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Caserta G, Lorent C, Ciaccafava A, Keck M, Breglia R, Greco C, Limberg C, Hildebrandt P, Cramer SP, Zebger I, Lenz O. The large subunit of the regulatory [NiFe]-hydrogenase from Ralstonia eutropha - a minimal hydrogenase? Chem Sci 2020; 11:5453-5465. [PMID: 34094072 PMCID: PMC8159394 DOI: 10.1039/d0sc01369b] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
Chemically synthesized compounds that are capable of facilitating the reversible splitting of dihydrogen into protons and electrons are rare in chemists' portfolio. The corresponding biocatalysts – hydrogenases – are, however, abundant in the microbial world. [NiFe]-hydrogenases represent a major subclass and display a bipartite architecture, composed of a large subunit, hosting the catalytic NiFe(CO)(CN)2 cofactor, and a small subunit whose iron–sulfur clusters are responsible for electron transfer. To analyze in detail the catalytic competence of the large subunit without its smaller counterpart, we purified the large subunit HoxC of the regulatory [NiFe]-hydrogenase of the model H2 oxidizer Ralstonia eutropha to homogeneity. Metal determination and infrared spectroscopy revealed a stoichiometric loading of the metal cofactor. This enabled for the first time the determination of the UV-visible extinction coefficient of the NiFe(CO)(CN)2 cofactor. Moreover, the absence of disturbing iron–sulfur clusters allowed an unbiased look into the low-spin Fe2+ of the active site by Mössbauer spectroscopy. Isolated HoxC was active in catalytic hydrogen–deuterium exchange, demonstrating its capacity to activate H2. Its catalytic activity was drastically lower than that of the bipartite holoenzyme. This was consistent with infrared and electron paramagnetic resonance spectroscopic observations, suggesting that the bridging position between the active site nickel and iron ions is predominantly occupied by water-derived ligands, even under reducing conditions. In fact, the presence of water-derived ligands bound to low-spin Ni2+ was reflected by the absorption bands occurring in the corresponding UV-vis spectra, as revealed by time-dependent density functional theory calculations conducted on appropriate in silico models. Thus, the isolated large subunits indeed represent simple [NiFe]-hydrogenase models, which could serve as blueprints for chemically synthesized mimics. Furthermore, our data point to a fundamental role of the small subunit in preventing water access to the catalytic center, which significantly increases the H2 splitting capacity of the enzyme. Spectroscopic investigation of an isolated [NiFe]-hydrogenase large subunit enables a unique view of the NiFe(CO)(CN)2 cofactor.![]()
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Affiliation(s)
- Giorgio Caserta
- Institut für Chemie, Technische Universität Berlin Straße des 17. Juni 135 10623 Berlin Germany
| | - Christian Lorent
- Institut für Chemie, Technische Universität Berlin Straße des 17. Juni 135 10623 Berlin Germany
| | - Alexandre Ciaccafava
- Institut für Chemie, Technische Universität Berlin Straße des 17. Juni 135 10623 Berlin Germany
| | - Matthias Keck
- Department of Chemistry, Humboldt-Universität zu Berlin Brook-Taylor-Straße 2 12489 Berlin Germany
| | - Raffaella Breglia
- Department of Earth and Environmental Sciences, Milano-Bicocca University Piazza della Scienza 1 20126 Milan Italy
| | - Claudio Greco
- Department of Earth and Environmental Sciences, Milano-Bicocca University Piazza della Scienza 1 20126 Milan Italy
| | - Christian Limberg
- Department of Chemistry, Humboldt-Universität zu Berlin Brook-Taylor-Straße 2 12489 Berlin Germany
| | - Peter Hildebrandt
- Institut für Chemie, Technische Universität Berlin Straße des 17. Juni 135 10623 Berlin Germany
| | | | - Ingo Zebger
