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Moorefield J, Konuk Y, Norman JO, Abendroth J, Edwards TE, Lorimer DD, Mayclin SJ, Staker BL, Craig JK, Barett KF, Barrett LK, Van Voorhis WC, Myler PJ, McLaughlin KJ. Characterization of a family I inorganic pyrophosphatase from Legionella pneumophila Philadelphia 1. Acta Crystallogr F Struct Biol Commun 2023; 79:257-266. [PMID: 37728609 PMCID: PMC10565794 DOI: 10.1107/s2053230x23008002] [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] [Received: 07/11/2023] [Accepted: 09/13/2023] [Indexed: 09/21/2023] Open
Abstract
Inorganic pyrophosphate (PPi) is generated as an intermediate or byproduct of many fundamental metabolic pathways, including DNA/RNA synthesis. The intracellular concentration of PPi must be regulated as buildup can inhibit many critical cellular processes. Inorganic pyrophosphatases (PPases) hydrolyze PPi into two orthophosphates (Pi), preventing the toxic accumulation of the PPi byproduct in cells and making Pi available for use in biosynthetic pathways. Here, the crystal structure of a family I inorganic pyrophosphatase from Legionella pneumophila is reported at 2.0 Å resolution. L. pneumophila PPase (LpPPase) adopts a homohexameric assembly and shares the oligonucleotide/oligosaccharide-binding (OB) β-barrel core fold common to many other bacterial family I PPases. LpPPase demonstrated hydrolytic activity against a general substrate, with Mg2+ being the preferred metal cofactor for catalysis. Legionnaires' disease is a severe respiratory infection caused primarily by L. pneumophila, and thus increased characterization of the L. pneumophila proteome is of interest.
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Affiliation(s)
- Julia Moorefield
- Department of Chemistry, Vassar College, 124 Raymond Avenue, Poughkeepsie, NY 12604, USA
| | - Yagmur Konuk
- Department of Chemistry, Vassar College, 124 Raymond Avenue, Poughkeepsie, NY 12604, USA
| | - Jordan O. Norman
- Department of Chemistry, Vassar College, 124 Raymond Avenue, Poughkeepsie, NY 12604, USA
| | - Jan Abendroth
- Seattle Structural Genomics Center for Infectious Disease (SSGCID), Seattle, Washington, USA
- UCB Biosciences, 7869 Day Road West, Bainbridge Island, WA 98110, USA
| | - Thomas E. Edwards
- Seattle Structural Genomics Center for Infectious Disease (SSGCID), Seattle, Washington, USA
- UCB Biosciences, 7869 Day Road West, Bainbridge Island, WA 98110, USA
| | - Donald D. Lorimer
- Seattle Structural Genomics Center for Infectious Disease (SSGCID), Seattle, Washington, USA
- UCB Biosciences, 7869 Day Road West, Bainbridge Island, WA 98110, USA
| | - Stephen J. Mayclin
- Seattle Structural Genomics Center for Infectious Disease (SSGCID), Seattle, Washington, USA
- UCB Biosciences, 7869 Day Road West, Bainbridge Island, WA 98110, USA
| | - Bart L. Staker
- Seattle Structural Genomics Center for Infectious Disease (SSGCID), Seattle, Washington, USA
- Seattle Children’s Research Institute, University of Washington, Seattle, Washington, USA
| | - Justin K. Craig
- Seattle Structural Genomics Center for Infectious Disease (SSGCID), Seattle, Washington, USA
- Division of Allergy and Infectious Diseases, Center for Emerging and Re-emerging Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Kayleigh F. Barett
- Seattle Structural Genomics Center for Infectious Disease (SSGCID), Seattle, Washington, USA
- Division of Allergy and Infectious Diseases, Center for Emerging and Re-emerging Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Lynn K. Barrett
- Seattle Structural Genomics Center for Infectious Disease (SSGCID), Seattle, Washington, USA
- Division of Allergy and Infectious Diseases, Center for Emerging and Re-emerging Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Wesley C. Van Voorhis
- Seattle Structural Genomics Center for Infectious Disease (SSGCID), Seattle, Washington, USA
- Division of Allergy and Infectious Diseases, Center for Emerging and Re-emerging Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Peter J. Myler
- Seattle Structural Genomics Center for Infectious Disease (SSGCID), Seattle, Washington, USA
- Seattle Children’s Research Institute, University of Washington, Seattle, Washington, USA
| | - Krystle J. McLaughlin
- Department of Chemistry, Vassar College, 124 Raymond Avenue, Poughkeepsie, NY 12604, USA
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2
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Oliver EB, Friesen JD, Walker JA, Peters SJ, Weitzel CS, Friesen JA. Characterization of an archaeal inorganic pyrophosphatase from Sulfolobus islandicus using a [ 31P]-NMR-based assay. Biochem Biophys Res Commun 2021; 585:8-14. [PMID: 34781059 DOI: 10.1016/j.bbrc.2021.11.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 11/04/2021] [Indexed: 11/17/2022]
Abstract
Inorganic pyrophosphatase catalyzes the conversion of pyrophosphate to phosphate and is often critical for driving reactions forward in cellular processes such as nucleic acid and protein synthesis. Commonly used methods for quantifying pyrophosphatase enzyme activity employ reacting liberated phosphate with a second molecule to produce absorbance changes or employing a second enzyme in coupled reactions to produce a product with a detectable absorbance. In this investigation, a novel [31P]-NMR spectroscopy-based assay was used to quantitatively measure the formation of phosphate and evaluate the activity of inorganic pyrophosphatase from the thermoacidophilic Crenarchaeota Sulfolobus islandicus. The enzymatic activity was directly measured via integration of the [31P] resonance associated with the phosphate product (δ = 2.1 ppm). Sulfolobus islandicus inorganic pyrophosphatase preferentially utilized Mg2+ as divalent cation and had pH and temperature optimums of 6.0 of 50 °C, respectively. The Vmax value was 850 μmol/min/mg and the Km for pyrophosphate was 1.02 mM. Sequence analysis indicates the enzyme is a Family I pyrophosphatase. Sulfolobus islandicus inorganic pyrophosphatase was shown to be inhibited by sodium fluoride with a IC50 of 2.26 mM, compared to a IC50 of 0.066 mM for yeast inorganic pyrophosphatase. These studies reveal that a [31P]-NMR spectroscopy-based assay is an effective method for analyzing catalysis by phosphate-producing enzymes.
