DOCSLIB.ORG

Molybdate Pumping Into the Molybdenum Storage Protein Via an ATP-Powered Piercing Mechanism

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Molybdate Pumping Into the Molybdenum Storage Protein Via an ATP-Powered Piercing Mechanism Molybdate pumping into the molybdenum storage protein via an ATP-powered piercing mechanism Steffen Brünlea,1,2, Martin L. Eisingera,1, Juliane Poppea, Deryck J. Millsb, Julian D. Langera, Janet Vonckb, and Ulrich Ermlera,2 aDepartment of Molecular Membrane Biology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany; and bDepartment of Structural Biology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany Edited by Robert Huber, Max Planck Institute of Biochemistry, Planegg-Martinsried, Germany, and approved November 6, 2019 (received for review July 29, 2019) The molybdenum storage protein (MoSto) deposits large amounts that are covalently or noncovalently linked with the polypep- of molybdenum as polyoxomolybdate clusters in a heterohexameric tide (8, 10) vary between 3 and 14 Mo atoms and are termed (αβ)3 cage-like protein complex under ATP consumption. Here, we Mo3, Mo8, Mo5-7, hexagonal (bi)pyramidal Mo7-8, and Mo8-14 suggest a unique mechanism for the ATP-powered molybdate clusters (Fig. 1). pumping process based on X-ray crystallography, cryoelectron mi- Outside the cage, these POM clusters would be instable. On croscopy, hydrogen-deuterium exchange mass spectrometry, and the other hand, molybdate and other transition metal oxide an- mutational studies of MoSto from Azotobacter vinelandii.First, ions spontaneously polymerize to an enormous variety of POM we show that molybdate, ATP, and Mg2+ consecutively bind into clusters favorably in acidic solutions. Their investigation is an old the open ATP-binding groove of the β-subunit, which thereafter but still productive research field in inorganic chemistry (12, 13). becomes tightly locked by fixing the previously disordered N- The occurrence of POM clusters in the cage is therefore based terminal arm of the α-subunit over the β-ATP. Next, we propose a on an interplay between the inherent property of molybdate of nucleophilic attack of molybdate onto the γ-phosphate of β-ATP, self-assembly and the capability of proteins to bind/template/ analogous to the similar reaction of the structurally related UMP encapsulate them (8). kinase. The formed instable phosphoric-molybdic anhydride becomes Both subunits architecturally belong to the amino acid kinase immediately hydrolyzed and, according to the current data, the re- family, with UMP and acetylglutamate kinases as prominent leased and accelerated molybdate is pressed through the cage wall, members (14, 15) and host binding sites for ATP termed α- and BIOCHEMISTRY presumably by turning aside the Metβ149 side chain. A structural β-ATP, respectively. Previous studies have indicated that α-ATP comparison between MoSto and UMP kinase provides valuable in- sight into how an enzyme is converted into a molecular machine Significance during evolution. The postulated direct conversion of chemical en- ergy into kinetic energy via an activating molybdate kinase and an This study on the cage-like molybdenum storage protein (MoSto) exothermic pyrophosphatase reaction to overcome a proteinous bar- provides detailed insight into how nature realizes molybdenum rier represents a novelty in ATP-fueled biochemistry, because nor- biomineralization. Our data support the occurrence of molybdate mally, ATP hydrolysis initiates large-scale conformational changes to kinase and pyrophosphatase reactions in MoSto to pump mo- drive a distant process. lybdate into the locked inner protein cage against a molybdate gradient. The high molybdate concentration in the cage causes ATP | soluble molybdate pump | molybdate kinase | polyoxometalate a protein-assisted self-assembly process of molybdate to poly- cluster | protein structure oxomolybdate clusters by which approximately 130 Mo are deposited in a compact manner. We believe that this molyb- ature uses ATP binding/hydrolysis and subsequent ADP/ date pumping expands the known mechanistic