- Institut für Chemie, Technische Universität Berlin Straße des 17. Juni 135 10623 Berlin Germany
| | - Oliver Lenz
- Institut für Chemie, Technische Universität Berlin Straße des 17. Juni 135 10623 Berlin Germany
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Hartmann S, Frielingsdorf S, Ciaccafava A, Lorent C, Fritsch J, Siebert E, Priebe J, Haumann M, Zebger I, Lenz O. O2-Tolerant H2 Activation by an Isolated Large Subunit of a [NiFe] Hydrogenase. Biochemistry 2018; 57:5339-5349. [DOI: 10.1021/acs.biochem.8b00760] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sven Hartmann
- Department of Chemistry, Sekr. PC14, Technische Universität Berlin, 10623 Berlin, Germany
| | - Stefan Frielingsdorf
- Department of Chemistry, Sekr. PC14, Technische Universität Berlin, 10623 Berlin, Germany
| | - Alexandre Ciaccafava
- Department of Chemistry, Sekr. PC14, Technische Universität Berlin, 10623 Berlin, Germany
| | - Christian Lorent
- Department of Chemistry, Sekr. PC14, Technische Universität Berlin, 10623 Berlin, Germany
| | - Johannes Fritsch
- Department of Biology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
| | - Elisabeth Siebert
- Department of Chemistry, Sekr. PC14, Technische Universität Berlin, 10623 Berlin, Germany
| | - Jacqueline Priebe
- Department of Chemistry, Sekr. PC14, Technische Universität Berlin, 10623 Berlin, Germany
| | - Michael Haumann
- Department of Physics, Freie Universität Berlin, 14195 Berlin, Germany
| | - Ingo Zebger
- Department of Chemistry, Sekr. PC14, Technische Universität Berlin, 10623 Berlin, Germany
| | - Oliver Lenz
- Department of Chemistry, Sekr. PC14, Technische Universität Berlin, 10623 Berlin, Germany
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Lenz O, Lauterbach L, Frielingsdorf S. O2-tolerant [NiFe]-hydrogenases of Ralstonia eutropha H16: Physiology, molecular biology, purification, and biochemical analysis. Methods Enzymol 2018; 613:117-151. [DOI: 10.1016/bs.mie.2018.10.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
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Saggu M, Zebger I, Ludwig M, Lenz O, Friedrich B, Hildebrandt P, Lendzian F. Spectroscopic insights into the oxygen-tolerant membrane-associated [NiFe] hydrogenase of Ralstonia eutropha H16. J Biol Chem 2009; 284:16264-16276. [PMID: 19304663 DOI: 10.1074/jbc.m805690200] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
This study provides the first spectroscopic characterization of the membrane-bound oxygen-tolerant [NiFe] hydrogenase (MBH) from Ralstonia eutropha H16 in its natural environment, the cytoplasmic membrane. The H2-converting MBH is composed of a large subunit, harboring the [NiFe] active site, and a small subunit, capable in coordinating one [3Fe4S] and two [4Fe4S] clusters. The hydrogenase dimer is electronically connected to a membrane-integral cytochrome b. EPR and Fourier transform infrared spectroscopy revealed a strong similarity of the MBH active site with known [NiFe] centers from strictly anaerobic hydrogenases. Most redox states characteristic for anaerobic [NiFe] hydrogenases were identified except for one remarkable difference. The formation of the oxygen-inhibited Niu-A state was never observed. Furthermore, EPR data showed the presence of an additional paramagnetic center at high redox potential (+290 mV), which couples magnetically to the [3Fe4S] center and indicates a structural and/or redox modification at or near the proximal [4Fe4S] cluster. Additionally, significant differences regarding the magnetic coupling between the Nia-C state and [4Fe4S] clusters were observed in the reduced form of the MBH. The spectroscopic properties are discussed with regard to the unusual oxygen tolerance of this hydrogenase and in comparison with those of the solubilized, dimeric form of the MBH.
