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Parson WW, Huang J, Kulke M, Vermaas JV, Kramer DM. Electron transfer in a crystalline cytochrome with four hemes. J Chem Phys 2024; 160:065101. [PMID: 38341797 DOI: 10.1063/5.0186958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 01/18/2024] [Indexed: 02/13/2024] Open
Abstract
Diffusion of electrons over distances on the order of 100 μm has been observed in crystals of a small tetraheme cytochrome (STC) from Shewanella oneidensis [J. Huang et al. J. Am. Chem. Soc. 142, 10459-10467 (2020)]. Electron transfer between hemes in adjacent subunits of the crystal is slower and more strongly dependent on temperature than had been expected based on semiclassical electron-transfer theory. We here explore explanations for these findings by molecular-dynamics simulations of crystalline and monomeric STC. New procedures are developed for including time-dependent quantum mechanical energy differences in the gap between the energies of the reactant and product states and for evaluating fluctuations of the electronic-interaction matrix element that couples the two hemes. Rate constants for electron transfer are calculated from the time- and temperature-dependent energy gaps, coupling factors, and Franck-Condon-weighted densities of states using an expression with no freely adjustable parameters. Back reactions are considered, as are the effects of various protonation states of the carboxyl groups on the heme side chains. Interactions with water are found to dominate the fluctuations of the energy gap between the reactant and product states. The calculated rate constant for electron transfer from heme IV to heme Ib in a neighboring subunit at 300 K agrees well with the measured value. However, the calculated activation energy of the reaction in the crystal is considerably smaller than observed. We suggest two possible explanations for this discrepancy. The calculated rate constant for transfer from heme I to II within the same subunit of the crystal is about one-third that for monomeric STC in solution.
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Affiliation(s)
- William W Parson
- Department of Biochemistry, University of Washington, Seattle, Washington 98195, USA
| | - Jingcheng Huang
- DOE-Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA
| | - Martin Kulke
- DOE-Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA
| | - Josh V Vermaas
- DOE-Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA
| | - David M Kramer
- DOE-Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA
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2
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Ford KC, TerAvest MA. The electron transport chain of Shewanella oneidensis MR-1 can operate bidirectionally to enable microbial electrosynthesis. Appl Environ Microbiol 2024; 90:e0138723. [PMID: 38117056 PMCID: PMC10807441 DOI: 10.1128/aem.01387-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 11/13/2023] [Indexed: 12/21/2023] Open
Abstract
Extracellular electron transfer is a process by which bacterial cells can exchange electrons with a redox-active material located outside of the cell. In Shewanella oneidensis, this process is natively used to facilitate respiration using extracellular electron acceptors such as Fe(III) or an anode. Previously, it was demonstrated that this process can be used to drive the microbial electrosynthesis (MES) of 2,3-butanediol (2,3-BDO) in S. oneidensis exogenously expressing butanediol dehydrogenase (BDH). Electrons taken into the cell from a cathode are used to generate NADH, which in turn is used to reduce acetoin to 2,3-BDO via BDH. However, generating NADH via electron uptake from a cathode is energetically unfavorable, so NADH dehydrogenases couple the reaction to proton motive force. We therefore need to maintain the proton gradient across the membrane to sustain NADH production. This work explores accomplishing this task by bidirectional electron transfer, where electrons provided by the cathode go to both NADH formation and oxygen (O2) reduction by oxidases. We show that oxidases use trace dissolved oxygen in a microaerobic bioelectrical chemical system (BES), and the translocation of protons across the membrane during O2 reduction supports 2,3-BDO generation. Interestingly, this process is inhibited by high levels of dissolved oxygen in this system. In an aerated BES, O2 molecules react with the strong reductant (cathode) to form reactive oxygen species, resulting in cell death.IMPORTANCEMicrobial electrosynthesis (MES) is increasingly employed for the generation of specialty chemicals, such as biofuels, bioplastics, and cancer therapeutics. For these systems to be viable for industrial scale-up, it is important to understand the energetic requirements of the bacteria to mitigate unnecessary costs. This work demonstrates sustained production of an industrially relevant chemical driven by a cathode. Additionally, it optimizes a previously published system by removing any requirement for phototrophic energy, thereby removing the additional cost of providing a light source. We also demonstrate the severe impact of oxygen intrusion into bioelectrochemical systems, offering insight to future researchers aiming to work in an anaerobic environment. These studies provide insight into both the thermodynamics of electrosynthesis and the importance of the bioelectrochemical systems' design.
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Affiliation(s)
- Kathryne C. Ford
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Michaela A. TerAvest
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
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3
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Kulke M, Olson DM, Huang J, Kramer DM, Vermaas JV. Long-Range Electron Transport Rates Depend on Wire Dimensions in Cytochrome Nanowires. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2304013. [PMID: 37653599 DOI: 10.1002/smll.202304013] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 08/18/2023] [Indexed: 09/02/2023]
Abstract
The ability to redirect electron transport to new reactions in living systems opens possibilities to store energy, generate new products, or probe physiological processes. Recent work by Huang et al. showed that 3D crystals of small tetraheme cytochromes (STC) can transport electrons over nanoscopic to mesoscopic distances by an electron hopping mechanism, making them promising materials for nanowires. However, fluctuations at room temperature may distort the nanostructure, hindering efficient electron transport. Classical molecular dynamics simulations of these fluctuations at the nano- and mesoscopic scales allowed us to develop a graph network representation to estimate maximum electron flow that can be driven through STC wires. In longer nanowires, transient structural fluctuations at protein-protein interfaces tended to obstruct efficient electron transfer, but these blockages are ameliorated in thicker crystals where alternative electron transfer pathways become more efficient. The model implies that more flexible proteinprotein interfaces limit the required minimum diameter to carry currents commensurate with conventional electronics.
