1
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Deng Y, Carnevale V, Ditchfield R, Pletneva EV. Applications of the Newly Developed Force-Field Parameters Uncover a Dynamic Nature of Ω-Loop C in the Lys-Ligated Alkaline Form of Cytochrome c. J Phys Chem B 2024; 128:5935-5949. [PMID: 38864552 DOI: 10.1021/acs.jpcb.4c00625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2024]
Abstract
Lys-ligated cytochromes make up an emerging family of heme proteins. Density functional theory calculations on the amine/imidazole-ligated c-type ferric heme were employed to develop force-field parameters for molecular dynamics (MD) simulations of structural and dynamic features of these proteins. The new force-field parameters were applied to the alkaline form of yeast iso-1 cytochrome c to rationalize discrepancies resulting from distinct experimental conditions in prior structural studies and to provide insights into the mechanisms of the alkaline transition. Our simulations have revealed the dynamic nature of Ω-loop C in the Lys-ligated protein and its unfolding in the Lys-ligated conformer having this loop in the same position as in the native Met-ligated protein. The proximity of Tyr67 or Tyr74 to the Lys ligand of ferric heme iron suggests a possible mechanism of the backward alkaline transition where a proton donor Tyr assists in Lys dissociation. The developed force-field parameters will be useful in structural and dynamic characterization of other native or engineered Lys-ligated heme proteins.
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Affiliation(s)
- Yunling Deng
- Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755, United States
| | - Vincenzo Carnevale
- Institute for Genomics and Evolutionary Medicine, Institute for Computational Molecular Science, and Department of Biology, Temple University, Philadelphia, Pennsylvania 19122, United States
| | - Robert Ditchfield
- Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755, United States
| | - Ekaterina V Pletneva
- Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755, United States
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2
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Kubiak X, Polsinelli I, Chavas LMG, Fyfe CD, Guillot A, Fradale L, Brewee C, Grimaldi S, Gerbaud G, Thureau A, Legrand P, Berteau O, Benjdia A. Structural and mechanistic basis for RiPP epimerization by a radical SAM enzyme. Nat Chem Biol 2024; 20:382-391. [PMID: 38158457 DOI: 10.1038/s41589-023-01493-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 10/30/2023] [Indexed: 01/03/2024]
Abstract
D-Amino acid residues, found in countless peptides and natural products including ribosomally synthesized and post-translationally modified peptides (RiPPs), are critical for the bioactivity of several antibiotics and toxins. Recently, radical S-adenosyl-L-methionine (SAM) enzymes have emerged as the only biocatalysts capable of installing direct and irreversible epimerization in RiPPs. However, the mechanism underpinning this biochemical process is ill-understood and the structural basis for this post-translational modification remains unknown. Here we report an atomic-resolution crystal structure of a RiPP-modifying radical SAM enzyme in complex with its substrate properly positioned in the active site. Crystallographic snapshots, size-exclusion chromatography-small-angle x-ray scattering, electron paramagnetic resonance spectroscopy and biochemical analyses reveal how epimerizations are installed in RiPPs and support an unprecedented enzyme mechanism for peptide epimerization. Collectively, our study brings unique perspectives on how radical SAM enzymes interact with RiPPs and catalyze post-translational modifications in natural products.
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Affiliation(s)
- Xavier Kubiak
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, ChemSyBio, Jouy-en-Josas, France
| | - Ivan Polsinelli
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, ChemSyBio, Jouy-en-Josas, France
| | | | - Cameron D Fyfe
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, ChemSyBio, Jouy-en-Josas, France
| | - Alain Guillot
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, ChemSyBio, Jouy-en-Josas, France
| | - Laura Fradale
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, ChemSyBio, Jouy-en-Josas, France
| | - Clémence Brewee
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, ChemSyBio, Jouy-en-Josas, France
| | | | | | - Aurélien Thureau
- Synchrotron SOLEIL, HelioBio Group, L'Orme des Merisiers, Saint-Aubin, France
| | - Pierre Legrand
- Synchrotron SOLEIL, HelioBio Group, L'Orme des Merisiers, Saint-Aubin, France
| | - Olivier Berteau
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, ChemSyBio, Jouy-en-Josas, France.
| | - Alhosna Benjdia
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, ChemSyBio, Jouy-en-Josas, France.