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Affiliation(s)
- Miguel Saggu
- From the Institut für Chemie, Technische Universität Berlin, PC14, Strasse des 17. Juni 135, D-10623 Berlin
| | - Ingo Zebger
- From the Institut für Chemie, Technische Universität Berlin, PC14, Strasse des 17. Juni 135, D-10623 Berlin.
| | - Marcus Ludwig
- Institute of Biology, Department of Microbiology, Humboldt-Universität zu Berlin, Chausseestrasse 117, D-10115 Berlin, Germany
| | - Oliver Lenz
- Institute of Biology, Department of Microbiology, Humboldt-Universität zu Berlin, Chausseestrasse 117, D-10115 Berlin, Germany
| | - Bärbel Friedrich
- Institute of Biology, Department of Microbiology, Humboldt-Universität zu Berlin, Chausseestrasse 117, D-10115 Berlin, Germany
| | - Peter Hildebrandt
- From the Institut für Chemie, Technische Universität Berlin, PC14, Strasse des 17. Juni 135, D-10623 Berlin
| | - Friedhelm Lendzian
- From the Institut für Chemie, Technische Universität Berlin, PC14, Strasse des 17. Juni 135, D-10623 Berlin.
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Ludwig M, Cracknell JA, Vincent KA, Armstrong FA, Lenz O. Oxygen-tolerant H2 oxidation by membrane-bound [NiFe] hydrogenases of ralstonia species. Coping with low level H2 in air. J Biol Chem 2008; 284:465-477. [PMID: 18990688 DOI: 10.1074/jbc.m803676200] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Knallgas bacteria such as certain Ralstonia spp. are able to obtain metabolic energy by oxidizing trace levels of H2 using O2 as the terminal electron acceptor. The [NiFe] hydrogenases produced by these organisms are unusual in their ability to oxidize H2 in the presence of O2, which is a potent inactivator of most hydrogenases through attack at the active site. To probe the origin of this unusual O2 tolerance, we conducted a study on the membrane-bound hydrogenase from Ralstonia eutropha H16 and that of the closely related organism Ralstonia metallidurans CH34, which was purified using a new heterologous overproduction system. Direct electrochemical methods were used to determine apparent inhibition constants for O2 inhibition of H2 oxidation (K I(app)O2) for each enzyme. These values were at least 2 orders of magnitude higher than those of "standard" [NiFe] hydrogenases. Amino acids close to the active site were exchanged in the membrane-bound hydrogenase of R. eutropha H16 for those from standard hydrogenases to probe the role of individual residues in conferring O2 sensitivity. Michaelis constants for H2 (K M H2) were determined, and for some mutants these were increased more than 20-fold relative to the wild type. Mutations resulting in membrane-bound hydrogenase enzymes with increased K M H2 or decreased K I(app)O2 values were associated with impaired lithoautotrophic growth in the presence of high O2 concentrations.
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Affiliation(s)
- Marcus Ludwig
- Institut fu¨r Biologie/Mikrobiologie, Humboldt-Universita¨t zu Berlin, Chausseestrasse 117, 10115 Berlin, Germany and the Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom
| | - James A Cracknell
- Institut fu¨r Biologie/Mikrobiologie, Humboldt-Universita¨t zu Berlin, Chausseestrasse 117, 10115 Berlin, Germany and the Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Kylie A Vincent
- Institut fu¨r Biologie/Mikrobiologie, Humboldt-Universita¨t zu Berlin, Chausseestrasse 117, 10115 Berlin, Germany and the Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Fraser A Armstrong
- Institut fu¨r Biologie/Mikrobiologie, Humboldt-Universita¨t zu Berlin, Chausseestrasse 117, 10115 Berlin, Germany and the Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Oliver Lenz
- Institut fu¨r Biologie/Mikrobiologie, Humboldt-Universita¨t zu Berlin, Chausseestrasse 117, 10115 Berlin, Germany and the Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom.