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Affiliation(s)
- Martin Kulke
- MSU-DOE Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, 612 Wilson Rd, East Lansing, MI, 48824, United States of America
| | - Dayna M Olson
- MSU-DOE Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, 612 Wilson Rd, East Lansing, MI, 48824, United States of America
| | - Jingcheng Huang
- MSU-DOE Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, 612 Wilson Rd, East Lansing, MI, 48824, United States of America
| | - David M Kramer
- MSU-DOE Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, 612 Wilson Rd, East Lansing, MI, 48824, United States of America
| | - Josh V Vermaas
- MSU-DOE Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, 612 Wilson Rd, East Lansing, MI, 48824, United States of America
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4
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Terai K, Yuly JL, Zhang P, Beratan DN. Correlated particle transport enables biological free energy transduction. Biophys J 2023; 122:1762-1771. [PMID: 37056051 PMCID: PMC10209040 DOI: 10.1016/j.bpj.2023.04.009] [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: 12/21/2022] [Revised: 02/17/2023] [Accepted: 04/07/2023] [Indexed: 04/15/2023] Open
Abstract
Studies of biological transport frequently neglect the explicit statistical correlations among particle site occupancies (i.e., they use a mean-field approximation). Neglecting correlations sometimes captures biological function, even for out-of-equilibrium and interacting systems. We show that neglecting correlations fails to describe free energy transduction, mistakenly predicting an abundance of slippage and energy dissipation, even for networks that are near reversible and lack interactions among particle sites. Interestingly, linear charge transport chains are well described without including correlations, even for networks that are driven and include site-site interactions typical of biological electron transfer chains. We examine three specific bioenergetic networks: a linear electron transfer chain (as found in bacterial nanowires), a near-reversible electron bifurcation network (as in complex III of respiration and other recently discovered structures), and a redox-coupled proton pump (as in complex IV of respiration).
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Affiliation(s)
- Kiriko Terai
- Department of Chemistry, Duke University, Durham, North Carolina
| | - Jonathon L Yuly
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersy
| | - Peng Zhang
- Department of Chemistry, Duke University, Durham, North Carolina
| | - David N Beratan
- Department of Chemistry, Duke University, Durham, North Carolina; Department of Physics, Duke University, Durham, North Carolina; Department of Biochemistry, Duke University, Durham, North Carolina.
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5
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Silva MA, Fernandes AP, Turner DL, Salgueiro CA. A Biochemical Deconstruction-Based Strategy to Assist the Characterization of Bacterial Electric Conductive Filaments. Int J Mol Sci 2023; 24:ijms24087032. [PMID: 37108196 PMCID: PMC10138318 DOI: 10.3390/ijms24087032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/28/2023] [Accepted: 04/04/2023] [Indexed: 04/29/2023] Open
Abstract
Periplasmic nanowires and electric conductive filaments made of the polymeric assembly of c-type cytochromes from Geobacter sulfurreducens bacterium are crucial for electron storage and/or extracellular electron transfer. The elucidation of the redox properties of each heme is fundamental to the understanding of the electron transfer mechanisms in these systems, which first requires the specific assignment of the heme NMR signals. The high number of hemes and the molecular weight of the nanowires dramatically decrease the spectral resolution and make this assignment extremely complex or unattainable. The nanowire cytochrome GSU1996 (~42 kDa) is composed of four domains (A to D) each containing three c-type heme groups. In this work, the individual domains (A to D), bi-domains (AB, CD) and full-length nanowire were separately produced at natural abundance. Sufficient protein expression was obtained for domains C (~11 kDa/three hemes) and D (~10 kDa/three hemes), as well as for bi-domain CD (~21 kDa/six hemes). Using 2D-NMR experiments, the assignment of the heme proton NMR signals for domains C and D was obtained and then used to guide the assignment of the corresponding signals in the hexaheme bi-domain CD. This new biochemical deconstruction-based procedure, using nanowire GSU1996 as a model, establishes a new strategy to functionally characterize large multiheme cytochromes.
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Affiliation(s)
- Marta A Silva
- Associate Laboratory, i4HB-Institute for Health and Bioeconomy, School of Science and Technology, NOVA University Lisbon, 2819-516 Caparica, Portugal
- UCIBIO-Applied Molecular Biosciences Unit, Chemistry Department, School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, Portugal
| | - Ana P Fernandes
- Associate Laboratory, i4HB-Institute for Health and Bioeconomy, School of Science and Technology, NOVA University Lisbon, 2819-516 Caparica, Portugal
- UCIBIO-Applied Molecular Biosciences Unit, Chemistry Department, School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, Portugal
| | - David L Turner
- Instituto de Tecnologia Química e Biológica António Xavier, NOVA University Lisbon, 2780-157 Oeiras, Portugal
| | - Carlos A Salgueiro
- Associate Laboratory, i4HB-Institute for Health and Bioeconomy, School of Science and Technology, NOVA University Lisbon, 2819-516 Caparica, Portugal
- UCIBIO-Applied Molecular Biosciences Unit, Chemistry Department, School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, Portugal
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6
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Gemünde A, Lai B, Pause L, Krömer J, Holtmann D. Redox mediators in microbial electrochemical systems. ChemElectroChem 2022. [DOI: 10.1002/celc.202200216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- André Gemünde
- Technische Hochschule Mittelhessen Institute of Bioprocess Engineering and Pharmaceutical Technology Wiesenstraße 14 35390 Gießen GERMANY
| | - Bin Lai
- Helmholtz Centre for Environmental Research UFZ Department of Environmental Microbiology: Helmholtz-Zentrum fur Umweltforschung UFZ Abteilung Umweltmikrobiologie Systems Biotechnology 04318 Leipzig GERMANY
| | - Laura Pause
- Helmholtz Centre for Environmental Research UFZ Environmental Engineering and Biotechnology Research Unit: Helmholtz-Zentrum fur Umweltforschung UFZ Themenbereich Umwelt- und Biotechnologie Systems Biotechnology 04318 Leipzig GERMANY
| | - Jens Krömer
- Helmholtz Centre for Environmental Research UFZ Environmental Engineering and Biotechnology Research Unit: Helmholtz-Zentrum fur Umweltforschung UFZ Themenbereich Umwelt- und Biotechnologie Systems Biotechnology 04318 Leipzig GERMANY
| | - Dirk Holtmann
- Technische Hochschule Mittelhessen IBPT Wiesenstrasse 14 35390 Giessen GERMANY
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7
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Jiang V, Khare SD, Banta S. Computational structure prediction provides a plausible mechanism for electron transfer by the outer membrane protein Cyc2 from Acidithiobacillus ferrooxidans. Protein Sci 2021; 30:1640-1652. [PMID: 33969560 DOI: 10.1002/pro.4106] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/30/2021] [Accepted: 05/03/2021] [Indexed: 12/14/2022]
Abstract
Cyc2 is the key protein in the outer membrane of Acidithiobacillus ferrooxidans that mediates electron transfer between extracellular inorganic iron and the intracellular central metabolism. This cytochrome c is specific for iron and interacts with periplasmic proteins to complete a reversible electron transport chain. A structure of Cyc2 has not yet been characterized experimentally. Here we describe a structural model of Cyc2, and associated proteins, to highlight a plausible mechanism for the ferrous iron electron transfer chain. A comparative modeling protocol specific for trans membrane beta barrel (TMBB) proteins in acidophilic conditions (pH ~ 2) was applied to the primary sequence of Cyc2. The proposed structure has three main regimes: Extracellular loops exposed to low-pH conditions, a TMBB, and an N-terminal cytochrome-like region within the periplasmic space. The Cyc2 model was further refined by identifying likely iron and heme docking sites. This represents the first computational model of Cyc2 that accounts for the membrane microenvironment and the acidity in the extracellular matrix. This approach can be used to model other TMBBs which can be critical for chemolithotrophic microbial growth.