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Affiliation(s)
- Ethan B Oliver
- Department of Chemistry, Illinois State University, Normal, IL, 61790, USA
| | - Joshua D Friesen
- Department of Chemistry, Illinois State University, Normal, IL, 61790, USA
| | - Jacob A Walker
- Department of Chemistry, Illinois State University, Normal, IL, 61790, USA
| | - Steven J Peters
- Department of Chemistry, Illinois State University, Normal, IL, 61790, USA
| | | | - Jon A Friesen
- Department of Chemistry, Illinois State University, Normal, IL, 61790, USA.
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3
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Niu H, Zhu J, Qu Q, Zhou X, Huang X, Du Z. Crystallographic and modeling study of the human inorganic pyrophosphatase 1: A potential anti-cancer drug target. Proteins 2021; 89:853-865. [PMID: 33583053 DOI: 10.1002/prot.26064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 11/09/2020] [Accepted: 01/31/2021] [Indexed: 11/10/2022]
Abstract
Inorganic pyrophosphatases (PPases) catalyze the hydrolysis of pyrophosphate to phosphates. PPases play essential roles in growth and development, and are found in all kingdoms of life. Human possess two PPases, PPA1 and PPA2. PPA1 is present in all tissues, acting largely as a housekeeping enzyme. Besides pyrophosphate hydrolysis, PPA1 can also directly dephosphorylate phosphorylated c-Jun N-terminal kinases 1 (JNK1). Upregulated expression of PPA1 has been linked to many human malignant tumors. PPA1 knockdown induces apoptosis and decreases proliferation. PPA1 is emerging as a potential prognostic biomarker and target for anti-cancer drug development. In spite of the biological and physiopathological importance of PPA1, there is no detailed study on the structure and catalytic mechanisms of mammalian origin PPases. Here we report the crystal structure of human PPA1 at a resolution of 2.4 Å. We also carried out modeling studies of PPA1 in complex with JNK1 derived phosphor-peptides. The monomeric protein fold of PPA1 is similar to those found in other family I PPases. PPA1 forms a dimeric structure that should be conserved in animal and fungal PPases. Analysis of the PPA1 structure and comparison with available structures of PPases from lower organisms suggest that PPA1 has a largely pre-organized and relatively rigid active site for pyrophosphate hydrolysis. Results from the modeling study indicate the active site of PPA1 has the potential to accommodate double-phosphorylated peptides from JNK1. In short, results from the study provides new insights into the mechanisms of human PPA1 and basis for structure-based anti-cancer drug developments using PPA1 as the target.
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Affiliation(s)
- Haiying Niu
- Department of Gynecology and Obstetrics, Tianjin First Central Hospital, Tianjin, China.,Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois, USA
| | - Jiang Zhu
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois, USA.,Department of Biochemistry and Molecular Biology, Pennsylvania State University, State College 16802, Pennsylvania, USA
| | - Quanxin Qu
- Department of Gynecology and Obstetrics, Tianjin First Central Hospital, Tianjin, China
| | - Xia Zhou
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois, USA
| | - Xiaolan Huang
- Department of Computer Science, Southern Illinois University, Carbondale, Illinois, USA
| | - Zhihua Du
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois, USA
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4
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Hu F, Huang Z, Zheng S, Wu Q, Chen Y, Lin H, Huang W, Li L. Structural and biochemical characterization of inorganic pyrophosphatase from Homo sapiens. Biochem Biophys Res Commun 2020; 533:1115-1121. [DOI: 10.1016/j.bbrc.2020.09.139] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Accepted: 09/29/2020] [Indexed: 01/23/2023]
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Mesophilic Pyrophosphatase Function at High Temperature: A Molecular Dynamics Simulation Study. Biophys J 2020; 119:142-150. [PMID: 32533942 DOI: 10.1016/j.bpj.2020.05.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 05/06/2020] [Accepted: 05/15/2020] [Indexed: 02/06/2023] Open
Abstract
The mesophilic inorganic pyrophosphatase from Escherichia coli (EcPPase) retains function at 353 K, the physiological temperature of hyperthermophilic Thermococcus thioreducens, whereas the homolog protein (TtPPase) from this hyperthermophilic organism cannot function at room temperature. To explain this asymmetric behavior, we examined structural and dynamical properties of the two proteins using molecular dynamics simulations. The global flexibility of TtPPase is significantly higher than its mesophilic homolog at all tested temperature/pressure conditions. However, at 353 K, EcPPase reduces its solvent-exposed surface area and increases subunit compaction while maintaining flexibility in its catalytic pocket. In contrast, TtPPase lacks this adaptability and has increased rigidity and reduced protein/water interactions in its catalytic pocket at room temperature, providing a plausible explanation for its inactivity near room temperature.
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Si Y, Wang X, Yang G, Yang T, Li Y, Ayala GJ, Li X, Wang H, Su J. Crystal Structures of Pyrophosphatase from Acinetobacter baumannii: Snapshots of Pyrophosphate Binding and Identification of a Phosphorylated Enzyme Intermediate. Int J Mol Sci 2019; 20:ijms20184394. [PMID: 31500178 PMCID: PMC6770254 DOI: 10.3390/ijms20184394] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Revised: 08/31/2019] [Accepted: 09/03/2019] [Indexed: 11/26/2022] Open
Abstract
All living things have pyrophosphatases that hydrolyze pyrophosphate and release energy. This energetically favorable reaction drives many energetically unfavorable reactions. An accepted catalytic model of pyrophosphatase shows that a water molecule activated by two divalent cations (M1 and M2) within the catalytic center can attack pyrophosphate in an SN2 mechanism and thus hydrolyze the molecule. However, our co-crystal structure of Acinetobacter baumannii pyrophosphatase with pyrophosphate shows that a water molecule from the solvent may, in fact, be the actual catalytic water. In the co-crystal structure of the wild-type pyrophosphatase with pyrophosphate, the electron density of the catalytic centers of each monomer are different from one another. This indicates that pyrophosphates in the catalytic center are dynamic. Our mass spectroscopy results have identified a highly conserved lysine residue (Lys30) in the catalytic center that is phosphorylated, indicating that the enzyme could form a phosphoryl enzyme intermediate during hydrolysis. Mutation of Lys30 to Arg abolished the activity of the enzyme. In the structure of the apo wild type enzyme, we observed that a Na+ ion is coordinated by residues within a loop proximal to the catalytic center. Therefore, we mutated three key residues within the loop (K143R, P147G, and K149R) and determined Na+ and K+-induced inhibition on their activities. Compared to the wild type enzyme, P147G is most sensitive to these cations, whereas K143R was inactive and K149R showed no change in activity. These data indicate that monovalent cations could play a role in down-regulating pyrophosphatase activity in vivo. Overall, our results reveal new aspects of pyrophosphatase catalysis and could assist in the design of specific inhibitors of Acinetobacter baumannii growth.