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Schubert T, Lenz O, Krause E, Volkmer R, Friedrich B. Chaperones specific for the membrane-bound [NiFe]-hydrogenase interact with the Tat signal peptide of the small subunit precursor in Ralstonia eutropha H16. Mol Microbiol 2007; 66:453-67. [PMID: 17850259 DOI: 10.1111/j.1365-2958.2007.05933.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Periplasmic membrane-bound [NiFe]-hydrogenases undergo a complex maturation pathway, including cofactor incorporation, subunit assembly, and finally twin-arginine-dependent membrane translocation (Tat). In this study, the role of the two accessory proteins HoxO and HoxQ in the maturation of the membrane-bound [NiFe]-hydrogenase (MBH) of Ralstonia eutropha H16 was investigated. MBH activity was absent in soluble as well as membrane fractions of cells with deletions in the respective genes. The absence of HoxO and HoxQ led to degradation of the small subunit precursor (preHoxK) of the MBH. The two accessory proteins directly interacted with preHoxK prior to assembly of active MBH dimer in the cytoplasm. MBH mutants with modified Tat signal peptides were disrupted in preHoxK/HoxO/HoxQ complex formation. Isolated HoxO and HoxQ proteins formed a complex in vitro with the chemically synthesized HoxK Tat signal peptide. Two functions of the two chaperones are discussed: (i) protection of the Fe-S cluster containing HoxK subunit under oxygenic conditions, and (ii) avoidance of HoxK export prior to dimerization with the large MBH subunit HoxG.
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Affiliation(s)
- Torsten Schubert
- Institut für Biologie, Humboldt-Universität zu Berlin, Chausseestr. 117, D-10115 Berlin, Germany
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Kutty R, Bennett GN. Studies on inhibition of transformation of 2,4,6-trinitrotoluene catalyzed by Fe-only hydrogenase from Clostridium acetobutylicum. J Ind Microbiol Biotechnol 2006; 33:368-76. [PMID: 16550436 DOI: 10.1007/s10295-005-0067-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2005] [Accepted: 12/03/2005] [Indexed: 10/25/2022]
Abstract
The major enzyme in Clostridium acetobutylicum ATCC 824 leading to transformation of TNT has been reported to be the Fe-only hydrogenase. In this study, we examine the effect of inhibitors of hydrogenase on TNT reduction by Clostridial extracts. These experiments further demonstrate the major role of hydrogenase in TNT transformation. The C. acetobutylicum hydrogenase is closely related to that of C. pasteurianum; and can be fitted to the X-ray crystal structure with a root mean square deviation of 1.18 angstroms for the Calpha atoms of the generated 3D simulation model. The Hyd1, Hyd2, and Hyd3 antibodies generated against hydrogenase reacted with both the hydrogenase in cell extracts and with C. acetobutylicum hydrogenase expressed in Escherichia coli. Inhibition studies using antibodies against Fe-only hydrogenase from C. acetobutylicum indicated that the transformation of TNT by crude cell extracts was completely inhibited by Hyd2 antibody (to amino acid 415-428) whereas antibodies Hyd1 (to residues 1-16) and Hyd3 (to amino acid 424-448) inhibited less effectively. The TNT transforming activity of the cell extract was retained when Hyd2 antibody pretreated with purified but enzymatically inactive recombinant hydrogenase was added to the extract. Addition of the transition metal Cu2+ to extracts completely inhibited the transformation of TNT suggesting the destruction of [4Fe-4S] centers which are essential for transfer of electrons from the H2-activating site to TNT. Growth of C. acetobutylicum was also inhibited by 0.5 mM Cu2+ and Hg2+ ions. The triazine dye, procion red and the nitroimidazole drug, metronidazole inhibit TNT reduction. The inhibition studies using antibodies, procion red, metronidazole, and transition metals suggest that different portions of hydrogenase are required for effective TNT reduction.