repertoire of Nphosphate release for driving manifold biochemical processes, ATP-powered processes, since the chemical energy of hy- including those in energy metabolism, active transport, DNA rep- drolysis of the phosphoric-molybdic anhydride intermediate lication and maintenance, translation of genetic information, mo- would be conveyed onto the molybdate for penetration of tility, and protein (un)folding. An unusual ATP-powered process is the cage wall and not onto the protein for pore opening via accomplished by the molybdenum storage protein (MoSto) offer- conformational changes. ing some N2-fixing bacteria a pronounced selection advantage against competitors for Mo (1–3), which is only variably available in Author contributions: U.E. initiated the project; S.B. designed expression constructs and their habitats. N -fixing bacteria continuously demand Mo in form variants; S.B. overproduced, crystallized, and determined X-ray structures; M.L.E. and 2 J.D.L. designed HDX-MS experiments; M.L.E. performed HDX-MS experiments; J.P. was of molybdate for synthesizing the FeMo cofactor of nitrogenases involved in some X-ray structural studies; S.B., D.J.M., and J.V. performed cryo-EM sample (4, 5). MoSto use ATP hydrolysis to deposit approximately 130 Mo preparation, data collection, image processing, and model building; and S.B., M.L.E, J.V., over longer periods in a compact and polypeptide-fixed manner and U.E. wrote the paper. as discrete, structurally diverse, and rather instable polynuclear The authors declare no competing interest. Mo(VI)-O or polyoxometalate (POM) clusters (6–8). In com- This article is a PNAS Direct Submission. parison, Fe is biomineralized by precipitating a large and highly Published under the PNAS license. stable but less defined iron-oxygen adduct inside the ferritin Data deposition: The X-ray models reported in this paper have been deposited in the cavity by oxidizing Fe(II) to Fe(III) (9). Research Collaboratory for Structural Bioinformatics Protein Data Bank, https://www.rcsb. β The MoSto of Azotobacter vinelandii is a heterohexameric org/ (PDB ID codes 6RIS [K 42S], 6RKE [P212121], and 6RIJ [P6422]). The cryo-EM map and αβ α the corresponding model have been deposited in the Electron Microscopy Data Bank ( )3 cage-like structure (7, 8). The 3 -subunits, related by a 3-fold (accession no. EMD-4907) and the Protein Data Bank (PDB ID code 6RKD). axis, form one-half of the cage, and the architecturally similar 1S.B. and M.L.E. contributed equally to this work. β -subunits form the other half in an equivalent manner (Fig. 1). 2To whom correspondence may be addressed. Email: [email protected] or ulrich. The interior of the cage serves as a container for up to approxi- [email protected]. mately 12 POM clusters, whose structures are determined by This article contains supporting information online at https://www.pnas.org/lookup/suppl/ specific pockets inside the cage, the 3-fold symmetry, and the doi:10.1073/pnas.1913031116/-/DCSupplemental. preparation conditions (10, 11). The polynuclear Mo-O aggregates First published December 6, 2019. www.pnas.org/cgi/doi/10.1073/pnas.1913031116 PNAS | December 26, 2019 | vol. 116 | no. 52 | 26497–26504 Downloaded by guest on September 29, 2021 Fig. 1. The (αβ)3 hexameric MoSto structure. (A) MoSto is characterized by a cage-like architecture with a completely locked cavity, formed by 3 α-subunits (green) and 3 β-subunits (blue). (B) Removing 1 α- and β-subunit at the front side of MoSto reveals the inner cage, filled with POM clusters. Mo atoms of each POM cluster are depicted as different-colored spheres (Mo3, yellow; hexagonal bipyramidal Mo8, blue; Mo5, wheat; covalent and noncovalent Mo8, cyanand orange; Mo14, pink). The topologies of 4 POM clusters are also depicted as polyhedra (in the same color) formed by oxygens at the vertices that link the metals in a corner- and edge-sharing manner. Each subunit hosts a binding site for ATP, termed α-ATP or β-ATP (sticks), accessible from the outside of the cage. is more strongly bound and β-ATP significantly more weakly bound homogeneously bound ATP in the