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3
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Petushkova E, Khasimov M, Mayorova E, Delegan Y, Frantsuzova E, Bogun A, Galkina E, Tsygankov A. The Complete Genome of a Novel Typical Species Thiocapsa bogorovii and Analysis of Its Central Metabolic Pathways. Microorganisms 2024; 12:391. [PMID: 38399794 PMCID: PMC10892978 DOI: 10.3390/microorganisms12020391] [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: 01/15/2024] [Revised: 02/08/2024] [Accepted: 02/10/2024] [Indexed: 02/25/2024] Open
Abstract
The purple sulfur bacterium Thiocapsa roseopersicina BBS is interesting from both fundamental and practical points of view. It possesses a thermostable HydSL hydrogenase, which is involved in the reaction of reversible hydrogen activation and a unique reaction of sulfur reduction to hydrogen sulfide. It is a very promising enzyme for enzymatic hydrogenase electrodes. There are speculations that HydSL hydrogenase of purple bacteria is closely related to sulfur metabolism, but confirmation is required. For that, the full genome sequence is necessary. Here, we sequenced and assembled the complete genome of this bacterium. The analysis of the obtained whole genome, through an integrative approach that comprised estimating the Average Nucleotide Identity (ANI) and digital DNA-DNA hybridization (DDH) parameters, allowed for validation of the systematic position of T. roseopersicina as T. bogorovii BBS. For the first time, we have assembled the whole genome of this typical strain of a new bacterial species and carried out its functional description against another purple sulfur bacterium: Allochromatium vinosum DSM 180T. We refined the automatic annotation of the whole genome of the bacteria T. bogorovii BBS and localized the genomic positions of several studied genes, including those involved in sulfur metabolism and genes encoding the enzymes required for the TCA and glyoxylate cycles and other central metabolic pathways. Eleven additional genes coding proteins involved in pigment biosynthesis was found.
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Affiliation(s)
- Ekaterina Petushkova
- Institute of Basic Biological Problems, Federal Research Center “Pushchino Scientific Center for Biological Research of Russian Academy of Sciences” (FRC PSCBR RAS), 142290 Pushchino, Moscow Region, Russia; (M.K.); (E.M.); (A.T.)
| | - Makhmadyusuf Khasimov
- Institute of Basic Biological Problems, Federal Research Center “Pushchino Scientific Center for Biological Research of Russian Academy of Sciences” (FRC PSCBR RAS), 142290 Pushchino, Moscow Region, Russia; (M.K.); (E.M.); (A.T.)
| | - Ekaterina Mayorova
- Institute of Basic Biological Problems, Federal Research Center “Pushchino Scientific Center for Biological Research of Russian Academy of Sciences” (FRC PSCBR RAS), 142290 Pushchino, Moscow Region, Russia; (M.K.); (E.M.); (A.T.)
| | - Yanina Delegan
- Institute of Biochemistry and Physiology of Microorganisms, Federal Research Center “Pushchino Scientific Center for Biological Research of Russian Academy of Sciences” (FRC PSCBR RAS), 142290 Pushchino, Moscow Region, Russia; (Y.D.); (E.F.); (A.B.)
| | - Ekaterina Frantsuzova
- Institute of Biochemistry and Physiology of Microorganisms, Federal Research Center “Pushchino Scientific Center for Biological Research of Russian Academy of Sciences” (FRC PSCBR RAS), 142290 Pushchino, Moscow Region, Russia; (Y.D.); (E.F.); (A.B.)
| | - Alexander Bogun
- Institute of Biochemistry and Physiology of Microorganisms, Federal Research Center “Pushchino Scientific Center for Biological Research of Russian Academy of Sciences” (FRC PSCBR RAS), 142290 Pushchino, Moscow Region, Russia; (Y.D.); (E.F.); (A.B.)
| | - Elena Galkina
- State Research Center for Applied Microbiology and Biotechnology, 142279 Obolensk, Moscow Region, Russia;
| | - Anatoly Tsygankov
- Institute of Basic Biological Problems, Federal Research Center “Pushchino Scientific Center for Biological Research of Russian Academy of Sciences” (FRC PSCBR RAS), 142290 Pushchino, Moscow Region, Russia; (M.K.); (E.M.); (A.T.)