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Affiliation(s)
- Virginia Jiang
- Department of Chemical Engineering, Columbia University in the City of New York, New York, New York, USA
| | - Sagar D Khare
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
| | - Scott Banta
- Department of Chemical Engineering, Columbia University in the City of New York, New York, New York, USA
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8
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Huang J, Zarzycki J, Gunner MR, Parson WW, Kern JF, Yano J, Ducat DC, Kramer DM. Mesoscopic to Macroscopic Electron Transfer by Hopping in a Crystal Network of Cytochromes. J Am Chem Soc 2020; 142:10459-10467. [DOI: 10.1021/jacs.0c02729] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Jingcheng Huang
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, United States
| | - Jan Zarzycki
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, United States
| | - M. R. Gunner
- Department of Physics, City College of New York, New York, New York 10031, United States
| | - William W. Parson
- Department of Biochemistry, University of Washington, Seattle, Washington 98195, United States
| | - Jan F. Kern
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Junko Yano
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Daniel C. Ducat
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, United States
| | - David M. Kramer
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, United States
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9
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The Crystal Structure of a Biological Insulated Transmembrane Molecular Wire. Cell 2020; 181:665-673.e10. [PMID: 32289252 PMCID: PMC7198977 DOI: 10.1016/j.cell.2020.03.032] [Citation(s) in RCA: 100] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 12/18/2019] [Accepted: 03/13/2020] [Indexed: 01/15/2023]
Abstract
A growing number of bacteria are recognized to conduct electrons across their cell envelope, and yet molecular details of the mechanisms supporting this process remain unknown. Here, we report the atomic structure of an outer membrane spanning protein complex, MtrAB, that is representative of a protein family known to transport electrons between the interior and exterior environments of phylogenetically and metabolically diverse microorganisms. The structure is revealed as a naturally insulated biomolecular wire possessing a 10-heme cytochrome, MtrA, insulated from the membrane lipidic environment by embedding within a 26 strand β-barrel formed by MtrB. MtrAB forms an intimate connection with an extracellular 10-heme cytochrome, MtrC, which presents its hemes across a large surface area for electrical contact with extracellular redox partners, including transition metals and electrodes. The 20 hemes of a 3-component complex are arranged to move electrons across 185 Å A β-barrel and 10-heme cytochrome form an insulated transmembrane nanowire An extracellular 10-heme cytochrome has a large surface area for electron exchange The hemes of both cytochromes are packed with a maximum inter-heme distance of 8 Å
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10
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Light SH, Méheust R, Ferrell JL, Cho J, Deng D, Agostoni M, Iavarone AT, Banfield JF, D’Orazio SEF, Portnoy DA. Extracellular electron transfer powers flavinylated extracellular reductases in Gram-positive bacteria. Proc Natl Acad Sci U S A 2019; 116:26892-26899. [PMID: 31818955 PMCID: PMC6936397 DOI: 10.1073/pnas.1915678116] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mineral-respiring bacteria use a process called extracellular electron transfer to route their respiratory electron transport chain to insoluble electron acceptors on the exterior of the cell. We recently characterized a flavin-based extracellular electron transfer system that is present in the foodborne pathogen Listeria monocytogenes, as well as many other Gram-positive bacteria, and which highlights a more generalized role for extracellular electron transfer in microbial metabolism. Here we identify a family of putative extracellular reductases that possess a conserved posttranslational flavinylation modification. Phylogenetic analyses suggest that divergent flavinylated extracellular reductase subfamilies possess distinct and often unidentified substrate specificities. We show that flavinylation of a member of the fumarate reductase subfamily allows this enzyme to receive electrons from the extracellular electron transfer system and support L. monocytogenes growth. We demonstrate that this represents a generalizable mechanism by finding that a L. monocytogenes strain engineered to express a flavinylated extracellular urocanate reductase uses urocanate by a related mechanism and to a similar effect. These studies thus identify an enzyme family that exploits a modular flavin-based electron transfer strategy to reduce distinct extracellular substrates and support a multifunctional view of the role of extracellular electron transfer activities in microbial physiology.