β-ATP–binding groove (Fig. 2) to MoSto, and that the hydrolysis of ATP to ADP and phosphate is with no undefined surrounding electron density as is found in most strictly coupled to POM cluster assembly inside the cage (16). of the previously reported MoSto structures (16). The absence of + Mg2 was detectable only in the α-ATP–binding site but never in the Lysβ42 side chain implicates a shorter hydrogen bond distance the β-ATP–binding site. Consequently, due to the strict depen- between Lysβ189 and the β-phosphate oxygen and, concomitantly, 2+ dency on Mg for ATP hydrolysis, the α-ATP–binding site has a 0.5-Å shift of the entire β-ATP away from the cage (Fig. 2). This been considered as the motor for molybdate pumping. The MoSto result definitively proves a pivotal function of the β-ATP–binding A. vinelandii of occurs in the MoStozero,MoStobasal, and MoStofunct site in Mo pumping. states containing neither ATP/ADP nor POM clusters, only ATP/ADP and both ATP/ADP and POM clusters, respectively The Cryoelectron Microscopy Structure of MoSto. Cryo-grids were (16). In the MoStofunct state, the cell can be supplied with mo- prepared with a freshly purified MoSto solution supplemented + lybdate on request. with molybdate and ATP/Mg2 to adjust turnover conditions such Several lines of evidence indicate that POM cluster storage that the obtained MoSto structure reflects a functionally active is separated into a rapid ATP hydrolysis-dependent molybdate state. This was uncertain for the P6322 crystal structure, because transport across the proteinous cage wall and a slow protein- molybdate loading in the crystalline state is infeasible. From the assisted self-assembly of the POM clusters promoted by the high 1,238 micrographs recorded on a JEOL 3200 FSC microscope, molybdate concentrations inside the cage (16). Despite establish- ing MoSto as a soluble, ATP-driven molybdate pump, the role of the 2 different ATP-binding sites, their potential communication, the entry site of molybdate, and in particular, the coupling mech- anism of ATP hydrolysis with molybdate translocation remain unknown and are largely answered in this work.
Load more

Recommended publications
  • Molybdates: an Alternative to Hexavalent Chromates in Corrosion
    Molybdates: An Alternative to Hexavalent Chromates 3ytzt7n2 in Corrosion Prevention and Control qz ,+ B3 F Stiles C. Thompson Sverdrup Technology, Inc. 626 Anchors St. NW Fort Walton Beach, FL 32548 (904) 833-7600 Introduction Hexavalent chromates have been the preferred corrosion inhibitor in military systems for years. Chromate conversion coatings are specified in MIL-STD-808, “Finishes, Materials and Processes for Corrosion Prevention and Control in Support Equipment ”, for aluminum, magnesium, and plated steel. A number of primers are formulated with zinc or strontium chromate. Passivation treatments for stainless steels frequently specify chromic acid. Some anodic coatings specify baths containing chromic and sulfuric acid and a pcst treatment or rinse with aqueous sodium dichromate. Even water-based primers formulated for volatile organic I compound (VOC) compliance in such areas as southern California contain chromate-based corrosion inhibitors. Chromates are decreasing in industrial use, however, as concerns about their environmental risks and toxicity increase. One pollution prevention approach is to substitute analogs of chromates in similar applications. Molybdate is one such analog of lower toxicity. Federal Environmental Regulations A number of environmental regulations now control hexavalent chromate. Toxic Substances Control Act (TSCA). Under TSCA, the Environmental Protection Agency @PA) must be notified 90 days prior to manufacture. EPA may restrict or prohibit manufacture where there is unreasonable risk to the environment. EPA also has the authority to require testing for health or environmental effects. No current regulation specifies molybdate. Resource Conservation and Recovery Act (RCRA). RCRA regulates the treatment, storage, transportation, and disposal of hazardous waste (HW). The EPA HW number for hexavalent chromium is D007.