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Affiliation(s)
- Yunlong Si
- Jilin Province Key Laboratory on Chemistry and Biology of Natural Drugs in Changbai Mountain, School of Life Sciences, Northeast Normal University, Changchun 130024, China
| | - Xing Wang
- Jilin Province Key Laboratory on Chemistry and Biology of Natural Drugs in Changbai Mountain, School of Life Sciences, Northeast Normal University, Changchun 130024, China
| | - Guosong Yang
- Zhongke Biopharm Co., LTD, East of Beijing, Beijing 101601, China
| | - Tong Yang
- Jilin Province Key Laboratory on Chemistry and Biology of Natural Drugs in Changbai Mountain, School of Life Sciences, Northeast Normal University, Changchun 130024, China
| | - Yuying Li
- Jilin Province Key Laboratory on Chemistry and Biology of Natural Drugs in Changbai Mountain, School of Life Sciences, Northeast Normal University, Changchun 130024, China
| | - Gabriela Jaramillo Ayala
- Jilin Province Key Laboratory on Chemistry and Biology of Natural Drugs in Changbai Mountain, School of Life Sciences, Northeast Normal University, Changchun 130024, China
| | - Xumin Li
- Jilin Province Key Laboratory on Chemistry and Biology of Natural Drugs in Changbai Mountain, School of Life Sciences, Northeast Normal University, Changchun 130024, China
| | - Hao Wang
- Jilin Province Key Laboratory on Chemistry and Biology of Natural Drugs in Changbai Mountain, School of Life Sciences, Northeast Normal University, Changchun 130024, China
| | - Jiyong Su
- Jilin Province Key Laboratory on Chemistry and Biology of Natural Drugs in Changbai Mountain, School of Life Sciences, Northeast Normal University, Changchun 130024, China.
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7
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Crystal structures of plant inorganic pyrophosphatase, an enzyme with a moonlighting autoproteolytic activity. Biochem J 2019; 476:2297-2319. [PMID: 31371393 DOI: 10.1042/bcj20190427] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 07/26/2019] [Accepted: 08/01/2019] [Indexed: 11/17/2022]
Abstract
Inorganic pyrophosphatases (PPases, EC 3.6.1.1), which hydrolyze inorganic pyrophosphate to phosphate in the presence of divalent metal cations, play a key role in maintaining phosphorus homeostasis in cells. DNA coding inorganic pyrophosphatases from Arabidopsis thaliana (AtPPA1) and Medicago truncatula (MtPPA1) were cloned into a bacterial expression vector and the proteins were produced in Escherichia coli cells and crystallized. In terms of their subunit fold, AtPPA1 and MtPPA1 are reminiscent of other members of Family I soluble pyrophosphatases from bacteria and yeast. Like their bacterial orthologs, both plant PPases form hexamers, as confirmed in solution by multi-angle light scattering and size-exclusion chromatography. This is in contrast with the fungal counterparts, which are dimeric. Unexpectedly, the crystallized AtPPA1 and MtPPA1 proteins lack ∼30 amino acid residues at their N-termini, as independently confirmed by chemical sequencing. In vitro, self-cleavage of the recombinant proteins is observed after prolonged storage or during crystallization. The cleaved fragment corresponds to a putative signal peptide of mitochondrial targeting, with a predicted cleavage site at Val31-Ala32. Site-directed mutagenesis shows that mutations of the key active site Asp residues dramatically reduce the cleavage rate, which suggests a moonlighting proteolytic activity. Moreover, the discovery of autoproteolytic cleavage of a mitochondrial targeting peptide would change our perception of this signaling process.
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8
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Vorobyeva NN, Kurilova SA, Anashkin VA, Rodina EV. Inhibition of Escherichia coli inorganic pyrophosphatase by fructose-1-phosphate. BIOCHEMISTRY (MOSCOW) 2017; 82:953-956. [DOI: 10.1134/s0006297917080107] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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9
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Hatti K, Biswas A, Chaudhary S, Dadireddy V, Sekar K, Srinivasan N, Murthy MRN. Structure determination of contaminant proteins using the MarathonMR procedure. J Struct Biol 2017; 197:372-378. [PMID: 28167161 DOI: 10.1016/j.jsb.2017.01.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Revised: 01/21/2017] [Accepted: 01/24/2017] [Indexed: 10/20/2022]
Abstract
In the recent decades, essential steps of protein structure determination such as phasing by multiple isomorphous replacement and multi wave length anomalous dispersion, molecular replacement, refinement of the structure determined and its validation have been fully automated. Several computer program suites that execute all these steps as a pipeline operation have been made available. In spite of these great advances, determination of a protein structure may turn out to be a challenging task for a variety of reasons. It might be difficult to obtain multiple isomorphous replacement or multi wave length anomalous dispersion data or the crystal may have defects such as twinning or pseudo translation. Apart from these usual difficulties, more frequent difficulties have been encountered in recent years because of the large number of projects handled by structural biologists. These new difficulties usually result from contamination of the protein of interest by other proteins or presence of proteins from pathogenic organisms that could withstand the antibiotics used to prevent bacterial contamination. It could also be a result of poor book keeping. Recently, we have developed a procedure called MarathonMR that has the power to resolve some of these problems automatically. In this communication, we describe how the MarathonMR was used to determine four different protein structures that had remained elusive for several years. We describe the plausible reasons for the difficulties encountered in determining these structures and point out that the method presented here could be a validation tool for protein structures deposited in the protein data bank.
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Affiliation(s)
- Kaushik Hatti
- Molecular Biophysics Unit, Indian Institute of Science, Bengaluru, Karnataka 560012, India; Vittal Mallya Scientific Research Foundation, Kanakapura Road, Bengaluru, Karnataka 560062, India
| | - Ansuman Biswas
- Physics Department, Indian Institute of Science, Bengaluru, Karnataka 560062, India
| | - Santosh Chaudhary
- Physics Department, Indian Institute of Science, Bengaluru, Karnataka 560062, India
| | | | - Kanagaraj Sekar
- Department of Computational and Data Sciences, Indian Institute of Science, Bengaluru, Karnataka 560062, India
| | | | - Mathur R N Murthy
- Molecular Biophysics Unit, Indian Institute of Science, Bengaluru, Karnataka 560012, India.