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Affiliation(s)
- Razia Kutty
- Department of Biochemistry and Cell Biology MS-140, Rice University, Houston, TX 77005-1892, USA
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8
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Bernhard M, Friedrich B, Siddiqui RA. Ralstonia eutropha TF93 is blocked in tat-mediated protein export. J Bacteriol 2000; 182:581-8. [PMID: 10633089 PMCID: PMC94318 DOI: 10.1128/jb.182.3.581-588.2000] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/1999] [Accepted: 11/08/1999] [Indexed: 11/20/2022] Open
Abstract
Ralstonia eutropha (formerly Alcaligenes eutrophus) TF93 is pleiotropically affected in the translocation of redox enzymes synthesized with an N-terminal signal peptide bearing a twin arginine (S/T-R-R-X-F-L-K) motif. Immunoblot analyses showed that the catalytic subunits of the membrane-bound [NiFe] hydrogenase (MBH) and the molybdenum cofactor-binding periplasmic nitrate reductase (Nap) are mislocalized to the cytoplasm and to the inner membrane, respectively. Moreover, physiological studies showed that the copper-containing nitrous oxide reductase (NosZ) was also not translocated to the periplasm in strain TF93. The cellular localization of enzymes exported by the general secretion system was unaffected. The translocation-arrested MBH and Nap proteins were enzymatically active, suggesting that twin-arginine signal peptide-dependent redox enzymes may have their cofactors inserted prior to transmembrane export. The periplasmic destination of MBH, Nap, and NosZ was restored by heterologous expression of Azotobacter chroococcum tatA mobilized into TF93. tatA encodes a bacterial Hcf106-like protein, a component of a novel protein transport system that has been characterized in thylakoids and shown to translocate folded proteins across the membrane.
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Affiliation(s)
- M Bernhard
- Institut für Biologie, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
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9
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Hoppert M, Braks I, Mayer F. Stability and activity of hydrogenases of Methanobacterium thermoautotrophicum and Alcaligenes eutrophus in reversed micellar systems. FEMS Microbiol Lett 1994; 118:249-54. [PMID: 8020749 DOI: 10.1111/j.1574-6968.1994.tb06836.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
In water-in-oil microemulsion the membrane-associated F420-hydrogenase of Methanobacterium thermoautotrophicum (strain Marburg) and the membrane-bound hydrogenase of Alcaligenes eutrophus H 16 (MBH) showed prolonged activity at elevated temperatures (measured as hydrogen production) as compared to aqueous buffer solution. The temperature optimum of the reactions was about 15 degrees C higher than in aqueous buffer solution. Activity of the almost completely inactivated F420-hydrogenase could be partially recovered by transfer into microemulsion.
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Affiliation(s)
- M Hoppert
- Institut für Mikrobiologie, Georg-August-Universität Göttingen, FRG
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Sánchez-Ferrer A, Bru R, García-Carmona F. Phase separation of biomolecules in polyoxyethylene glycol nonionic detergents. Crit Rev Biochem Mol Biol 1994; 29:275-313. [PMID: 8001397 DOI: 10.3109/10409239409083483] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The advantage of aqueous two-phase systems based on polyoxyethylene detergents over other liquid-liquid two-phase systems lies in their capacity to fractionate membrane proteins simply by heating the solution over a biocompatible range of temperatures (20 to 37 degrees C). This permits the peripheral membrane proteins to be effectively separated from the integral membrane proteins, which remain in the detergent-rich phase due to the interaction of their hydrophobic domains with detergent micelles. Since the first reports of this special characteristic of polyoxyethylene glycol detergents in 1981, numerous reports have consolidated this procedure as a fundamental technique in membrane biochemistry and molecular biology. As examples of their use in these two fields, this review summarizes the studies carried out on the topology, diversity, and anomalous behavior of transmembrane proteins on the distribution of glycosyl-phosphatidylinositol-anchored membrane proteins, and on a mechanism to describe the pH-induced translocation of viruses, bacterial endotoxins, and soluble cytoplasmic proteins related to membrane fusion. In addition, the phase separation capacity of these polyoxyethylene glycol detergents has been used to develop quick fractionation methods with high recoveries, on both a micro- and macroscale, and to speed up or increase the efficiency of bioanalytical assays.
