpc1, CrPpc2), each of which is transcribed in vivo and encodes a fully active, recombinant PEPC that lacks the regulatory, N-terminal seryl-phosphorylation domain that typifies the vascular-plant enzyme. These distinct catalytic subunit-types differ with respect to their (i) predicted molecular mass ( approximately 108.9 [CrPpc1] versus approximately 131.2 kDa [CrPpc2]) and critical C-terminal tetrapeptide; and (ii) immunoreactivity with antisera against the p102 and p130 polypeptides of S. minutum PEPC1/PEPC2 and PEPC2, respectively. Only the Ppc1 transcript encodes the p102 catalytic subunits common to both Class-1 and Class-2 enzyme-forms in C. reinhardtii. The steady-state transcript levels of both CrPpc1/2 are coordinately up-/down-regulated by changes in [CO2] or [NH] during growth, and generally mirror the response of cytoplasmic glutamine synthetase (Gs1) transcript abundance to changes in inorganic [N] at 5% CO2. These collective findings provide key molecular insight into the Ppc genes and corresponding PEPC catalytic subunits in the eukaryotic algae.
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Affiliation(s)
- Tarlan G Mamedov
- Department of Biochemistry, University of Nebraska-Lincoln, George W. Beadle Center, Lincoln, NE 68588-0664, USA
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25
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Fukui T, Atomi H, Kanai T, Matsumi R, Fujiwara S, Imanaka T. Complete genome sequence of the hyperthermophilic archaeon Thermococcus kodakaraensis KOD1 and comparison with Pyrococcus genomes. Genome Res 2005; 15:352-63. [PMID: 15710748 PMCID: PMC551561 DOI: 10.1101/gr.3003105] [Citation(s) in RCA: 357] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2004] [Accepted: 12/21/2004] [Indexed: 01/27/2023]
Abstract
The genus Thermococcus, comprised of sulfur-reducing hyperthermophilic archaea, belongs to the order Thermococcales in Euryarchaeota along with the closely related genus Pyrococcus. The members of Thermococcus are ubiquitously present in natural high-temperature environments, and are therefore considered to play a major role in the ecology and metabolic activity of microbial consortia within hot-water ecosystems. To obtain insight into this important genus, we have determined and annotated the complete 2,088,737-base genome of Thermococcus kodakaraensis strain KOD1, followed by a comparison with the three complete genomes of Pyrococcus spp. A total of 2306 coding DNA sequences (CDSs) have been identified, among which half (1165 CDSs) are annotatable, whereas the functions of 41% (936 CDSs) cannot be predicted from the primary structures. The genome contains seven genes for probable transposases and four virus-related regions. Several proteins within these genetic elements show high similarities to those in Pyrococcus spp., implying the natural occurrence of horizontal gene transfer of such mobile elements among the order Thermococcales. Comparative genomics clarified that 1204 proteins, including those for information processing and basic metabolisms, are shared among T. kodakaraensis and the three Pyrococcus spp. On the other hand, among the set of 689 proteins unique to T. kodakaraensis, there are several intriguing proteins that might be responsible for the specific trait of the genus Thermococcus, such as proteins involved in additional pyruvate oxidation, nucleotide metabolisms, unique or additional metal ion transporters, improved stress response system, and a distinct restriction system.
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Affiliation(s)
- Toshiaki Fukui
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
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Huynen MA, Gabaldón T, Snel B. Variation and evolution of biomolecular systems: Searching for functional relevance. FEBS Lett 2005; 579:1839-45. [PMID: 15763561 DOI: 10.1016/j.febslet.2005.02.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2005] [Revised: 01/18/2005] [Accepted: 02/01/2005] [Indexed: 11/29/2022]
Abstract
The availability of genome sequences and functional genomics data from multiple species enables us to compare the composition of biomolecular systems like biochemical pathways and protein complexes between species. Here, we review small- and large-scale, "genomics-based" approaches to biomolecular systems variation. In general, caution is required when comparing the results of bioinformatics analyses of genomes or of functional genomics data between species. Limitations to the sensitivity of sequence analysis tools and the noisy nature of genomics data tend to lead to systematic overestimates of the amount of variation. Nevertheless, the results from detailed manual analyses, and of large-scale analyses that filter out systematic biases, point to a large amount of variation in the composition of biomolecular systems. Such observations challenge our understanding of the function of the systems and their individual components and can potentially facilitate the identification and functional characterization of sub-systems within a system. Mapping the inter-species variation of complex biomolecular systems on a phylogenetic species tree allows one to reconstruct their evolution.
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Affiliation(s)
- Martijn A Huynen
- Center for Molecular and Biomolecular Informatics, Nijmegen Center for Molecular Life Sciences, Radboud University Nijmegen Medical Center, P.O. Box 9010, 6500 GL Nijmegen, The Netherlands.
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