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10
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Immobilization of inorganic pyrophosphatase on nanodiamond particles retaining its high enzymatic activity. Biointerphases 2015; 10:041005. [DOI: 10.1116/1.4934483] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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11
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Jamwal A, Round AR, Bannwarth L, Venien-Bryan C, Belrhali H, Yogavel M, Sharma A. Structural and Functional Highlights of Vacuolar Soluble Protein 1 from Pathogen Trypanosoma brucei brucei. J Biol Chem 2015; 290:30498-513. [PMID: 26494625 DOI: 10.1074/jbc.m115.674176] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Indexed: 11/06/2022] Open
Abstract
Trypanosoma brucei (T. brucei) is responsible for the fatal human disease called African trypanosomiasis, or sleeping sickness. The causative parasite, Trypanosoma, encodes soluble versions of inorganic pyrophosphatases (PPase), also called vacuolar soluble proteins (VSPs), which are localized to its acidocalcisomes. The latter are acidic membrane-enclosed organelles rich in polyphosphate chains and divalent cations whose significance in these parasites remains unclear. We here report the crystal structure of T. brucei brucei acidocalcisomal PPases in a ternary complex with Mg(2+) and imidodiphosphate. The crystal structure reveals a novel structural architecture distinct from known class I PPases in its tetrameric oligomeric state in which a fused EF hand domain arranges around the catalytic PPase domain. This unprecedented assembly evident from TbbVSP1 crystal structure is further confirmed by SAXS and TEM data. SAXS data suggest structural flexibility in EF hand domains indicative of conformational plasticity within TbbVSP1.
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Affiliation(s)
- Abhishek Jamwal
- From the Structural and Computational Biology Group, International Centre for Genetic Engineering and Biotechnology, New Delhi 110067, India
| | - Adam R Round
- the European Molecular Biology Laboratory, Grenoble Outstation, 38042 Grenoble, France, the Unit for Virus Host-Cell Interactions, University Grenoble Alpes-EMBL-CNRS, 38042 Grenoble, France, and
| | | | | | - Hassan Belrhali
- the European Molecular Biology Laboratory, Grenoble Outstation, 38042 Grenoble, France, the Unit for Virus Host-Cell Interactions, University Grenoble Alpes-EMBL-CNRS, 38042 Grenoble, France, and
| | - Manickam Yogavel
- From the Structural and Computational Biology Group, International Centre for Genetic Engineering and Biotechnology, New Delhi 110067, India
| | - Amit Sharma
- From the Structural and Computational Biology Group, International Centre for Genetic Engineering and Biotechnology, New Delhi 110067, India,
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12
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Kajander T, Kellosalo J, Goldman A. Inorganic pyrophosphatases: one substrate, three mechanisms. FEBS Lett 2013; 587:1863-9. [PMID: 23684653 DOI: 10.1016/j.febslet.2013.05.003] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Accepted: 05/06/2013] [Indexed: 10/26/2022]
Abstract
Soluble inorganic pyrophosphatases (PPases) catalyse an essential reaction, the hydrolysis of pyrophosphate to inorganic phosphate. In addition, an evolutionarily ancient family of membrane-integral pyrophosphatases couple this hydrolysis to Na(+) and/or H(+) pumping, and so recycle some of the free energy from the pyrophosphate. The structures of the H(+)-pumping mung bean PPase and the Na(+)-pumping Thermotoga maritima PPase solved last year revealed an entirely novel membrane protein containing 16 transmembrane helices. The hydrolytic centre, well above the membrane, is linked by a charged "coupling funnel" to the ionic gate about 20Å away. By comparing the active sites, fluoride inhibition data and the various models for ion transport, we conclude that membrane-integral PPases probably use binding of pyrophosphate to drive pumping.
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Affiliation(s)
- Tommi Kajander
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
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13
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Costa EP, Campos E, de Andrade CP, Façanha AR, Saramago L, Masuda A, da Silva Vaz I, Fernandez JH, Moraes J, Logullo C. Partial characterization of an atypical family I inorganic pyrophosphatase from cattle tick Rhipicephalus (Boophilus) microplus. Vet Parasitol 2012; 184:238-47. [DOI: 10.1016/j.vetpar.2011.09.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Revised: 08/18/2011] [Accepted: 09/05/2011] [Indexed: 10/17/2022]
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14
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Identification of new protein complexes of Escherichia coli inorganic pyrophosphatase using pull-down assay. Biochimie 2011; 93:1576-83. [DOI: 10.1016/j.biochi.2011.05.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2010] [Accepted: 05/10/2011] [Indexed: 11/20/2022]
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15
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Wu HJ, Seib KL, Srikhanta YN, Edwards J, Kidd SP, Maguire TL, Hamilton A, Pan KT, Hsiao HH, Yao CW, Grimmond SM, Apicella MA, McEwan AG, Wang AHJ, Jennings MP. Manganese regulation of virulence factors and oxidative stress resistance in Neisseria gonorrhoeae. J Proteomics 2009; 73:899-916. [PMID: 20004262 DOI: 10.1016/j.jprot.2009.12.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2009] [Revised: 11/13/2009] [Accepted: 12/01/2009] [Indexed: 01/19/2023]
Abstract
Neisseria gonorrhoeae has evolved a complex and novel network of oxidative stress responses, including defence mechanisms that are dependent on manganese (Mn). We performed systematic analyses at the transcriptomic and proteomic (1D SDS-PAGE and Isotope-Coded Affinity Tag [ICAT]) levels to investigate the global expression changes that take place in a high Mn environment, which results in a Mn-dependent oxidative stress resistance phenotype. These studies revealed that there were proteins regulated at the post-transcriptional level under conditions of increased Mn concentration, including proteins involved in virulence (e.g., pilin, a key adhesin), oxidative stress defence (e.g., superoxide dismutase), cellular metabolism, protein synthesis, RNA processing and cell division. Mn regulation of inorganic pyrophosphatase (Ppa) indicated the potential involvement of phosphate metabolism in the Mn-dependent oxidative stress defence. A detailed analysis of the role of Ppa and polyphosphate kinase (Ppk) in the gonococcal oxidative stress response revealed that ppk and ppa mutant strains showed increased resistance to oxidative stress. Investigation of these mutants grown with high Mn suggests that phosphate and pyrophosphate are involved in Mn-dependent oxidative stress resistance.