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4
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Kanao T. Tetrathionate hydrolase from the acidophilic microorganisms. Front Microbiol 2024; 15:1338669. [PMID: 38348185 PMCID: PMC10859504 DOI: 10.3389/fmicb.2024.1338669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 01/15/2024] [Indexed: 02/15/2024] Open
Abstract
Tetrathionate hydrolase (TTH) is a unique enzyme found in acidophilic sulfur-oxidizing microorganisms, such as bacteria and archaea. This enzyme catalyzes the hydrolysis of tetrathionate to thiosulfate, elemental sulfur, and sulfate. It is also involved in dissimilatory sulfur oxidation metabolism, the S4-intermediate pathway. TTHs have been purified and characterized from acidophilic autotrophic sulfur-oxidizing microorganisms. All purified TTHs show an optimum pH in the acidic range, suggesting that they are localized in the periplasmic space or outer membrane. In particular, the gene encoding TTH from Acidithiobacillus ferrooxidans (Af-tth) was identified and recombinantly expressed in Escherichia coli cells. TTH activity could be recovered from the recombinant inclusion bodies by acid refolding treatment for crystallization. The mechanism of tetrathionate hydrolysis was then elucidated by X-ray crystal structure analysis. Af-tth is highly expressed in tetrathionate-grown cells but not in iron-grown cells. These unique structural properties, reaction mechanisms, gene expression, and regulatory mechanisms are discussed in this review.
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Affiliation(s)
- Tadayoshi Kanao
- Department of Agricultural and Biological Chemistry, Graduate School of Environment, Life, Natural Science, and Technology, Okayama University, Okayama, Japan
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5
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Nosalova L, Piknova M, Kolesarova M, Pristas P. Cold Sulfur Springs-Neglected Niche for Autotrophic Sulfur-Oxidizing Bacteria. Microorganisms 2023; 11:1436. [PMID: 37374938 DOI: 10.3390/microorganisms11061436] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 05/15/2023] [Accepted: 05/25/2023] [Indexed: 06/29/2023] Open
Abstract
Since the beginning of unicellular life, dissimilation reactions of autotrophic sulfur bacteria have been a crucial part of the biogeochemical sulfur cycle on Earth. A wide range of sulfur oxidation states is reflected in the diversity of metabolic pathways used by sulfur-oxidizing bacteria. This metabolically and phylogenetically diverse group of microorganisms inhabits a variety of environments, including extreme environments. Although they have been of interest to microbiologists for more than 150 years, meso- and psychrophilic chemolithoautotrophic sulfur-oxidizing microbiota are less studied compared to the microbiota of hot springs. Several recent studies suggested that cold sulfur waters harbor unique, yet not described, bacterial taxa.