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Affiliation(s)
- Samuel H. Light
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720
| | - Raphaël Méheust
- Department of Earth and Planetary Science, University of California, Berkeley, CA 94720
- Innovative Genomics Institute, Berkeley, CA 94704
| | - Jessica L. Ferrell
- Department of Microbiology, Immunology & Molecular Genetics, University of Kentucky, Lexington, KY 40536-0298
| | - Jooyoung Cho
- Department of Microbiology, Immunology & Molecular Genetics, University of Kentucky, Lexington, KY 40536-0298
| | - David Deng
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720
| | - Marco Agostoni
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, CA 94720
| | - Anthony T. Iavarone
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, CA 94720
- QB3/Chemistry Mass Spectrometry Facility, University of California, Berkeley, CA 94720
| | - Jillian F. Banfield
- Department of Earth and Planetary Science, University of California, Berkeley, CA 94720
- Innovative Genomics Institute, Berkeley, CA 94704
| | - Sarah E. F. D’Orazio
- Department of Microbiology, Immunology & Molecular Genetics, University of Kentucky, Lexington, KY 40536-0298
| | - Daniel A. Portnoy
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720
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11
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van Wonderen JH, Hall CR, Jiang X, Adamczyk K, Carof A, Heisler I, Piper SEH, Clarke TA, Watmough NJ, Sazanovich IV, Towrie M, Meech SR, Blumberger J, Butt JN. Ultrafast Light-Driven Electron Transfer in a Ru(II)tris(bipyridine)-Labeled Multiheme Cytochrome. J Am Chem Soc 2019; 141:15190-15200. [DOI: 10.1021/jacs.9b06858] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Jessica H. van Wonderen
- School of Chemistry and School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Christopher R. Hall
- School of Chemistry and School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Xiuyun Jiang
- Department of Physics and Astronomy and Thomas-Young Centre, University College London, London WC1E 6BT, United Kingdom
| | - Katrin Adamczyk
- School of Chemistry and School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Antoine Carof
- Department of Physics and Astronomy and Thomas-Young Centre, University College London, London WC1E 6BT, United Kingdom
| | - Ismael Heisler
- School of Chemistry and School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Samuel E. H. Piper
- School of Chemistry and School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Thomas A. Clarke
- School of Chemistry and School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Nicholas J. Watmough
- School of Chemistry and School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Igor V. Sazanovich
- Central Laser Facility, Research Complex at Harwell, Harwell Campus, Didcot, Oxon OX11 0QX, United Kingdom
| | - Michael Towrie
- Central Laser Facility, Research Complex at Harwell, Harwell Campus, Didcot, Oxon OX11 0QX, United Kingdom
| | - Stephen R. Meech
- School of Chemistry and School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Jochen Blumberger
- Department of Physics and Astronomy and Thomas-Young Centre, University College London, London WC1E 6BT, United Kingdom
- Institute for Advanced Study, Technische Universität München, Lichtenbergstrasse 2 a, D-85748 Garching, Germany
| | - Julea N. Butt
- School of Chemistry and School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
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12
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van Wonderen JH, Li D, Piper SEH, Lau CY, Jenner LP, Hall CR, Clarke TA, Watmough NJ, Butt JN. Photosensitised Multiheme Cytochromes as Light-Driven Molecular Wires and Resistors. Chembiochem 2018; 19:2206-2215. [DOI: 10.1002/cbic.201800313] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Indexed: 01/12/2023]
Affiliation(s)
- Jessica H. van Wonderen
- School of Chemistry and School of Biology; University of East Anglia; Norwich Research Park Norfolk NR4 7TJ UK
| | - Daobo Li
- School of Chemistry and School of Biology; University of East Anglia; Norwich Research Park Norfolk NR4 7TJ UK
- Present address: Department of Chemistry; University of Science and Technology of China; Hefei 230026 China
- Present address: Collaborative Innovation Center of Suzhou Nano Science and Technology; Suzhou 215123 China
| | - Samuel E. H. Piper
- School of Chemistry and School of Biology; University of East Anglia; Norwich Research Park Norfolk NR4 7TJ UK
| | - Cheuk Y. Lau
- School of Chemistry and School of Biology; University of East Anglia; Norwich Research Park Norfolk NR4 7TJ UK
| | - Leon P. Jenner
- School of Chemistry and School of Biology; University of East Anglia; Norwich Research Park Norfolk NR4 7TJ UK
| | - Christopher R. Hall
- School of Chemistry and School of Biology; University of East Anglia; Norwich Research Park Norfolk NR4 7TJ UK
- Present address: ARC Centre of Excellence in Exciton Science; School of Chemistry; The University of Melbourne; Parkville Victoria 3010 Australia
| | - Thomas A. Clarke
- School of Chemistry and School of Biology; University of East Anglia; Norwich Research Park Norfolk NR4 7TJ UK
| | - Nicholas J. Watmough
- School of Chemistry and School of Biology; University of East Anglia; Norwich Research Park Norfolk NR4 7TJ UK
| | - Julea N. Butt
- School of Chemistry and School of Biology; University of East Anglia; Norwich Research Park Norfolk NR4 7TJ UK
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13
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Jiang X, Futera Z, Ali ME, Gajdos F, von Rudorff GF, Carof A, Breuer M, Blumberger J. Cysteine Linkages Accelerate Electron Flow through Tetra-Heme Protein STC. J Am Chem Soc 2017; 139:17237-17240. [DOI: 10.1021/jacs.7b08831] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Xiuyun Jiang
- Department
of Physics and Astronomy, University College London, London WC1E 6BT, U.K
| | - Zdenek Futera
- Department
of Physics and Astronomy, University College London, London WC1E 6BT, U.K
| | - Md. Ehesan Ali
- Department
of Physics and Astronomy, University College London, London WC1E 6BT, U.K
| | - Fruzsina Gajdos
- Department
of Physics and Astronomy, University College London, London WC1E 6BT, U.K
| | - Guido F. von Rudorff
- Department
of Physics and Astronomy, University College London, London WC1E 6BT, U.K
| | - Antoine Carof
- Department
of Physics and Astronomy, University College London, London WC1E 6BT, U.K
| | - Marian Breuer
- Department
of Physics and Astronomy, University College London, London WC1E 6BT, U.K
| | - Jochen Blumberger
- Department
of Physics and Astronomy, University College London, London WC1E 6BT, U.K
- Institute
for Advanced Study, Technische Universität München, Lichtenbergstrasse
2a, D-85748 Garching, Germany
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14
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Metabolic Efficiency of Geobacter sulfurreducens Growing on Anodes with Different Redox Potentials. Curr Microbiol 2014; 68:763-8. [DOI: 10.1007/s00284-014-0539-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 12/24/2013] [Indexed: 11/30/2022]
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15
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Takayama Y, Taketa-Sato M, Komori H, Morita K, Kang SJ, Higuchi Y, Akutsu H. Role of π-Electron Systems in Stabilization of the Oxidized Tetraheme Architecture in Cytochromec3. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2011. [DOI: 10.1246/bcsj.20110039] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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16
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Qian Y, Paquete CM, Louro RO, Ross DE, Labelle E, Bond DR, Tien M. Mapping the iron binding site(s) on the small tetraheme cytochrome of Shewanella oneidensis MR-1. Biochemistry 2011; 50:6217-24. [PMID: 21682327 DOI: 10.1021/bi2005015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In the model microbe Shewanella oneidensis, multi-heme proteins are utilized for respiratory metabolism where metals serve as the terminal electron acceptor. Among those is the periplasm-localized small tetraheme cytochrome (STC). STC has been extensively characterized structurally and electrochemically to which electron flow in and out of the protein has been modeled. However, until the present work, no kinetic studies have been performed to probe the route of electron flow or to determine the iron-binding site on STC. Using iron chelated by EDTA, NTA, or citrate, we have used chemical modification, site-directed mutagenesis along with isothermal titration calorimetry (ITC), and stopped-flow measurements to identify the iron binding site of STC. Chemical modifications of STC revealed that carboxyl groups on STC are involved in binding of EDTA-Fe(3+). Scanning mutagenesis was performed on Asp and Glu to probe the putative iron-binding site on STC. Two STC mutants (D21N; D80N) showed ∼70% decrease in observed electron transfer rate constant with EDTA-Fe(3+) from transient-state kinetic measurements. The impaired reactivity of STC (D80N/D21N) with EDTA-Fe(3+) was further confirmed by a significant decrease (>10-fold) in iron binding affinity.