    [Show full text]
  • A Titrimetric Determination of Thorium John J
    Ames Laboratory ISC Technical Reports Ames Laboratory 6-1954 A titrimetric determination of thorium John J. Ford Iowa State College James S. Fritz Iowa State College Follow this and additional works at: http://lib.dr.iastate.edu/ameslab_iscreports Part of the Chemistry Commons Recommended Citation Ford, John J. and Fritz, James S., "A titrimetric determination of thorium" (1954). Ames Laboratory ISC Technical Reports. 92. http://lib.dr.iastate.edu/ameslab_iscreports/92 This Report is brought to you for free and open access by the Ames Laboratory at Iowa State University Digital Repository. It has been accepted for inclusion in Ames Laboratory ISC Technical Reports by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. A titrimetric determination of thorium Abstract A rapid, accurate method for thorium is proposed in which thorium is titrated with a standard solution of ethylenediaminetetraacetic acid (EDTA). Alizarin Red S serves as the indicator, a sharp change from pink to yellow marking the end point of the titration. The method is selective for thorium although several cations and anions interfere. A preliminary extraction of thorium nitrate by mentyl oxide provides an excellent separation of thorium from most interfering ions. Keywords Ames Laboratory Disciplines Chemistry This report is available at Iowa State University Digital Repository: http://lib.dr.iastate.edu/ameslab_iscreports/92 Physical 'cieuccs Re· dmg Room UNITED STATES ATOMIC ENERGY COMMISSION ISC-520 A TITRIMETRIC DETERMINATION OF THORIUM By John J. Ford James S. Fritz June 1954 Technical Information Service, Oak Ridge, Tennessee J Subject Category, CHEMISTRY. Work performed under Contract No.
    [Show full text]
  • FALL2015.Pdf
    Introducing… In Meso In Situ Serial Crystallography mitegen.com/imisx Easy Crystallizaon in LCP • Simple in situ X-ray Diffracon • Standard Goniometer Compable • Serial Crystallography Enabling • Advanced Dual-Sandwich Design Rethink what your LCP crystallizaon plate is capable of. EZ-Cut LCP LCP Tools Easy Access LCP Crystallizaon Plate Starter Kits, Syringes, Lipids & More Take your crystallizaon in LCP to the next level with MiTeGen’s new LCP line mitegen.com/lcp ACA - Structure Matters www.AmerCrystalAssn.org Table of Contents 2 President’s Column 2-4 News from Canada 4 From the Editor's Desk 5-6 Update on Structural Dynamics Chris Cahill 7 What's on the Cover ACA President 8-11 Poster Prizes in Philadelphia 12 Undergraduate Student Reception in Philadelphia Contributors to this Issue What's on the Cover 13-51 Philadelphia ACA Meeting Page 7 21 Index of Advertisers 53-54 2015 ACA Summer Course 56 What's New on the ACA History Website Spotlight on Stamps Juanma García-Ruiz Net RefleXions 15 Plenary Lecturer in Philadelphia 58-59 Puzzle Corner 59 YSSIG Activities 60-61 48th Erice International School of Crystallography 61-62 Updates from 2014-2015 AIP Science & Technology Fellows 62 CSD50 Symposium Daniel Rabinovich 64-65 News & Awards Spotlight on Stamps 65-66 Book Reviews 66-67 2015 Wisconsin Crystal-Growing Competition 68 Net RefleXions 69 CCDC Data Deposition Service Enhancement 70-71 ACA 2016 Denver Preview 72 Future Meetings Anastasiya Vinokur Net RefleXions Contributions to ACA RefleXions may be sent to either of the Editors: Please address matters pertaining to advertisements, membership Judith L.
    [Show full text]
  • Tungsten Removal from Molybdate Solutions Using Chelating Ion-Exchange Resin: Equilibrium Adsorption Isotherm and Kinetics
    J. Cent. South Univ. (2016) 23: 1052−1057 DOI: 10.1007/s11771-016-0354-y Tungsten removal from molybdate solutions using chelating ion-exchange resin: Equilibrium adsorption isotherm and kinetics ZHU Xian-zheng(朱先正), HUO Guang-sheng(霍广生), NI Jie(倪捷), SONG Qiong(宋琼) School of Metallurgy and Environment, Central South University, Changsha 410083, China © Central South University Press and Springer-Verlag Berlin Heidelberg 2016 Abstract: The equilibrium adsorption isotherm and kinetic of the sorption process for W and Mo on macro chelating resin D403 were investigated on single Na2MoO4 and Na2WO4 solutions. The sorption isotherm results show that the adsorption process of W obeys the Freundlich model very well whereas the exchange process with Mo approximately follows the Henry model. The kinetic experiments show that the intraparticle diffusion process was the rate-determining step for W sorption on the resin, and the corresponding activation energy is calculated to be 21.976 kJ/mol. Key words: tungsten; molybdate; ion-exchange resin; isotherms; kinetics tin (IV) oxide hydrate [14], that would preferentially 1 Introduction form precipitations with W under certain conditions. The separation was effective but a large number of The separation between W and Mo has been a precipitation agents were required and the impurity ions national difficulty due to their extremely similar accompanied with the added reagents were inevitable, physicochemical properties, resulting from the increasing the impurity-removal burden. lanthanide contraction [1]. Additionally, according to the Inspired by the different affinities towards O industrial requirement, WO3 impurity in final ammonium between W and Mo, we discovered a novel resin (D403) molybdate product should be restricted to below containing meglumine group which exhibited marvelous 150×10−6 (mass fraction) [2], making W removal from separation effects between Mo and W at pH above 8.0, at molybdate solutions particularly important.