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Affiliation(s)
- Lea Nosalova
- Department of Microbiology, Faculty of Science, Institute of Biology and Ecology, Pavol Jozef Safarik University in Kosice, 041 54 Kosice, Slovakia
| | - Maria Piknova
- Department of Microbiology, Faculty of Science, Institute of Biology and Ecology, Pavol Jozef Safarik University in Kosice, 041 54 Kosice, Slovakia
| | - Mariana Kolesarova
- Department of Microbiology, Faculty of Science, Institute of Biology and Ecology, Pavol Jozef Safarik University in Kosice, 041 54 Kosice, Slovakia
| | - Peter Pristas
- Centre of Biosciences, Institute of Animal Physiology, Slovak Academy of Sciences, 040 01 Kosice, Slovakia
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6
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Whaley-Martin KJ, Chen LX, Nelson TC, Gordon J, Kantor R, Twible LE, Marshall S, McGarry S, Rossi L, Bessette B, Baron C, Apte S, Banfield JF, Warren LA. O 2 partitioning of sulfur oxidizing bacteria drives acidity and thiosulfate distributions in mining waters. Nat Commun 2023; 14:2006. [PMID: 37037821 PMCID: PMC10086054 DOI: 10.1038/s41467-023-37426-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 03/14/2023] [Indexed: 04/12/2023] Open
Abstract
The acidification of water in mining areas is a global environmental issue primarily catalyzed by sulfur-oxidizing bacteria (SOB). Little is known about microbial sulfur cycling in circumneutral pH mine tailing impoundment waters. Here we investigate biological sulfur oxidation over four years in a mine tailings impoundment water cap, integrating aqueous sulfur geochemistry, genome-resolved metagenomics and metatranscriptomics. The microbial community is consistently dominated by neutrophilic, chemolithoautotrophic SOB (relative abundances of ~76% in 2015, ~55% in 2016/2017 and ~60% in 2018). Results reveal two SOB strategies alternately dominate across the four years, influencing acid generation and sulfur speciation. Under oxic conditions, novel Halothiobacillus drive lower pH conditions (as low as 4.3) and lower [S2O32-] via the complete Sox pathway coupled to O2. Under anoxic conditions, Thiobacillus spp. dominate in activity, via the incomplete Sox and rDSR pathways coupled to NO3-, resulting in higher [S2O32-] and no net significant acidity generation. This study provides genomic evidence explaining acidity generation and thiosulfate accumulation patterns in a circumneutral mine tailing impoundment and has significant environmental applications in preventing the discharge of sulfur compounds that can impact downstream environments. These insights illuminate opportunities for in situ biotreatment of reduced sulfur compounds and prediction of acidification events using gene-based monitoring and in situ RNA detection.
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Affiliation(s)
- Kelly J Whaley-Martin
- University of Toronto, Toronto, ON, Canada
- Environmental Resources management (ERM), Toronto, ON, Canada
| | - Lin-Xing Chen
- Department of Earth and Planetary Science, University of California, Berkeley, CA, USA
| | | | | | - Rose Kantor
- Department of Earth and Planetary Science, University of California, Berkeley, CA, USA
| | | | - Stephanie Marshall
- Environmental Resources management (ERM), Toronto, ON, Canada
- McMaster University, Hamilton, ON, Canada
| | - Sam McGarry
- Glencore, Sudbury Integrated Nickel Operations, Sudbury, ON, Canada
| | | | | | | | - Simon Apte
- CSIRO Land and Water, Clayton, NSW, Australia
| | - Jillian F Banfield
- Department of Earth and Planetary Science, University of California, Berkeley, CA, USA.
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7
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Nguyen VH, Wemheuer B, Song W, Bennett H, Palladino G, Burgsdorf I, Sizikov S, Steindler L, Webster NS, Thomas T. Functional characterization and taxonomic classification of novel gammaproteobacterial diversity in sponges. Syst Appl Microbiol 2023; 46:126401. [PMID: 36774720 DOI: 10.1016/j.syapm.2023.126401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 01/18/2023] [Accepted: 01/22/2023] [Indexed: 01/26/2023]
Abstract
Sponges harbour exceptionally diverse microbial communities, whose members are largely uncultured. The class Gammaproteobacteria often dominates the microbial communities of various sponge species, but most of its diversity remains functional and taxonomically uncharacterised. Here we reconstructed and characterised 32 metagenome-assembled genomes (MAGs) derived from three sponge species. These MAGs represent ten novel species and belong to seven orders, of which one is new. We propose nomenclature for all these taxa. These new species comprise sponge-specific bacteria with varying levels of host specificity. Functional gene profiling highlights significant differences in metabolic capabilities across the ten species, though each also often exhibited a large degree of metabolic diversity involving various nitrogen- and sulfur-based compounds. The genomic features of the ten species suggest they have evolved to form symbiotic interaction with their hosts or are well-adapted to survive within the sponge environment. These Gammaproteobacteria are proposed to scavenge substrates from the host environment, including metabolites or cellular components of the sponge. Their diverse metabolic capabilities may allow for efficient cycling of organic matter in the sponge environment, potentially to the benefit of the host and other symbionts.