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Affiliation(s)
- Yufeng Qian
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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17
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Firer-Sherwood MA, Bewley KD, Mock JY, Elliott SJ. Tools for resolving complexity in the electron transfer networks of multiheme cytochromes c. Metallomics 2011; 3:344-8. [PMID: 21327265 DOI: 10.1039/c0mt00097c] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Examining electron transfer between two proteins with identical spectroscopic signatures is a challenging task. It is supposed that several multiheme cytochromes in Shewanella oneidensis form a molecular "wire" through which electrons are transported across the cellular space and a direct study of this transient protein-protein interaction has not yet been reported. In this study, we present variations on catalytic protein film voltammetry and an anaerobic affinity chromatography assay to demonstrate unidirectional electron transfer between proposed protein pairs. Through use of these techniques, we are able to confirm the transient interactions between these cytochromes, supporting the model of electron transfer that is present in the literature.
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18
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One simple step in the identification of the cofactors signals, one giant leap for the solution structure determination of multiheme proteins. Biochem Biophys Res Commun 2010; 393:466-70. [PMID: 20152799 DOI: 10.1016/j.bbrc.2010.02.024] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Accepted: 02/05/2010] [Indexed: 11/24/2022]
Abstract
Multiheme proteins play major roles in various biological systems. Structural information on these systems in solution is crucial to understand their functional mechanisms. However, the presence of numerous proton-containing groups in the heme cofactors and the magnetic properties of the heme iron, in particular in the oxidised state, complicates significantly the assignment of the NMR signals. Consequently, the multiheme proteins superfamily is extremely under-represented in structural databases, which constitutes a severe bottleneck in the elucidation of their structural-functional relationships. In this work, we present a strategy that simplifies the assignment of the NMR signals in multiheme proteins and, concomitantly, their solution structure determination, using the triheme cytochrome PpcA from the bacterium Geobacter sulfurreducens as a model. Cost-effective isotopic labeling was used to double label (13C/15N) the protein in its polypeptide chain, with the correct folding and heme post-translational modifications. The combined analysis of 1H-13C HSQC NMR spectra obtained for labeled and unlabeled samples of PpcA allowed a straight discrimination between the heme cofactors and the polypeptide chain signals and their confident assignment. The results presented here will be the foundations to assist solution structure determination of multiheme proteins, which are still very scarce in the literature.
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19
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Paquete CM, Saraiva IH, Calçada E, Louro RO. Molecular basis for directional electron transfer. J Biol Chem 2010; 285:10370-5. [PMID: 20089857 DOI: 10.1074/jbc.m109.078337] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Biological macromolecules involved in electron transfer reactions display chains of closely packed redox cofactors when long distances must be bridged. This is a consequence of the need to maintain a rate of transfer compatible with metabolic activity in the framework of the exponential decay of electron tunneling with distance. In this work intermolecular electron transfer was studied in kinetic experiments performed with the small tetraheme cytochrome from Shewanella oneidensis MR-1 and from Shewanella frigidimarina NCIMB400 using non-physiological redox partners. This choice allowed the effect of specific recognition and docking to be eliminated from the measured rates. The results were analyzed with a kinetic model that uses the extensive thermodynamic characterization of these proteins reported in the literature to discriminate the kinetic contribution of each heme to the overall rate of electron transfer. This analysis shows that, in this redox chain that spans 23 A, the kinetic properties of the individual hemes establish a functional specificity for each redox center. This functional specificity combined with the thermodynamic properties of these soluble proteins ensures directional electron flow within the cytochrome even outside of the context of a functioning respiratory chain.
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Affiliation(s)
- Catarina M Paquete
- Instituto de Tecnologia Química e Biológica, Av. da República (EAN), 2780-157 Oeiras, Portugal
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20
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Paquete CM, Louro RO. Molecular details of multielectron transfer: the case of multiheme cytochromes from metal respiring organisms. Dalton Trans 2009; 39:4259-66. [PMID: 20422082 DOI: 10.1039/b917952f] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Shewanella are facultative anaerobic bacteria of remarkable respiratory versatility that includes the dissimilatory reduction of metal ores. They contain a large number of multiheme c-type cytochromes that play a significant role in various anaerobic respiratory processes. Of all the cytochromes found in Shewanella, only the two most abundant periplasmic cytochromes, the small tetraheme cytochrome (STC) and flavocytochrome c(3) (Fcc(3)) have been structurally characterized. For these two proteins the molecular bases for their redox properties were determined using spectroscopic methods based on paramagnetic NMR, that allow the contribution of specific hemes to be discriminated. In this perspective these results are reviewed in the context of the continuing effort to understand the molecular mechanisms of electron transfer in the respiratory chains of these organisms.
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21
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Zheng Z, Gunner MR. Analysis of the electrochemistry of hemes with E(m)s spanning 800 mV. Proteins 2009; 75:719-34. [PMID: 19003997 DOI: 10.1002/prot.22282] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The free energy of heme reduction in different proteins is found to vary over more than 18 kcal/mol. It is a challenge to determine how proteins manage to achieve this enormous range of E(m)s with a single type of redox cofactor. Proteins containing 141 unique hemes of a-, b-, and c-type, with bis-His, His-Met, and aquo-His ligation were calculated using Multi-Conformation Continuum Electrostatics (MCCE). The experimental E(m)s range over 800 mV from -350 mV in cytochrome c(3) to 450 mV in cytochrome c peroxidase (vs. SHE). The quantitative analysis of the factors that modulate heme electrochemistry includes the interactions of the heme with its ligands, the solvent, the protein backbone, and sidechains. MCCE calculated E(m)s are in good agreement with measured values. Using no free parameters the slope of the line comparing calculated and experimental E(m)s is 0.73 (R(2) = 0.90), showing the method accounts for 73% of the observed E(m) range. Adding a +160 mV correction to the His-Met c-type hemes yields a slope of 0.97 (R(2) = 0.93). With the correction 65% of the hemes have an absolute error smaller than 60 mV and 92% are within 120 mV. The overview of heme proteins with known structures and E(m)s shows both the lowest and highest potential hemes are c-type, whereas the b-type hemes are found in the middle E(m) range. In solution, bis-His ligation lowers the E(m) by approximately 205 mV relative to hemes with His-Met ligands. The bis-His, aquo-His, and His-Met ligated b-type hemes all cluster about E(m)s which are approximately 200 mV more positive in protein than in water. In contrast, the low potential bis-His c-type hemes are shifted little from in solution, whereas the high potential His-Met c-type hemes are raised by approximately 300 mV from solution. The analysis shows that no single type of interaction can be identified as the most important in setting heme electrochemistry in proteins. For example, the loss of solvation (reaction field) energy, which raises the E(m), has been suggested to be a major factor in tuning in situ E(m)s. However, the calculated solvation energy vs. experimental E(m) shows a slope of 0.2 and R(2) of 0.5 thus correlates weakly with E(m)s. All other individual interactions show even less correlation with E(m). However the sum of these terms does reproduce the range of observed E(m)s. Therefore, different proteins use different aspects of their structures to modulate the in situ heme electrochemistry. This study also shows that the calculated E(m)s are relatively insensitive to different heme partial charges and to the protein dielectric constant used in the simulation.