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Affiliation(s)
- A Sánchez-Ferrer
- Departamento de Bioquímica y Biología Molecular-A, Facultad de Biología, Universidad de Murcia, Spain
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Cantet J, Bergel A, Comtat M, Séris JL. Kinetics of the catalysis by the Alcaligenes eutrophus H16 hydrogenase of the electrochemical reduction of NAD+. ACTA ACUST UNITED AC 1992. [DOI: 10.1016/0304-5102(92)80088-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Dross F, Geisler V, Lenger R, Theis F, Krafft T, Fahrenholz F, Kojro E, Duchêne A, Tripier D, Juvenal K. The quinone-reactive Ni/Fe-hydrogenase of Wolinella succinogenes. EUROPEAN JOURNAL OF BIOCHEMISTRY 1992; 206:93-102. [PMID: 1587288 DOI: 10.1111/j.1432-1033.1992.tb16905.x] [Citation(s) in RCA: 110] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The hydrogenase (Hyd) isolated from the cytoplasmic membrane of Wolinella succinogenes consists of three polypeptides (HydA, HydB and HydC) and contains cytochrome b (6.4 mumol/g protein), which was reduced upon the addition of H2. The enzyme catalyzed the reduction of 2,3-dimethyl-1,4-naphthoquinone with H2, in contrast to an earlier preparation which was made up of HydA and HydB only and did not contain cytochrome b (Unden, G., Böcher, R., Knecht, J. & Kröger, A. (1982) FEBS Lett. 145, 230-234). This suggests that HydC is a cytochrome b which serves as a mediator in the electron transfer from H2 to the quinone. The hydrogenase genes were cloned, sequenced and identified by sequence comparison with the N-termini of the three subunits. The three genes were arranged in the order hydA, hydB, hydC, with the transcription start site in front of hydA, and were present only once on the genome. Separated by an intergene region of 69 nucleotides, hydC was followed by at least two more open reading frames of unknown function. The amino acid sequences derived from hydA, hydB and hydC were similar to those of the membrane Ni-hydrogenases of seven other bacteria. HydA and HydB also showed similarity to the small and the large subunits of periplasmic Ni-hydrogenases. HydC was predicted to contain four hydrophobic segments which might span the bacterial membrane. Two histidine residues located in hydrophobic segments are conserved in the corresponding sequences of the other membrane hydrogenases and might ligate the haem B.