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Affiliation(s)
- Hsing-Ju Wu
- Core Facilities for Proteomics Research, Institute of Biological Chemistry, Academia Sinica, Taipei, 115, Taiwan
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Glazer DS, Radmer RJ, Altman RB. Improving structure-based function prediction using molecular dynamics. Structure 2009; 17:919-29. [PMID: 19604472 DOI: 10.1016/j.str.2009.05.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2008] [Revised: 05/06/2009] [Accepted: 05/06/2009] [Indexed: 10/20/2022]
Abstract
The number of molecules with solved three-dimensional structure but unknown function is increasing rapidly. Particularly problematic are novel folds with little detectable similarity to molecules of known function. Experimental assays can determine the functions of such molecules, but are time-consuming and expensive. Computational approaches can identify potential functional sites; however, these approaches generally rely on single static structures and do not use information about dynamics. In fact, structural dynamics can enhance function prediction: we coupled molecular dynamics simulations with structure-based function prediction algorithms that identify Ca(2+) binding sites. When applied to 11 challenging proteins, both methods showed substantial improvement in performance, revealing 22 more sites in one case and 12 more in the other, with a modest increase in apparent false positives. Thus, we show that treating molecules as dynamic entities improves the performance of structure-based function prediction methods.
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Affiliation(s)
- Dariya S Glazer
- Department of Genetics, Stanford University, Clark Center, Stanford, CA 94305, USA
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17
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Yang L, Liao RZ, Yu JG, Liu RZ. DFT study on the mechanism of Escherichia coli inorganic pyrophosphatase. J Phys Chem B 2009; 113:6505-10. [PMID: 19366250 DOI: 10.1021/jp810003w] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Escherichia coli inorganic pyrophosphatase (E-PPase) is a tetranuclear divalent metal dependent enzyme that catalyzes the reversible interconversion of pyrophosphate (PPi) and orthophosphate (Pi), with Mg(2+) conferring the highest activity. In the present work, the reaction mechanism of E-PPase is investigated using the hybrid density functional theory (DFT) method B3LYP with a large model of the active site. Our calculated results shed further light on the detailed reaction mechanism. In particular, the important residue Asp67, either protonated or unprotonated, was taken into account in the present calculations. Our calculations indicated that a protonated Asp67 is crucial for the reverse reaction to take place; however, it is lost sight of in the forward reaction. The bridging hydroxide is shown to be capable of performing nucleophilic in-line attack on the substrate from its bridging position in the presence of four Mg(2+) ions. During the catalysis, the roles of the four magnesium ions are suggested to provide a necessary conformation of the active site, facilitate the nucleophile formation and substrate orientation, and stabilize the trigonal bipyramid transition state, thereby lowering the barrier for the nucleophilic attack.
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Affiliation(s)
- Ling Yang
- College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
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18
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Lu CH, Huang SW, Lai YL, Lin CP, Shih CH, Huang CC, Hsu WL, Hwang JK. On the relationship between the protein structure and protein dynamics. Proteins 2008; 72:625-34. [PMID: 18247347 DOI: 10.1002/prot.21954] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Recently, we have developed a method (Shih et al., Proteins: Structure, Function, and Bioinformatics 2007;68: 34-38) to compute correlation of fluctuations of proteins. This method, referred to as the protein fixed-point (PFP) model, is based on the positional vectors of atoms issuing from the fixed point, which is the point of the least fluctuations in proteins. One corollary from this model is that atoms lying on the same shell centered at the fixed point will have the same thermal fluctuations. In practice, this model provides a convenient way to compute the average dynamical properties of proteins directly from the geometrical shapes of proteins without the need of any mechanical models, and hence no trajectory integration or sophisticated matrix operations are needed. As a result, it is more efficient than molecular dynamics simulation or normal mode analysis. Though in the previous study the PFP model has been successfully applied to a number of proteins of various folds, it is not clear to what extent this model will be applied. In this article, we have carried out the comprehensive analysis of the PFP model for a dataset comprising 972 high-resolution X-ray structures with pairwise sequence identity <or=25%. We found that in most cases the PFP model works well. However, in case of proteins comprising multiple domains, each domain should be treated separately as an independent dynamical module with its own fixed point; and in case of the protein complex comprising a number of subunits, if functioning as a biological unit, the whole complex should be considered as one single dynamical module with one fixed point. Under such considerations, the resultant correlation coefficient between the computed and the X-ray structural B-factors for the data set is 0.59 and 75% (727/972) of proteins with a correlation coefficient >or=0.5. Our result shows that the fixed-point model is indeed quite general and will be a useful tool for high throughput analysis of dynamical properties of proteins.
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Affiliation(s)
- Chih-Hao Lu
- Institute of Bioinformatics, National Chiao Tung University, HsinChu 30050, Taiwan, Republic of China
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19
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Rodina EV, Vorobyeva NN, Kurilova SA, Sitnik TS, Nazarova TI. ATP as effector of inorganic pyrophosphatase of Escherichia coli. The role of residue Lys112 in binding effectors. BIOCHEMISTRY (MOSCOW) 2007; 72:100-8. [PMID: 17309443 DOI: 10.1134/s0006297907010129] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
It has been shown that PP(i), methylenediphosphonate, and ATP act as effectors of Escherichia coli inorganic pyrophosphatase (E-PPase), and that they compete for binding at the allosteric regulatory site. On the basis of chemical modification and computer modeling of a structure of the enzyme-ATP complex, a number of amino acid residues presumably involved in binding effectors has been revealed. Mutant variants Lys112Gln, Lys112Gln/Lys148Gln, and Lys112Gln/Lys115Ala of E-PPase have been obtained, as well as a modified variant of wild type E-PPase ((Ad)wt PPase) with a derivative of ATP chemically attached to the amino group of Lys146. Kinetic properties of these variants have been investigated and compared to the earlier described variants Lys115Ala, Arg43Gln, and Lys148Gln. Analysis of the data confirms the proposed location of an effector binding site in a cluster of positively charged amino acid residues including the side chains of Arg43, Lys146 (subunit A), Lys112, and Lys115 (subunit B). Lys112 is supposed to play a key role in forming contacts with the phosphate groups of the three studied effectors.
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Affiliation(s)
- E V Rodina
- Chemical Faculty, Lomonosov Moscow State University, Moscow, 119992, Russia.