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Affiliation(s)
- Viet Hung Nguyen
- Centre for Marine Science and Innovation, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Bernd Wemheuer
- Centre for Marine Science and Innovation, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Weizhi Song
- Centre for Marine Science and Innovation, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Holly Bennett
- Australian Institute of Marine Science, Townsville, Queensland, Australia; Cawthron Institute, Nelson, New Zealand
| | - Giorgia Palladino
- Centre for Marine Science and Innovation, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia; Unit of Microbiome Science and Biotechnology, Department of Pharmacy and Biotechnology, University of Bologna, via Belmeloro 6, 40126 Bologna, Italy
| | | | | | | | - Nicole S Webster
- Australian Institute of Marine Science, Townsville, Queensland, Australia; Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia; Australian Antarctic Division, Kingston, Tasmania, Australia
| | - Torsten Thomas
- Centre for Marine Science and Innovation, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia.
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8
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Han S, Li Y, Gao H. Generation and Physiology of Hydrogen Sulfide and Reactive Sulfur Species in Bacteria. Antioxidants (Basel) 2022; 11:antiox11122487. [PMID: 36552695 PMCID: PMC9774590 DOI: 10.3390/antiox11122487] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 12/14/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022] Open
Abstract
Sulfur is not only one of the most abundant elements on the Earth, but it is also essential to all living organisms. As life likely began and evolved in a hydrogen sulfide (H2S)-rich environment, sulfur metabolism represents an early form of energy generation via various reactions in prokaryotes and has driven the sulfur biogeochemical cycle since. It has long been known that H2S is toxic to cells at high concentrations, but now this gaseous molecule, at the physiological level, is recognized as a signaling molecule and a regulator of critical biological processes. Recently, many metabolites of H2S, collectively called reactive sulfur species (RSS), have been gradually appreciated as having similar or divergent regulatory roles compared with H2S in living organisms, especially mammals. In prokaryotes, even in bacteria, investigations into generation and physiology of RSS remain preliminary and an understanding of the relevant biological processes is still in its infancy. Despite this, recent and exciting advances in the fields are many. Here, we discuss abiotic and biotic generation of H2S/RSS, sulfur-transforming enzymes and their functioning mechanisms, and their physiological roles as well as the sensing and regulation of H2S/RSS.
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9
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Jenner LP, Crack JC, Kurth JM, Soldánová Z, Brandt L, Sokol KP, Reisner E, Bradley JM, Dahl C, Cheesman MR, Butt JN. Reaction of Thiosulfate Dehydrogenase with a Substrate Mimic Induces Dissociation of the Cysteine Heme Ligand Giving Insights into the Mechanism of Oxidative Catalysis. J Am Chem Soc 2022; 144:18296-18304. [PMID: 36173876 PMCID: PMC9562282 DOI: 10.1021/jacs.2c06062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Thiosulfate dehydrogenases are bacterial cytochromes
that contribute
to the oxidation of inorganic sulfur. The active sites of these enzymes
contain low-spin c-type heme with Cys–/His axial ligation. However, the reduction potentials of these hemes
are several hundred mV more negative than that of the thiosulfate/tetrathionate
couple (Em, +198 mV), making it difficult
to rationalize the thiosulfate oxidizing capability. Here, we describe
the reaction of Campylobacter jejuni thiosulfate dehydrogenase (TsdA) with sulfite, an analogue of thiosulfate.
The reaction leads to stoichiometric conversion of the active site
Cys to cysteinyl sulfonate (Cα-CH2-S-SO3–) such that the protein exists in a form
closely resembling a proposed intermediate in the pathway for thiosulfate
oxidation that carries a cysteinyl thiosulfate (Cα-CH2-S-SSO3–). The active
site heme in the stable sulfonated protein displays an Em approximately 200 mV more positive than the Cys–/His-ligated state. This can explain the thiosulfate
oxidizing activity of the enzyme and allows us to propose a catalytic
mechanism for thiosulfate oxidation. Substrate-driven release of the
Cys heme ligand allows that side chain to provide the site of substrate
binding and redox transformation; the neighboring heme then simply
provides a site for electron relay to an appropriate partner. This
chemistry is distinct from that displayed by the Cys-ligated hemes
found in gas-sensing hemoproteins and in enzymes such as the cytochromes
P450. Thus, a further class of thiolate-ligated hemes is proposed,
as exemplified by the TsdA centers that have evolved to catalyze the
controlled redox transformations of inorganic oxo anions of sulfur.