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Affiliation(s)
- F Dross
- Institut für Mikrobiologie, J. W. Goethe-Universität, Frankfurt, Federal Republic of Germany
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Lorenz B, Schneider K, Kratzin H, Schlegel HG. Immunological comparison of subunits isolated from various hydrogenases of aerobic hydrogen bacteria. BIOCHIMICA ET BIOPHYSICA ACTA 1989; 995:1-9. [PMID: 2493816 DOI: 10.1016/0167-4838(89)90225-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Polyclonal, monospecific antibodies were produced against the two subunits (Mr 62,000, and Mr 31,000), isolated from the membrane-bound hydrogenase of Alcaligenes eutrophus H16. The antibodies (IgG fractions) were purified from crude sera by Protein A-Sepharose CL-4B chromatography. By double immunodiffusion assays and tandem-crossed immunoelectrophoresis the large and the small subunit were demonstrated not to be immunologically related. Immunological comparison of these subunits with the four non-identical subunits (Mr 63,000, 56,000, 30,000 and 26,000) of the NAD-linked, soluble hydrogenase from A. eutrophus H16 showed that the subunits of the membrane-bound hydrogenase did not cross-react with any of the antibodies raised against the four subunits of the NAD-linked enzyme and that, vice versa, none of these four subunits cross-reacted with antibodies raised against the two subunits of the membrane-bound hydrogenase. This means that A. eutrophus H16 contains altogether six non-identical immunologically unrelated hydrogenase polypeptides. The membrane-bound hydrogenases were isolated and purified from various aerobic H2-oxidizing bacteria: A. eutrophus H16, A. eutrophus type strain, A. eutrophus CH34, A. eutrophus Z1, A. hydrogenophilus, Paracoccus denitrificans and strain Cd2/01. All these proteins resembled each other and each consisted of two non-identical polypeptides. A complete separation of these subunits was achieved at high-yield by preparative FPLC gel filtration on three Superose 12 columns connected in series, using SDS and DTT-containing sodium phosphate buffer (pH 7.0). The small subunits of these enzymes turned out to be immunologically closely related to each other; they were either identical or almost identical. The large subunits were also related, but less pronounced. Only the large subunits from Z1 and type strain reacted fully identical with the H16 subunit. Of the two isolated, homogeneous subunits of the membrane-bound hydrogenase from A. eutrophus H16, the amino acid compositions and the NH2-terminal sequences have been determined. The results confirmed the diversity of the large and the small subunit. Furthermore, for comparison also the NH2-terminal sequences of the two subunits from the hydrogenase of A. eutrophus CH34 have been analysed.
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Affiliation(s)
- B Lorenz
- Institut für Mikrobiologie, Universität Göttingen, F.R.G
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Knüttel K, Schneider K, Schlegel HG, Müller A. The membrane-bound hydrogenase from Paracoccus denitrificans. Purification and molecular characterization. EUROPEAN JOURNAL OF BIOCHEMISTRY 1989; 179:101-8. [PMID: 2537196 DOI: 10.1111/j.1432-1033.1989.tb14526.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The membrane-bound hydrogenase from Paracoccus denitrificans was purified 68-fold with a yield of 14.6%. The final preparation had a specific activity of 161.9 mumol H2 min-1 (mg protein)-1 (methylene blue reduction). Purification involved solubilization by Triton X-114, phase separation, chromatography on DEAE-Sephacel, ammonium-sulfate precipitation and chromatography on Procion-red HE-3B-Sepharose. Gel electrophoresis under denaturing conditions revealed two non-identical subunits with molecular masses of 64 kDa and 34 kDa. The molecular mass of the native enzyme was 100 kDa, as estimated by FPLC gel filtration in the presence of Chaps, a zwitterionic detergent. The isoelectric point of the Paracoccus hydrogenase was 4.3. Metal analysis of the purified enzyme indicated a content of 0.6 nickel and 7.3 iron atoms/molecule. ESR spectra of the reduced enzyme exhibited a close similarity to the membrane-bound hydrogenase from Alcaligenes eutrophus H16 with g values of 1.86, 1.92 and 1.98. The half-life for inactivation under air at 20 degrees C was 8 h. The Paracoccus hydrogenase reduced several electron acceptors, namely methylene blue, benzyl viologen, methyl viologen, menadione, cytochrome c, FMN, 2,6-dichloroindophenol, ferricyanide and phenazine methosulfate. The highest activity was measured with methylene blue (V = 161.9 U/mg; Km = 0.04 mM), whereas benzyl and methyl viologen were reduced at distinctly lower rates (16.5 U/mg and 12.1 U/mg, respectively). The native hydrogenase from P. denitrificans cross-reacted with purified antibodies raised against the membrane-bound hydrogenase from A. eutrophus H16. The corresponding subunits from both enzymes also showed immunological relationship. All reactions were of partial identity.
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Affiliation(s)
- K Knüttel
- Institut für Mikrobiologie der Universität Göttingen, Federal Republic of Germany
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