    [Show full text]
  • A High-Affinity Molybdate Transporter in Eukaryotes
    A high-affinity molybdate transporter in eukaryotes Manuel Tejada-Jime´ nez, Angel´ Llamas, Emanuel Sanz-Luque, Aurora Galva´ n, and Emilio Ferna´ ndez* Departamento de Bioquı´micay Biologı´aMolecular, Facultad de Ciencias, Universidad de Co´rdoba, Campus de Rabanales, Edif. Severo Ochoa, 14071 Co´rdoba, Spain Edited by Bob B. Buchanan, University of California, Berkeley, CA, and approved October 29, 2007 (received for review May 17, 2007) Molybdenum is an essential element for almost all living beings, In contrast to bacteria, molybdate transporters in eukaryotes which, in the form of a molybdopterin-cofactor, participates in the are unknown, and genes similar to the bacterial molybdate active site of enzymes involved in key reactions of carbon, nitrogen, channel modB have not been found in sequenced eukaryotic and sulfur metabolism. This metal is taken up by cells in form of the genomes. Physiological data from the green alga Chlamydomo- oxyanion molybdate. Bacteria acquire molybdate by an ATP-binding- nas reinhardtii suggest the presence of at least two molybdate cassette (ABC) transport system in a widely studied process, but how transport systems that are related to the unlinked genetic loci Ni5 eukaryotic cells take up molybdenum is unknown because molybdate and Nit6 (10). Mutants defective at one of these loci are transporters have not been identified so far. Here, we report a phenotypically wild type but have a reduced molybdate transport eukaryotic high-affinity molybdate transporter, encoded by the activity; double mutants at both loci lack Moco and, thus, activity green alga Chlamydomonas reinhardtii gene MoT1. An antisense RNA of the molybdoenzyme nitrate reductase (11).
    [Show full text]
  • Toxicity of Sodium Molybdate and Sodium Dichromate to Daphnia Magna Straus Evaluated in Acute, Chronic, and Acetylcholinesterase Inhibition Tests Teresa C
    Ecotoxicology and Environmental Safety 45, 253}259 (2000) Environmental Research, Section B doi:10.1006/eesa.1999.1889, available online at http://www.idealibrary.com on Toxicity of Sodium Molybdate and Sodium Dichromate to Daphnia magna Straus Evaluated in Acute, Chronic, and Acetylcholinesterase Inhibition Tests Teresa C. Diamantino,*,-,1 Lucia Guilhermino,? Elisabete Almeida,- and Amadeu M. V. M. Soares* *Instituto do Ambiente e Vida, Departamento de Zoologia, Largo Marque' s de Pombal, Universidade de Coimbra, 3000 Coimbra, Portugal; -Instituto Nacional de Engenharia e Tecnologia Industrial, Estrada do Pac,o do Lumiar, 1699 Lisboa Codex, Portugal; and ?Instituto de Cie' ncias BimeH dicas de Abel Salazar, Departamento de Estudos de Populac,oJ es, LaboratoH rio de Ecotoxicologia/Centro de Investigac,a8 o Marinha e Ambiental, Universidade do Porto, Lg Prof. Abel Salazar, 2, 4050 Porto, Portugal Received March 18, 1999 spread application in numerous industrial processes, chro- As a result of a widespread application in numerous industrial mium is a contaminant of many environmental systems processes, chromium is a contaminant of many environmental systems. Chromium and their compounds are toxic to both (Cohen et al., 1993). Industrial uses of chromium include invertebrates and vertebrates and, for this reason, there has been metal "nishing industry, production of paints and pigments, a search for suitable and less toxic alternatives. Molybdenum tanning, wood preservation, chromium chemicals produc- compounds have been studied as alternative to chromium tion, pulp and paper production, and metal smelting (Paw- compounds for some industrial applications. The toxicity of lisz et al., 1997). One of the major uses of environmentally chromium is well known but the e4ects of molybdenum and hazardous chemicals is in the metal "nishing industry.