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Affiliation(s)
- Leon P Jenner
- Centre for Molecular and Structural Biochemistry, School of Chemistry and School of Biological Sciences, University of East Anglia, Norwich Research Park, NorwichNR4 7TJ, United Kingdom
| | - Jason C Crack
- Centre for Molecular and Structural Biochemistry, School of Chemistry and School of Biological Sciences, University of East Anglia, Norwich Research Park, NorwichNR4 7TJ, United Kingdom
| | - Julia M Kurth
- Institut für Mikrobiologie & Biotechnologie, Friedrich Wilhelms Universität Bonn, D-53115Bonn, Germany
| | - Zuzana Soldánová
- Centre for Molecular and Structural Biochemistry, School of Chemistry and School of Biological Sciences, University of East Anglia, Norwich Research Park, NorwichNR4 7TJ, United Kingdom
| | - Linda Brandt
- Institut für Mikrobiologie & Biotechnologie, Friedrich Wilhelms Universität Bonn, D-53115Bonn, Germany
| | - Katarzyna P Sokol
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, CambridgeCB2 1EW, United Kingdom
| | - Erwin Reisner
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, CambridgeCB2 1EW, United Kingdom
| | - Justin M Bradley
- Centre for Molecular and Structural Biochemistry, School of Chemistry and School of Biological Sciences, University of East Anglia, Norwich Research Park, NorwichNR4 7TJ, United Kingdom
| | - Christiane Dahl
- Institut für Mikrobiologie & Biotechnologie, Friedrich Wilhelms Universität Bonn, D-53115Bonn, Germany
| | - Myles R Cheesman
- Centre for Molecular and Structural Biochemistry, School of Chemistry and School of Biological Sciences, University of East Anglia, Norwich Research Park, NorwichNR4 7TJ, United Kingdom
| | - Julea N Butt
- Centre for Molecular and Structural Biochemistry, School of Chemistry and School of Biological Sciences, University of East Anglia, Norwich Research Park, NorwichNR4 7TJ, United Kingdom
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10
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Du R, Gao D, Wang Y, Liu L, Cheng J, Liu J, Zhang XH, Yu M. Heterotrophic Sulfur Oxidation of Halomonas titanicae SOB56 and Its Habitat Adaptation to the Hydrothermal Environment. Front Microbiol 2022; 13:888833. [PMID: 35774465 PMCID: PMC9237845 DOI: 10.3389/fmicb.2022.888833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 05/24/2022] [Indexed: 11/23/2022] Open
Abstract
Halomonas bacteria are ubiquitous in global marine environments, however, their sulfur-oxidizing abilities and survival adaptations in hydrothermal environments are not well understood. In this study, we characterized the sulfur oxidation ability and metabolic mechanisms of Halomonas titanicae SOB56, which was isolated from the sediment of the Tangyin hydrothermal field in the Southern Okinawa Trough. Physiological characterizations showed that it is a heterotrophic sulfur-oxidizing bacterium that can oxidize thiosulfate to tetrathionate, with the Na2S2O3 degradation reaching 94.86%. Two potential thiosulfate dehydrogenase-related genes, tsdA and tsdB, were identified as encoding key catalytic enzymes, and their expression levels in strain SOB56 were significantly upregulated. Nine of fifteen examined Halomonas genomes possess TsdA- and TsdB-homologous proteins, whose amino acid sequences have two typical Cys-X2-Cys-His heme-binding regions. Moreover, the thiosulfate oxidation process in H. titanicae SOB56 might be regulated by quorum sensing, and autoinducer-2 synthesis protein LuxS was identified in its genome. Regarding the mechanisms underlying adaptation to hydrothermal environment, strain SOB56 was capable of forming biofilms and producing EPS. In addition, genes related to complete flagellum assembly system, various signal transduction histidine kinases, heavy metal transporters, anaerobic respiration, and variable osmotic stress regulation were also identified. Our results shed light on the potential functions of heterotrophic Halomonas bacteria in hydrothermal sulfur cycle and revealed possible adaptations for living at deep-sea hydrothermal fields by H. titanicae SOB56.