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20
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Rodina EV, Vorobyeva NN, Kurilova SA, Belenikin MS, Fedorova NV, Nazarova TI. ATP as effector of inorganic pyrophosphatase of Escherichia coli. Identification of the binding site for ATP. BIOCHEMISTRY (MOSCOW) 2007; 72:93-9. [PMID: 17309442 DOI: 10.1134/s0006297907010117] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The interaction of Escherichia coli inorganic pyrophosphatase (E-PPase) with effector ATP has been studied. The E-PPase has been chemically modified with the dialdehyde derivative of ATP. It has been established that in the experiment only one molecule of effector ATP is bound to each subunit of the hexameric enzyme. Tryptic digestion of the adenylated protein followed by isolation of a modified peptide by HPLC and its mass-spectrometric identification has showed that it is an amino group of Lys146 that undergoes modification. Molecular docking of ATP to E-PPase indicates that the binding site for effector ATP is located in a cluster of positively charged amino acid residues proposed earlier on the basis of site-directed mutagenesis to participate in binding of effector pyrophosphate. Molecular docking also reveals several other amino acid residues probably involved in the interaction with effectors.
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Affiliation(s)
- E V Rodina
- Chemical Faculty, Lomonosov Moscow State University, Moscow, 119992, Russia.
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21
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Samygina VR, Moiseev VM, Rodina EV, Vorobyeva NN, Popov AN, Kurilova SA, Nazarova TI, Avaeva SM, Bartunik HD. Reversible Inhibition of Escherichia coli Inorganic Pyrophosphatase by Fluoride: Trapped Catalytic Intermediates in Cryo-crystallographic Studies. J Mol Biol 2007; 366:1305-17. [PMID: 17196979 DOI: 10.1016/j.jmb.2006.11.082] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2006] [Revised: 11/29/2006] [Indexed: 11/22/2022]
Abstract
Here, we describe high-resolution X-ray structures of Escherichia coli inorganic pyrophosphatase (E-PPase) complexed with the substrate, magnesium, or manganese pyrophosphate. The structures correspond to steps in the catalytic synthesis of enzyme-bound pyrophosphate (PP(i)) in the presence of fluoride as an inhibitor of hydrolysis. The catalytic reaction intermediates were trapped applying a new method that we developed for initiating hydrolytic activity in the E-PPase crystal. X-ray structures were obtained for three consecutive states of the enzyme in the course of hydrolysis. Comparative analysis of these structures showed that the Mn2+-supported hydrolysis of the phosphoanhydride bond is followed by a fast release of the leaving phosphate from the P1 site. The electrophilic phosphate P2 is trapped in the "down" conformation. Its movement into the "up" position most likely represents the rate-limiting step of Mn2+-supported hydrolysis. We further determined the crystal structure of the Arg43Gln mutant variant of E-PPase complexed with one phosphate and four Mn ions.
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Affiliation(s)
- V R Samygina
- A.V. Shubnikov Institute of Crystallography, Russian Academy of Sciences, Leninsky Pr. 59, 119333 Moscow, Russia.
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22
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Chao TC, Huang H, Tsai JY, Huang CY, Sun YJ. Kinetic and structural properties of inorganic pyrophosphatase from the pathogenic bacterium Helicobacter pylori. Proteins 2007; 65:670-80. [PMID: 16988955 DOI: 10.1002/prot.21093] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Inorganic pyrophosphatase (PPase) catalyzes the hydrolysis of pyrophosphate (PPi) to orthophosphate (Pi) and controls the level of PPi in cells. PPase plays an essential role in energy conservation and provides the energy for many biosynthetic pathways. The Helicobacter pylori pyrophosphatase (HpPPase) gene was cloned, expressed, purified, and found to have a molecular weight of 20 kDa. The K(m) and V (max) of HpPPase were determined as 214.4 microM and 594 micromol Pi min(-1) mg(-1), respectively. PPi binds Mg(2+) to form a true substrate that activates the enzyme. However, free PPi could be a potent inhibitor for HpPPase. The effects of the inhibitors NaF, ATP, iminodiphosphate, and N-ethylmaleimide on HpPPase activity were evaluated. NaF showed the highest inhibition of the enzyme. Crystal structures of HpPPase and the PPi-HpPPase complex were determined. HpPPase comprises three alpha-helices and nine beta-strands and folds as a barrel structure. HpPPase forms a hexamer in both the solution and crystal states, and each monomer has its own PPi-binding site. The PPi binding does not cause a significant conformational change in the PPi-HpPPase complex, which might represent an inhibition state for HpPPase in the absence of a divalent metal ion.
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Affiliation(s)
- Ti-Chun Chao
- Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu 300, Taiwan, Republic of China
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23
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Andreeva NS. State-of-the-art and problems of X-ray diffraction analysis of biomacromolecules. CRYSTALLOGR REP+ 2006. [DOI: 10.1134/s1063774506060095] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Abstract
In this report, we demonstrate that phylogenetic motifs, sequence regions conserving the overall familial phylogeny, represent a promising approach to protein functional site prediction. Across our structurally and functionally heterogeneous data set, phylogenetic motifs consistently correspond to functional sites defined by both surface loops and active site clefts. Additionally, the partially buried prosthetic group regions of cytochrome P450 and succinate dehydrogenase are identified as phylogenetic motifs. In nearly all instances, phylogenetic motifs are structurally clustered, despite little overall sequence proximity, around key functional site features. Based on calculated false-positive expectations and standard motif identification methods, we show that phylogenetic motifs are generally conserved in sequence. This result implies that they can be considered motifs in the traditional sense as well. However, there are instances where phylogenetic motifs are not (overall) well conserved in sequence. This point is enticing, because it implies that phylogenetic motifs are able to identify key sequence regions that traditional motif-based approaches would not. Further, phylogenetic motif results are also shown to be consistent with evolutionary trace results, and bootstrapping is used to demonstrate tree significance.