    [Show full text]
  • Removal of Hazardous Oxyanions from the Environment Using Metal-Oxide-Based Materials
    materials Review Removal of Hazardous Oxyanions from the Environment Using Metal-Oxide-Based Materials Ewelina Weidner and Filip Ciesielczyk * Institute of Chemical Technology and Engineering, Faculty of Chemical Technology, Poznan University of Technology, Berdychowo 4, PL-60965 Poznan, Poland; [email protected] * Correspondence: fi[email protected]; Tel.: +48-61-6653626 Received: 11 February 2019; Accepted: 14 March 2019; Published: 20 March 2019 Abstract: Scientific development has increased the awareness of water pollutant forms and has reawakened the need for its effective purification. Oxyanions are created by a variety of redox-sensitive metals and metalloids. These species are harmful to living matter due to their toxicity, nondegradibility, and mobility in aquatic environments. Among a variety of water treatment techniques, adsorption is one of the simplest, cheapest, and most effective. Since metal-oxide-based adsorbents poses a variety of functional groups onto their surface, they were widely applied in ions sorption. In this paper adsorption of harmful oxyanions by metal oxide-based materials according to literature survey was studied. Characteristic of oxyanions originating from As, V, B, W and Mo, their probable adsorption mechanisms and comparison of their sorption affinity for metal-oxide-based materials such as iron oxides, aluminum oxides, titanium dioxide, manganium dioxide, and various oxide minerals and their combinations are presented in this paper. Keywords: oxyanions; sorption; metal oxides; environment pollution; water purification; adsorbents; hazardous metals 1. Introduction Intensive industrial development has contributed to the increased pollution of the environment with hazardous metals and metalloids. The majority of these elements are redox sensitive and some of their oxidation states can form oxyanions in solution.
    [Show full text]
  • Molybdenum, Ferromolybdenum, and Ammonium Molybdate, Phosphoric
    MOLYBDENUM, FERROMOLYBDENUM, AND AMMONIUM MOLYBDATE A. Commodity Summary Almost all molybdenum is recovered from low-grade deposits of the mineral molybdenite, naturally occurring molybdenum disulfide (MoS2), mined either from a primary deposit, or as a byproduct of copper processing.1 In 1993, one mine extracted molybdenum ore, and nine mines recovered molybdenum as a byproduct. Two plants converted molybdenite concentrate to molybdic oxide, which was used to produced ferromolybdenum, metal powder, and other molybdenum compounds.2 Exhibit 1 presents the names and locations of molybdenum mines and processing facilities. EXHIBIT 1 SUMMARY OF MOLYBDENUM, MOLYBDIC OXIDE, AND FERROMOLYBDENUM PRODUCERSa Facility Name Location Cyprus-Climax - Henderson Empire, CO Cyprus-Climax Fort Madison, IA Cyprus-Climax Clear Water, MI Cyprus-Climax - Green Valley Tucson, AZ Cyprus-Climax Baghdad, AZ Kennecott Bingham Canyon, UT Molycorp Inc. Washington, PA Montana Resources Inc. Butte, MT Phelps Dodge Chino, NM San Manuel San Manuel, AZ San Manuel Morenci, AZ Thompson Creek Chalis, ID Thompson Creek Langeloth, PA a - Personal Communication between ICF Incorporated and John W. Blossom, U.S. Bureau of Mines, October 1994. Molybdenum metal is a refractory metal used as an alloying agent in steels, cast irons, and superalloys.3 Ferromolybdenum is an alloy of iron and molybdenum used primarily as an alternative additive in producing alloy steels, cast irons, and nonferrous alloys. The two most common grades of ferromolybdenum are low carbon- and high carbon ferromolybdenum. Ammonium molybdate is an intermediate in manufacturing both molybdenum metal and molybdic oxide, although it can also be sold as a product. Purified MoS2 concentrate also is used as a lubricant.