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Affiliation(s)
- Rui Du
- College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, China
- Laboratory for Marine Ecology and Environmental Science, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China
| | - Di Gao
- College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, China
| | - Yiting Wang
- College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, China
| | - Lijun Liu
- College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, China
| | - Jingguang Cheng
- College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, China
| | - Jiwen Liu
- College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, China
- Laboratory for Marine Ecology and Environmental Science, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China
| | - Xiao-Hua Zhang
- College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, China
- Laboratory for Marine Ecology and Environmental Science, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China
| | - Min Yu
- College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, China
- Laboratory for Marine Ecology and Environmental Science, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China
- *Correspondence: Min Yu,
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11
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Complete genome sequence of Pseudomonas stutzeri S116 owning bifunctional catalysis provides insights into affecting performance of microbial fuel cells. BMC Microbiol 2022; 22:137. [PMID: 35590268 PMCID: PMC9118636 DOI: 10.1186/s12866-022-02552-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 05/03/2022] [Indexed: 12/03/2022] Open
Abstract
Background Pseudomonas stutzeri S116 is a sulfur-oxidizing bacteria isolated from marine sludge. It exhibited excellent electricity generation as bioanode and biocathode applied in microbial fuel cells (MFCs). Complete genome sequencing of P. stutzeri and cyclic voltammetry method were performed to reveal its mechanism in microbial fuel cells system. Results This study indicated that the MFCs generated a maximum output voltage of 254.2 mV and 226.0 mV, and maximum power density of 765 mW/m2 and 656.6 mW/m2 respectively. Complete genome sequencing of P. stutzeri S116 was performed to indicate that most function genes showed high similarities with P. stutzeri, and its primary annotations were associated with energy production and conversion (6.84%), amino acid transport and metabolism (6.82%) and inorganic ion transport and metabolism (6.77%). Homology of 36 genes involved in oxidative phosphorylation was detected, which suggests the strain S116 possesses an integrated electron transport chain. Additionally, many genes encoding pilus-assembly proteins and redox mediators (riboflavin and phenazine) were detected in the databases. Thiosulfate oxidization and dissimilatory nitrate reduction were annotated in the sulfur metabolism pathway and nitrogen metabolism pathway, respectively. Gene function analysis and cyclic voltammetry indicated that P. stutzeri probably possesses cellular machinery such as cytochrome c and redox mediators and can perform extracellular electron transfer and produce electricity in MFCs. Conclusion The redox mediators secreted by P. stutzeri S116 were probably responsible for performance of MFCs. The critical genes and metabolic pathways involved in thiosulfate oxide and nitrate reduction were detected, which indicated that the strain can treat wastewater containing sulfide and nitrite efficiently. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-022-02552-8.
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12
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Wei D, Liu L, Shi J, Yan W, Chen X, Li X. Biodesulfurization of thiosulfate by a Pseudomonas strain PSP1 and the investigation of underlying metabolic mechanisms. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:33764-33773. [PMID: 35029825 DOI: 10.1007/s11356-022-18648-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 01/09/2022] [Indexed: 06/14/2023]
Abstract
The increasing public expectations for good air quality have necessitated the development of biodeodorization technology. Among different malodorous pollutants, H2S has attracted extensive attention and diverse biodesulfurization technology has been developed for efficient H2S removal. In this study, a novel heterotrophic Pseudomonas strain, PSP1, was isolated from biogas slurry and its biodesulfurization ability was investigated. Culture conditions of 30 °C and 200 rpm were determined as the optimal for both cell growth and thiosulfate conversion. Under such conditions, the highest OD600 value was observed as 6.74 and 50 mM thiosulfate within 10 h. PSP1 was found to convert thiosulfate to sulfane which could be decomposed into elemental sulfur and therefore achieved desulfurization. However, this process was relatively weak as more than 60% thiosulfate was converted into soluble tetrathionate. The whole genome sequencing and functional annotation identified the genes in PSP1 associated with sulfur metabolism and the RT-qPCR analysis quantified the expression level of corresponding genes. The expression level of tsdA, which was responsible for tetrathionate production, was around 60 folds higher than genes for sulfane production (e.g. TST1, cysI). Further research would focus on the enhancement of sulfane production pathway through metabolic engineering tools.