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Affiliation(s)
- David La
- Department of Biological Sciences, California State Polytechnic University, Pomona, California 91768, USA
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25
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Moiseev VM, Rodina EV, Kurilova SA, Vorobyeva NN, Nazarova TI, Avaeva SM. Substitutions of Glycine Residues Gly100 and Gly147 in Conservative Loops Decrease Rates of Conformational Rearrangements of Escherichia coli Inorganic Pyrophosphatase. BIOCHEMISTRY (MOSCOW) 2005; 70:858-66. [PMID: 16212541 DOI: 10.1007/s10541-005-0195-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Escherichia coli inorganic pyrophosphatase (PPase) is a one-domain globular enzyme characterized by its ability to easily undergo minor structure rearrangements involving flexible segments of the polypeptide chain. To elucidate a possible role of these segments in catalysis, catalytic properties of mutant variants of E. coli PPase Gly100Ala and Gly147Val with substitutions in the conservative loops II and III have been studied. The main result of the mutations was a sharp decrease in the rates of conformational changes required for binding of activating Mg2+ ions, whereas affinity of the enzyme for Mg2+ was not affected. The pH-independent parameters of MgPP(i) hydrolysis, kcat and kcat/Km, have been determined for the mutant PPases. The values of kcat for Gly100Ala and Gly147Val variants were 4 and 25%, respectively, of the value for the native enzyme. Parameter kcat/Km for both mutants was two orders of magnitude lower. Mutation Gly147Val increased pH-independent Km value about tenfold. The study of synthesis of pyrophosphate in the active sites of the mutant PPases has shown that the maximal level of synthesized pyrophosphate was in the case of Gly100Ala twofold, and in the case of Gly147Val fivefold, higher than for the native enzyme. The results reported in this paper demonstrate that the flexibility of the loops where the residues Gly100 and Gly147 are located is necessary at the stages of substrate binding and product release. In the case of Gly100Ala PPase, significant impairment of affinity of enzyme effector site for PP(i) was also found.
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Affiliation(s)
- V M Moiseev
- Faculty of Chemistry, Lomonosov Moscow State University, Moscow, 119992, Russia.
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26
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Sitnik TS, Avaeva SM. [A cationic cluster of amino acid residues of inorganic pyrophosphatase from Escherichia coli as a possible site of effector binding]. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2005; 31:251-8. [PMID: 16004383 DOI: 10.1007/s11171-005-0031-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A computer-assisted analysis of the molecule of Escherichia coli pyrophosphatase was earlier used to localize the site capable of binding free pyrophosphate or methylene diphosphonate, a PPi analogue, and thereby activating the enzyme. A cluster of positively charged amino acid residues (Lys146, Lys148, Lys115, and Arg43) was revealed, and Lys115Ala, Lys148Gln, and Arg43Gln mutant pyrophosphatases (PPases) were obtained. It was shown that the kinetics of hydrolysis of the magnesium pyrophosphate (MgPPi) substrate by these mutant variants does not obey the Michaelis-Menten equation, which is expressed in two slopes in the double-reciprocal plot of the enzyme reaction rate vs. substrate concentration. The two regions on the curves correspond to the ranges of high and low MgPPi concentrations. This suggests that, in all mutant variants of the enzyme, the binding of PPi at the effector site becomes worse, whereas the affinity of MgPPi for the active site remains practically unchanged. Other properties of the enzymes, such as its oligomeric state, resistance to thermal denaturation, and resistance to the denaturing agent guanidine hydrochloride, were thoroughly studied. The constants of binding of Mg2+ to mutant enzymes in the absence of the substrate and to enzyme-substrate complexes were determined. The introduction of amino acid substitutions was shown to stabilize the protein globule. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2005, vol. 31, no. 3; see also http://www.maik.ru.
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27
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Halonen P, Tammenkoski M, Niiranen L, Huopalahti S, Parfenyev AN, Goldman A, Baykov A, Lahti R. Effects of Active Site Mutations on the Metal Binding Affinity, Catalytic Competence, and Stability of the Family II Pyrophosphatase from Bacillus subtilis. Biochemistry 2005; 44:4004-10. [PMID: 15751976 DOI: 10.1021/bi047926u] [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: 11/29/2022]
Abstract
Family II inorganic pyrophosphatases (PPases) have been recently found in a variety of bacteria. Their primary and tertiary structures differ from those of the well-known family I PPases, although both have a binuclear metal center directly involved in catalysis. Here, we examined the effects of mutating one Glu, four His, and five Asp residues forming or close to the metal center on Mn(2+) binding affinity, catalysis, oligomeric structure, and thermostability of the family II PPase from Bacillus subtilis (bsPPase). Mutations H9Q, D13E, D15E, and D75E in two metal-binding subsites caused profound (10(4)- to 10(6)-fold) reductions in the binding affinity for Mn(2+). Most of the mutations decreased k(cat) for MgPP(i) by 2-3 orders of magnitude when measured with Mn(2+) or Mg(2+) bound to the high-affinity subsite and Mg(2+) bound to both the low-affinity subsite and pyrophosphate. In the E78D variant, the k(cat) for the Mn-bound enzyme was decreased 120-fold, converting bsPPase from an Mn-specific to an Mg-specific enzyme. K(m) values were less affected by the mutations, and, interestingly, were decreased in most cases. Mutations of His(97) and His(98) residues, which lie near the subunit interface, greatly destabilized the bsPPase dimer, whereas most other mutations stabilized it. Mn(2+), in sharp contrast to Mg(2+), conferred high thermostability to wild-type bsPPase, although this effect was reduced by all of the mutations except D203E. These results indicate that family II PPases have a more integrated active site structure than family I PPases and are consequently more sensitive to conservative mutations.
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Affiliation(s)
- Pasi Halonen
- Department of Biochemistry, University of Turku, FIN-20014 Turku, Finland
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28
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Vainonen JP, Vorobyeva NN, Rodina EV, Nazarova TI, Kurilova SA, Skoblov JS, Avaeva SM. Metal-free PPi activates hydrolysis of MgPPi by an Escherichia coli inorganic pyrophosphatase. BIOCHEMISTRY (MOSCOW) 2005. [DOI: 10.1007/pl00021760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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29
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Vainonen JP, Vorobyeva NN, Rodina EV, Nazarova TI, Kurilova SA, Skoblov JS, Avaeva SM. Metal-free PPi activates hydrolysis of MgPPi by an Escherichia coli inorganic pyrophosphatase. BIOCHEMISTRY (MOSCOW) 2005. [DOI: 10.1007/s10541-005-0053-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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30
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Zimenkov YV, Salminen A, Efimova IS, Lahti R, Baykov AA. Cd2+-induced aggregation of Escherichia coli pyrophosphatase. ACTA ACUST UNITED AC 2004; 271:3064-7. [PMID: 15233803 DOI: 10.1111/j.1432-1033.2004.04239.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report here that Escherichia coli pyrophosphatase aggregates in the presence of millimolar Cd(2+). This highly cooperative process was specific to both the metal ion and the protein and could be reversed fully by decreasing the Cd(2+) concentration. Aggregation was enhanced by Mg(2+), the natural cofactor of pyrophosphatase, and Mn(2+). Mutations at the intersubunit metal-binding site had no effect, whereas mutation at Glu139, which is part of the peripheral metal-binding site found in pyrophosphatase crystals near the contact region between two enzyme molecules, suppressed aggregation. These findings indicate that aggregation is affected by Cd(2+) binding to the peripheral metal-binding site, probably by strengthening intermolecular Trp149-Trp149' stacking interactions.