    [Show full text]
  • Structure of the Molybdate/Tungstate Binding Protein Mop from Sporomusa Ovata
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Structure, Vol. 8, 1127±1136, November, 2000, 2000 Elsevier Science Ltd. All rights reserved. PII S0969-2126(00)00525-6 Structure of the Molybdate/Tungstate Binding Protein Mop from Sporomusa ovata Ulrike G. Wagner,*³ Erhard Stupperich,² sten occur in the environment (typically at low submicromolar ³ 2Ϫ and Christoph Kratky* concentrations) as the soluble oxyanions molybdate (MoO4 ) 2Ϫ *Institut fuÈ r Chemie and tungstate (WO4 ), which have similar sizes, shapes, and Strukturbiologie H bonding properties to those of sulfate, phosphate, and van- Karl-Franzens-UniversitaÈ t adate. A-8010 Graz Bacteria have a high-affinity molybdenum uptake system Austria belonging to the ABC superfamily of transporters [4, 5]. Compo- ² Abteilung Angewandte Mikrobiologie nents of this system include a periplasmic binding protein UniversitaÈ t Ulm (ModA), an integral membrane protein (ModB), and an energizer D-89081 Ulm protein (ModC). The ModA, ModB, and ModC proteins from Germany various organisms (e.g., Escherichia coli, Haemophilus influen- zae, Azotobacter vinelandii, and Rhodobacter capsulatus) are very similar [5]. Molybdate transport is tightly coupled to utiliza- Summary tion in E. coli and Klebsiella pneumoniae, while other organisms appear to have a molybdenum storage protein. In all organisms Background: Transport of molybdenum into bacteria involves studied so far, molybdate transport genes are regulated by a a high-affinity ABC transporter system whose expression is repressor protein, ModE [5]. controlled by a repressor protein called ModE. While molyb- Earlier studies on the accumulation of molybdenum in cells date transport is tightly coupled to utilization in some bacteria, of Clostridium pasteurianum demonstrated that after entry into other organisms have molybdenum storage proteins.
    [Show full text]
  • Oxidative Dehydrogenation of Propane with Cobalt, Tungsten and Molybdenum Based Materials
    Revista Facultad de Ingeniería, Universidad de Antioquia, No. 84, pp. 97-104, 2017 Oxidative dehydrogenation of propane with cobalt, tungsten and molybdenum based materials Deshidrogenación oxidativa de propano con materiales a base de cobalto, tungsteno y molibdeno Maurin Salamanca-Guzmán1, 2*, Yordy Enrique Licea-Fonseca3, Adriana Echavarría-Isaza1, Arnaldo Faro4, Luz Amparo Palacio-Santos5 1 Grupo Catalizadores y Adsorbentes, Instituto de Química, Universidad de Antioquia. Calle 67 # 53-108. A. A. 1226. Medellín, Colombia. 2 Department of Chemistry, Bielefeld University. Universitätsstraße 25, D-33501. Bielefeld, Germany. 3 CENANO-DCAP, Instituto Nacional de Tecnologia. Av. Venezuela 82. CEP 20081-312. Rio de Janeiro, Brasil 4 Departamento de Físico-Química, Instituto de Química, Universidade Federal do Rio de Janeiro. Av. Athos da Silveira Ramos, 149. CEP 21941-909. Río de Janeiro, Brasil. 5 Departamento de Operações e Processos Industriais, Instituto de Química, Universidade do Estado do Rio de Janeiro. Rua São Francisco Xavier, 524. CEP 20550-900. Río de Janeiro, Brasil. ARTICLE INFO ABSTRACT: Oxidative dehydrogenation of propane is a reliable alternative for olefins Received January 20, 2017 production. This paper presents the results obtained on oxidative dehydrogenation of propane Accepted August 09, 2017 by using two materials based on cobalt, tungsten, and molybdenum. The materials were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), temperature programmed reduction (TPR), thermogravimetric analysis (TGA), and differential thermal analysis (DTA). The CoMo y material was calcined at 623 K, transforming itself to β-CoMoO4 phase (CoMo 623), the same phase is observed when the material is calcined at 873 K (CoMo y873).