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Affiliation(s)
- Zhong Zheng
- Department of Physics, The City College of New York, New York, NY, USA
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22
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Pessanha M, Rothery EL, Miles CS, Reid GA, Chapman SK, Louro RO, Turner DL, Salgueiro CA, Xavier AV. Tuning of functional heme reduction potentials in Shewanella fumarate reductases. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2009; 1787:113-20. [DOI: 10.1016/j.bbabio.2008.11.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Revised: 11/06/2008] [Accepted: 11/07/2008] [Indexed: 11/15/2022]
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23
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The tetraheme cytochrome from Shewanella oneidensis MR-1 shows thermodynamic bias for functional specificity of the hemes. J Biol Inorg Chem 2008; 14:375-85. [DOI: 10.1007/s00775-008-0455-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2008] [Accepted: 11/14/2008] [Indexed: 10/21/2022]
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24
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Paixão VB, Salgueiro CA, Brennan L, Reid GA, Chapman SK, Turner DL. The Solution Structure of a Tetraheme Cytochrome from Shewanella frigidimarina Reveals a Novel Family Structural Motif. Biochemistry 2008; 47:11973-80. [DOI: 10.1021/bi801326j] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Vitor B. Paixão
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Rua da Quinta Grande 6, 2780-156 Oeiras, Portugal, Requimte, CQFB, Requimte, CQFB, Departamento de Química da Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, Quinta da Torre, 2829-516 Caparica, Portugal, UCD Conway Institute, UCD School of Agriculture, Food Science and Veterinary Medicine, UCD, Belfield, Dublin 4, Ireland, Institute of Structural and Molecular Biology, University of Edinburgh, Mayfield Road,
| | - Carlos A. Salgueiro
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Rua da Quinta Grande 6, 2780-156 Oeiras, Portugal, Requimte, CQFB, Requimte, CQFB, Departamento de Química da Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, Quinta da Torre, 2829-516 Caparica, Portugal, UCD Conway Institute, UCD School of Agriculture, Food Science and Veterinary Medicine, UCD, Belfield, Dublin 4, Ireland, Institute of Structural and Molecular Biology, University of Edinburgh, Mayfield Road,
| | - Lorraine Brennan
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Rua da Quinta Grande 6, 2780-156 Oeiras, Portugal, Requimte, CQFB, Requimte, CQFB, Departamento de Química da Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, Quinta da Torre, 2829-516 Caparica, Portugal, UCD Conway Institute, UCD School of Agriculture, Food Science and Veterinary Medicine, UCD, Belfield, Dublin 4, Ireland, Institute of Structural and Molecular Biology, University of Edinburgh, Mayfield Road,
| | - Graeme A. Reid
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Rua da Quinta Grande 6, 2780-156 Oeiras, Portugal, Requimte, CQFB, Requimte, CQFB, Departamento de Química da Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, Quinta da Torre, 2829-516 Caparica, Portugal, UCD Conway Institute, UCD School of Agriculture, Food Science and Veterinary Medicine, UCD, Belfield, Dublin 4, Ireland, Institute of Structural and Molecular Biology, University of Edinburgh, Mayfield Road,
| | - Stephen K. Chapman
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Rua da Quinta Grande 6, 2780-156 Oeiras, Portugal, Requimte, CQFB, Requimte, CQFB, Departamento de Química da Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, Quinta da Torre, 2829-516 Caparica, Portugal, UCD Conway Institute, UCD School of Agriculture, Food Science and Veterinary Medicine, UCD, Belfield, Dublin 4, Ireland, Institute of Structural and Molecular Biology, University of Edinburgh, Mayfield Road,
| | - David L. Turner
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Rua da Quinta Grande 6, 2780-156 Oeiras, Portugal, Requimte, CQFB, Requimte, CQFB, Departamento de Química da Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, Quinta da Torre, 2829-516 Caparica, Portugal, UCD Conway Institute, UCD School of Agriculture, Food Science and Veterinary Medicine, UCD, Belfield, Dublin 4, Ireland, Institute of Structural and Molecular Biology, University of Edinburgh, Mayfield Road,
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25
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Takayama Y, Werbeck ND, Komori H, Morita K, Ozawa K, Higuchi Y, Akutsu H. Strategic roles of axial histidines in structure formation and redox regulation of tetraheme cytochrome c3. Biochemistry 2008; 47:9405-15. [PMID: 18702516 DOI: 10.1021/bi8005708] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Tetraheme cytochrome c 3 (cyt c 3) exhibits extremely low reduction potentials and unique properties. Since axial ligands should be the most important factors for this protein, every axial histidine of Desulfovibrio vulgaris Miyazaki F cyt c 3 was replaced with methionine, one by one. On mutation at the fifth ligand, the relevant heme could not be linked to the polypeptide, revealing the essential role of the fifth histidine in heme linking. The fifth histidine is the key residue in the structure formation and redox regulation of a c-type cytochrome. A crystal structure has been obtained for only H25M cyt c 3. The overall structure was not affected by the mutation except for the sixth methionine coordination at heme 3. NMR spectra revealed that each mutated methionine is coordinated to the sixth site of the relevant heme in the reduced state, while ligand conversion takes place at hemes 1 and 4 during oxidation at pH 7. The replacement of the sixth ligand with methionine caused an increase in the reduction potential of the mutated heme of 222-244 mV. The midpoint potential of a triheme H52M cyt c 3 is higher than that of the wild type by approximately 50 mV, suggesting a contribution of the tetraheme architecture to the lowering of the reduction potentials. The hydrogen bonding of Thr24 with an axial ligand induces a decrease in reduction potential of approximately 50 mV. In conclusion, the bis-histidine coordination is strategically essential for the structure formation and the extremely low reduction potential of cyt c 3.