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Affiliation(s)
- Yury V Zimenkov
- A. N. Belozersky Institute of Physico-Chemical Biology and School of Chemistry, Moscow State University, Moscow, Russia
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31
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Gómez-García MR, Ruiz-Pérez LM, González-Pacanowska D, Serrano A. A novel calcium-dependent soluble inorganic pyrophosphatase from the trypanosomatidLeishmania major. FEBS Lett 2004; 560:158-66. [PMID: 14988016 DOI: 10.1016/s0014-5793(04)00097-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2003] [Revised: 12/24/2003] [Accepted: 01/21/2004] [Indexed: 11/28/2022]
Abstract
A single-copy gene IPP encoding a putative soluble inorganic pyrophosphatase (LmsPPase, EC 3.6.1.1) was identified in the genome of the parasite protozoan Leishmania major. The full-length coding sequence (ca. 0.8 kb) was obtained from genomic DNA by polymerase chain reaction (PCR) and cloned into an Escherichia coli expression vector, and was overexpressed for functional protein purification and characterization. The recombinant LmsPPase, purified to electrophoretic homogeneity by a two-step chromatography procedure, exhibited a predicted molecular mass of ca. 30 kDa. The enzyme has an absolute requirement for divalent cations, exhibits a pH optimum of 7.5-8.0 and does not hydrolyze polyphosphates or adenosine triphosphate (ATP). LmsPPase differs from previously studied soluble pyrophosphatases with respect to cation selectivity, Ca(2+) being far more effective than Mg(2+). Comparisons to known sPPases show a short N-terminal extension predicted to be a mitochondrial transit peptide, and changes in active-site residues and the neighboring region. Subcellular fractionation of L. major promastigotes suggests a mitochondrial localization. Molecular phylogenetic analysis indicates that LmsPPase is a highly divergent eukaryotic Family I sPPase, perhaps an ancestral class of eukaryotic sPPases functionally adapted to a calcium-rich, probably mitochondrial, environment.
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Affiliation(s)
- María R Gómez-García
- Instituto de Parasitología y Biomedicina López-Neyra, CSIC, c/Ventanilla n degrees 11, 18001 Granada, Spain
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32
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Zyryanov AB, Vener AV, Salminen A, Goldman A, Lahti R, Baykov AA. Rates of Elementary Catalytic Steps for Different Metal Forms of the Family II Pyrophosphatase from Streptococcus gordonii. Biochemistry 2003; 43:1065-74. [PMID: 14744152 DOI: 10.1021/bi0357513] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Soluble inorganic pyrophosphatases (PPases) form two nonhomologous families, denoted I and II, that have similar active-site structures but different catalytic activities and metal cofactor specificities. Family II PPases, which are often found in pathogenic bacteria, are more active than family I PPases, and their best cofactor is Mn(2+) rather than Mg(2+), the preferred cofactor of family I PPases. Here, we present results of a detailed kinetic analysis of a family II PPase from Streptococcus gordonii (sgPPase), which was undertaken to elucidate the factors underlying the different properties of family I and II PPases. We measured rates of PP(i) hydrolysis, PP(i) synthesis, and P(i)/water oxygen exchange catalyzed by sgPPase with Mn(2+), Mg(2+), or Co(2+) in the high-affinity metal-binding site and Mg(2+) in the other sites, as well as the binding affinities for several active-site ligands (metal cofactors, fluoride, and P(i)). On the basis of these data, we deduced a minimal four-step kinetic scheme and evaluated microscopic rate constants for all eight relevant reaction steps. Comparison of these results with those obtained previously for the well-known family I PPase from Saccharomyces cerevisiae (Y-PPase) led to the following conclusions: (a) catalysis by sgPPase does not involve the enzyme-PP(i) complex isomerization known to occur in family I PPases; (b) the values of k(cat) for the magnesium forms of sgPPase and Y-PPase are similar because of similar rates of bound PP(i) hydrolysis and product release; (c) the marked acceleration of sgPPase catalysis in the presence of Mn(2+) and Co(2+) results from a combined effect of these ions on bound PP(i) hydrolysis and P(i) release; (d) sgPPase exhibits lower affinity for both PP(i) and P(i); and (e) sgPPase and Y-PPase exhibit similar values of k(cat)/K(m), which characterizes the PPase efficiency in vivo (i.e., at nonsaturating PP(i) concentrations).
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Affiliation(s)
- Anton B Zyryanov
- A. N. Belozersky Institute of Physico-Chemical Biology and School of Chemistry, Moscow State University, Moscow 119899, Russia
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33
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Graham DE, Xu H, White RH. A member of a new class of GTP cyclohydrolases produces formylaminopyrimidine nucleotide monophosphates. Biochemistry 2002; 41:15074-84. [PMID: 12475257 DOI: 10.1021/bi0268798] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The hyperthermophilic euryarchaeon Methanococcus jannaschii has no recognizable homologues of the canonical GTP cyclohydrolase enzymes that are required for riboflavin and pteridine biosyntheses. Instead, it uses a new type of thermostable GTP cyclohydrolase enzyme that produces 2-amino-5-formylamino-6-ribofuranosylamino-4(3H)-pyrimidinone ribonucleotide monophosphate and inorganic phosphate. Whereas canonical GTP cyclohydrolases produce this formylamino-pyrimidine nucleotide as a reaction intermediate, this compound is shown to be an end product of the purified recombinant M.jannaschii enzyme. Unlike other enzymes that hydrolyze the alpha-beta phosphate anhydride bond of GTP, this new enzyme completely hydrolyzes pyrophosphate to inorganic phosphate. As a result, the enzyme has a steady-state turnover of 21 min(-)(1), which is much faster than those of canonical GTP cyclohydrolase enzymes. The effects of substrate analogues and inhibitors suggest that the GTP cyclohydrolase and pyrophosphate phosphohydrolase activities occur at independent sites, although both activities depend on Mg(2+).
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Affiliation(s)
- David E Graham
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg 24061-0308, USA
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