    [Show full text]
  • UC Berkeley UC Berkeley Previously Published Works
    UC Berkeley UC Berkeley Previously Published Works Title Identifying the Unique Properties of α-Bi2Mo3O12 for the Activation of Propene Permalink https://escholarship.org/uc/item/3z33q49j Journal Journal of Physical Chemistry C, 120(51) ISSN 1932-7447 Authors Licht, RB Getsoian, A Bell, AT Publication Date 2016-12-29 DOI 10.1021/acs.jpcc.6b09949 Peer reviewed eScholarship.org Powered by the California Digital Library University of California Identifying the Unique Properties of α-Bi2Mo3O12 for the Activation of Propene Rachel B. Licht, Andrew “Bean” Getsoian, and Alexis T. Bell* Department of Chemical and Biomolecular Engineering University of California Berkeley, CA 94720-1462 and Chemical Sciences Division Lawrence Berkeley National Laboratory Berkeley, CA 94720 1 Abstract In order to understand the remarkable activity of -Bi2Mo3O12 for selective oxidation and ammoxidation of propene, the propene activation abilityα of four molybdenum-based mixed metal oxides – Bi2Mo3O12, PbMoO4, Bi2Pb5Mo8O32, and MoO3 – was investigated using Density Functional Theory. Propene activation is considered to occur via abstraction of a hydrogen atom from the methyl group of physisorbed propene by lattice oxygen. For each material, the apparent activation energy was estimated by summing the heat of adsorption of propene, the C-H bond dissociation energy, and the hydrogen attachment energy (HAE) for hydrogen addition to lattice oxygen; this sum provides a lower bound for the apparent activation energy. It was found that two structural features of oxide surfaces are essential to achieve low activation barriers: under-coordinated surface cation sites enable strong propene adsorption, and suitable 5- or 6-coordinate geometry at molybdenum result in favorable HAEs.
    [Show full text]
  • The Crystal Chemistry of Novel Thorium and Uranium Compounds with Oxo-Anions from Group VI of Periodic Table (S, Se, Te, Cr, Mo and W)
    The Crystal Chemistry of Novel Thorium and Uranium Compounds with Oxo-Anions from Group VI of Periodic Table (S, Se, Te, Cr, Mo and W) Von der Fakultät für Georessourcen und Materialtechnik der Rheinisch -Westfälischen Technischen Hochschule Aachen Zur Erlangung des akademischen Grades eines Doktors der Naturwissenschaften genehmigte Dissertation Vorgelegt von Magister für Technik und Technologie Bin Xiao aus Sichuan, China Berichter: Prof. Dr. rer.nat. Evgeny V. Alekseev Univ.-Prof. Dr. rer. nat. Georg Roth Univ.-Prof. Dr. rer. nat. Dirk Bosbach Tag der mündlichen Prüfung: 26. Januar 2016 Diese Dissertation ist auf den Internetseiten der Hochschulbibliothek online verfügbar Abstract This dissertation focus on the synthesis, phase studies and physicochemical properties of novel thori- um and uranium compounds with the Group VI (S, Se, Te, Cr, Mo, W) of the Periodic Table. All the studied compounds are listed in Table 2.2 from the page 15. I subdivided all the newly synthesized compounds into several chapters according to their structural and topological differences. First, for thorium molybdates and tungstates, almost all of these compounds are based on corner- sharing of ThOx (x = 6, 8 and 9) and MoO4 or WOx (x = 4, 5, 6) polyhedra. Interestingly, all these compounds can be seen as derived from a pure thorium molybdate compound (ThMo2O8) which was isolated from high-temperature solid-state synthesis method. Therefore, the polymorphs of this most basic ThMo2O8 compound is firstly introduced (see Chapter 3.1 from page 18). The thermodynamic, electronic and vibrational properties of all investigated ThMo2O8 polymorphs were studied using ab initio calculations. Then, two subfamilies of thorium molybdates, that is, rubidium thorium molybdate and cesium thori- um molybdate and their thermal and vibrational behaviors were discussed in details in Chapter 4.1 from page 37 and Chapter 4.2 from page 50, respectively.
    [Show full text]