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Affiliation(s)
- Yuki Takayama
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
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26
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Electrochemical interrogations of the Mtr cytochromes from Shewanella: opening a potential window. J Biol Inorg Chem 2008; 13:849-54. [DOI: 10.1007/s00775-008-0398-z] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2008] [Accepted: 06/12/2008] [Indexed: 10/21/2022]
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27
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Morgado L, Bruix M, Orshonsky V, Londer YY, Duke NEC, Yang X, Pokkuluri PR, Schiffer M, Salgueiro CA. Structural insights into the modulation of the redox properties of two Geobacter sulfurreducens homologous triheme cytochromes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2008; 1777:1157-65. [PMID: 18534185 DOI: 10.1016/j.bbabio.2008.04.043] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2008] [Revised: 04/07/2008] [Accepted: 04/28/2008] [Indexed: 11/17/2022]
Abstract
The redox properties of a periplasmic triheme cytochrome, PpcB from Geobacter sulfurreducens, were studied by NMR and visible spectroscopy. The structure of PpcB was determined by X-ray diffraction. PpcB is homologous to PpcA (77% sequence identity), which mediates cytoplasmic electron transfer to extracellular acceptors and is crucial in the bioenergetic metabolism of Geobacter spp. The heme core structure of PpcB in solution, probed by 2D-NMR, was compared to that of PpcA. The results showed that the heme core structures of PpcB and PpcA in solution are similar, in contrast to their crystal structures where the heme cores of the two proteins differ from each other. NMR redox titrations were carried out for both proteins and the order of oxidation of the heme groups was determined. The microscopic properties of PpcB and PpcA redox centers showed important differences: (i) the order in which hemes become oxidized is III-I-IV for PpcB, as opposed to I-IV-III for PpcA; (ii) the redox-Bohr effect is also different in the two proteins. The different redox features observed between PpcB and PpcA suggest that each protein uniquely modulates the properties of their co-factors to assure effectiveness in their respective metabolic pathways. The origins of the observed differences are discussed.
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Affiliation(s)
- Leonor Morgado
- Requimte-CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus Caparica, 2829-516 Caparica, Portugal
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28
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Morgado L, Bruix M, Londer YY, Pokkuluri PR, Schiffer M, Salgueiro CA. Redox-linked conformational changes of a multiheme cytochrome from Geobacter sulfurreducens. Biochem Biophys Res Commun 2007; 360:194-8. [PMID: 17583674 DOI: 10.1016/j.bbrc.2007.06.026] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2007] [Accepted: 06/05/2007] [Indexed: 11/29/2022]
Abstract
Multiheme c-type cytochromes from members of the Desulfovibrionacea and Geobactereacea families play crucial roles in the bioenergetics of these microorganisms. Thermodynamic studies using NMR and visible spectroscopic techniques on tetraheme cytochromes c(3) isolated from Desulfovibrio spp. and more recently on a triheme cytochrome from Geobacter sulfurreducens showed that the properties of each redox centre are modulated by the neighbouring redox centres enabling these proteins to perform energy transduction and thus contributing to cellular energy conservation. Electron/proton transfer coupling relies on redox-linked conformational changes that were addressed for some multiheme cytochromes from the comparison of protein structure of fully reduced and fully oxidised forms. In this work, we identify for the first time in a multiheme cytochrome the simultaneous presence of two different conformations in solution. This was achieved by probing the different oxidation stages of a triheme cytochrome isolated from G. sulfurreducens using 2D-NMR techniques. The results presented here will be the foundations to evaluate the modulation of the redox centres properties by conformational changes that occur during the reoxidation of a multiheme protein.
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Affiliation(s)
- Leonor Morgado
- Requimte - CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
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29
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Akutsu H, Takayama Y. Functional roles of the heme architecture and its environment in tetraheme cytochrome c. Acc Chem Res 2007; 40:171-8. [PMID: 17370988 DOI: 10.1021/ar030262g] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cytochromes are involved in a wide variety of redox reactions in living systems. Some of them contain multiple hemes such as Desulfovibrio cytochrome c3 and Shewanella small tetraheme cytochrome c. The significance of c-type tetraheme architectures was discussed. A cyclic heme architecture and its environment regulate the extremely low redox potentials of cytochrome c3 in addition to bis-imidazole coordination and heme exposure. Each heme in cytochrome c3 plays a different role in the electron transport to/from [NiFe] hydrogenase and the specific CO-binding. In contrast, the chain-like heme architecture in Shewanella small tetraheme cytochrome c and soluble fumarate reductase provides a pathway for directional electron transfer. Thus, the tetraheme architectures do not comprise simple heme assemblies but sophisticated devices.
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Affiliation(s)
- Hideo Akutsu
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita 565-0871, Japan.
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30
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Biju V, Pan D, Gorby YA, Fredrickson J, McLean J, Saffarini D, Lu HP. Combined spectroscopic and topographic characterization of nanoscale domains and their distributions of a redox protein on bacterial cell surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:1333-8. [PMID: 17241055 DOI: 10.1021/la061343z] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Redox protein nanoscale domains on the cell surface of a bacterium, Shewanella oneidensis MR1, grown in the absence and presence of electron acceptors, is topographically characterized using combined atomic force microscopy (AFM) and confocal surface enhanced Raman scattering (SERS) spectroscopy. The protruding nanoscale domains on the outer membrane of S. oneidensis were observed, as was their disappearance upon exposure to electron acceptors such as oxygen, nitrate, fumarate, and iron nitrilotriacetate (FeNTA). Using SERS spectroscopy, a redox heme protein was identified as a major component of the cell surface domains. This conclusion was further confirmed by the disappearance of Raman vibrational frequencies, characteristic of heme proteins, upon exposure of the cells to electron acceptors. Our experimental results from our AFM imaging and SERS spectroscopy, consistent with the literature, suggest the protruding nanoscale surface domains as heme-containing secretions. Our results on the distributions of redox proteins on microbial cell surfaces will be helpful for a mechanistic understanding of the behaviors of surface proteins and their interactions with redox environments.
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Affiliation(s)
- Vasudevanpillai Biju
- Fundamental Science Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA
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31
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Londer YY, Pokkuluri PR, Orshonsky V, Orshonsky L, Schiffer M. Heterologous expression of dodecaheme “nanowire” cytochromes c from Geobacter sulfurreducens. Protein Expr Purif 2006; 47:241-8. [PMID: 16403647 DOI: 10.1016/j.pep.2005.11.017] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2005] [Revised: 11/11/2005] [Accepted: 11/18/2005] [Indexed: 11/30/2022]
Abstract
Multiheme cytochromes c are difficult to produce in heterologous systems. The genome of delta-proteobacterium Geobacter sulfurreducens contains more than a hundred genes coding for c-type cytochromes. Among those are two dodecaheme cytochromes c representing a new class of multiheme cytochromes, whose putative structure is a one-dimensional array of small highly homologous domains that contain three hemes and are covalently bound by short linkers. They are likely to form "nanowires" that are part of the electron transfer chain. We cloned the genes coding for the two cytochromes into a vector we developed for ligation-independent cloning of proteins targeted to the Escherichia coli periplasmic space. We expressed the proteins in E. coli co-transformed with a plasmid harboring the cytochrome c maturation genes. Expression levels were optimized by varying IPTG concentrations used for induction. Although both proteins appeared insoluble or strongly associated with cell membranes, they were solubilized using 0.5 M sodium chloride which was more selective than conventional solubilizing agents, such as HEGA-10 or beta-octylglucoside. The solubilized proteins were dialyzed and purified by cation exchange chromatography followed by gel filtration. Mass-spectrometry analysis confirmed that both purified proteins contained the complete set of covalently attached hemes, 12 per molecule. Their visible spectra were typical of c-type cytochromes. Both proteins were successfully crystallized.
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Affiliation(s)
- Yuri Y Londer
- Biosciences Division, Argonne National Laboratory, Argonne, IL 60439, USA.
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32
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Londer YY, Pokkuluri PR, Erickson J, Orshonsky V, Schiffer M. Heterologous expression of hexaheme fragments of a multidomain cytochrome from Geobacter sulfurreducens representing a novel class of cytochromes c. Protein Expr Purif 2005; 39:254-60. [PMID: 15642477 DOI: 10.1016/j.pep.2004.10.015] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2004] [Revised: 10/14/2004] [Indexed: 11/26/2022]
Abstract
Multiheme cytochromes c are of great interest for researchers for a variety of reasons but difficult to obtain in quantities sufficient for the majority of studies. The genome of delta-proteobacterium Geobacter sulfurreducens contains more than a hundred genes coding for c-type cytochromes. Three of them represent a new class of multiheme cytochromes characterized by a mixed type of heme coordination and multidomain organization. We cloned and expressed in Escherichia coli three hexaheme fragments corresponding to two-domain fragments of one such protein containing 12 heme binding motifs and believed to consist of four triheme domains. Despite high sequence similarity among the fragments, expression levels varied significantly. Expression was optimized either by host strain variation or by reducing the rate of apoprotein synthesis. All three fragments were purified by cation exchange followed by gel filtration and were shown to contain six covalently attached hemes as confirmed by mass spectrometry. Their visible spectra are typical of c-type cytochromes. One of the fragments was crystallized and its preliminary X-ray structure shows two separate domains.
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Affiliation(s)
- Yuri Y Londer
- Biosciences Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439, USA.
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Pessanha M, Rothery EL, Louro RO, Turner DL, Miles CS, Reid GA, Chapman SK, Xavier AV, Salgueiro CA. Redox behaviour of the haem domain of flavocytochromec3fromShewanella frigidimarinaprobed by NMR. FEBS Lett 2004; 578:185-90. [PMID: 15581639 DOI: 10.1016/j.febslet.2004.10.098] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2004] [Accepted: 10/31/2004] [Indexed: 11/19/2022]
Abstract
Flavocytochrome c3 from Shewanella frigidimarina (fcc3) is a tetrahaem periplasmic protein of 64 kDa with fumarate reductase activity. This work reports the first example of NMR techniques applied to the assignment of the thermodynamic order of oxidation of the four individual haems for such large protein, expanding its applicability to a wide range of proteins. NMR data from partially and fully oxidised samples of fcc3 and a mutated protein with an axial ligand of haem IV replaced by alanine were compared with calculated chemical shifts, allowing the structural assignment of the signals and the unequivocal determination of the order of oxidation of the haems. As oxidation progresses the fcc3 haem domain is polarised, with haems I and II much more oxidised than haems III and IV, haem IV being the most reduced. Thus, during catalysis as an electron is taken by the flavin adenosine dinucleotide from haem IV, haem III is eager to re-reduce haem IV, allowing the transfer of two electrons to the active site.
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Affiliation(s)
- Miguel Pessanha
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Rua da Quinta Grande 6, 2780-156 Oeiras, Portugal
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Takayama Y, Harada E, Kobayashi R, Ozawa K, Akutsu H. Roles of Noncoordinated Aromatic Residues in Redox Regulation of Cytochrome c3 from Desulfovibrio vulgaris Miyazaki F. Biochemistry 2004; 43:10859-66. [PMID: 15323546 DOI: 10.1021/bi049551i] [Citation(s) in RCA: 18] [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
The roles of aromatic residues in redox regulation of cytochrome c(3) were investigated by site-directed mutagenesis at every aromatic residue except for axial ligands (Phe20, Tyr43, Tyr65, Tyr66, His67, and Phe76). The mutations at Phe20 induced large chemical shift changes in the NMR signals for hemes 1 and 3, and large changes in the microscopic redox potentials of hemes 1 and 3. The NMR signals of the axial ligands of hemes 1 and 3 were also affected. Analysis of the nature of the mutations revealed that a hydrophobic environment and aromaticity are important for the reduction of the redox potentials of hemes 1 and 3, respectively. There was also a global effect. The replacement of Tyr66 with leucine induced chemical shift changes for heme 4, and changes in the microscopic redox potentials of heme 4. The mutations of Tyr65 induced changes in the chemical shifts and microscopic redox potentials for every heme, suggesting that Tyr65 stabilizes the global conformation, thereby reducing the redox potentials. In contrast, although the mutations of His67 and Phe76 caused chemical shift changes for heme 2, they did not affect its redox potentials, showing these residues are not important. All noncoordinated aromatic residues conserved in the cytochrome c(3) subfamily with heme binding motifs CXXCH, CXXXXCH, CXXCH, and CXXXXCH (Phe20, Tyr43, and Tyr66) are involved in the pi-pi interaction, which causes a decrease in the redox potential of the interacting heme. The global effect can be attributed to either direct or indirect interactions among the four hemes in the cyclic architecture.
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Affiliation(s)
- Yuki Takayama
- Institute for Protein Research, Osaka University, Yamadaoka, Suita 565-0871, Japan
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