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Affiliation(s)
- Dong Wei
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201210, China
- Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai, 200241, China
| | - Li Liu
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201210, China
- Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai, 200241, China
| | - Jiping Shi
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201210, China
- Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai, 200241, China
| | - Weizhi Yan
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201210, China
- Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai, 200241, China
| | - Xiaojia Chen
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201210, China
| | - Xiang Li
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201210, China.
- Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai, 200241, China.
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13
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Allochromatium tepidum, sp. nov., a hot spring species of purple sulfur bacteria. Arch Microbiol 2022; 204:115. [PMID: 34984587 DOI: 10.1007/s00203-021-02715-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 11/16/2021] [Accepted: 11/18/2021] [Indexed: 12/30/2022]
Abstract
We describe a new species of purple sulfur bacteria (Chromatiaceae, anoxygenic phototrophic bacteria) isolated from a microbial mat in the sulfidic geothermal outflow of a hot spring in Rotorua, New Zealand. This phototroph, designated as strain NZ, grew optimally near 45 °C but did not show an absorption maximum at 915 nm for the light-harvesting-reaction center core complex (LH1-RC) characteristic of other thermophilic purple sulfur bacteria. Strain NZ had a similar carotenoid composition as Thermochromatium tepidum, but unlike Tch. tepidum, grew photoheterotrophically on acetate in the absence of sulfide and metabolized thiosulfate. The genome of strain NZ was significantly larger than that of Tch. tepidum but slightly smaller than that of Allochromatium vinosum. Strain NZ was phylogenetically more closely related to mesophilic purple sulfur bacteria of the genus Allochromatium than to Tch. tepidum. This conclusion was reached from phylogenetic analyses of strain NZ genes encoding 16S rRNA and the photosynthetic functional gene pufM, from phylogenetic analyses of entire genomes, and from a phylogenetic tree constructed from the concatenated sequence of 1090 orthologous proteins. Moreover, average nucleotide identities and digital DNA:DNA hybridizations of the strain NZ genome against those of related species of Chromatiaceae supported the phylogenetic analyses. From this collection of properties, we describe strain NZ here as the first thermophilic species of the genus Allochromatium, Allochromatium tepidum NZT, sp. nov.
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14
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A new regime of heme-dependent aromatic oxygenase superfamily. Proc Natl Acad Sci U S A 2021; 118:2106561118. [PMID: 34667125 DOI: 10.1073/pnas.2106561118] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/31/2021] [Indexed: 12/14/2022] Open
Abstract
Two histidine-ligated heme-dependent monooxygenase proteins, TyrH and SfmD, have recently been found to resemble enzymes from the dioxygenase superfamily currently named after tryptophan 2,3-dioxygenase (TDO), that is, the TDO superfamily. These latest findings prompted us to revisit the structure and function of the superfamily. The enzymes in this superfamily share a similar core architecture and a histidine-ligated heme. Their primary functions are to promote O-atom transfer to an aromatic metabolite. TDO and indoleamine 2,3-dioxygenase (IDO), the founding members, promote dioxygenation through a two-step monooxygenation pathway. However, the new members of the superfamily, including PrnB, SfmD, TyrH, and MarE, expand its boundaries and mediate monooxygenation on a broader set of aromatic substrates. We found that the enlarged superfamily contains eight clades of proteins. Overall, this protein group is a more sizeable, structure-based, histidine-ligated heme-dependent, and functionally diverse superfamily for aromatics oxidation. The concept of TDO superfamily or heme-dependent dioxygenase superfamily is no longer appropriate for defining this growing superfamily. Hence, there is a pressing need to redefine it as a heme-dependent aromatic oxygenase (HDAO) superfamily. The revised concept puts HDAO in the context of thiol-ligated heme-based enzymes alongside cytochrome P450 and peroxygenase. It will update what we understand about the choice of heme axial ligand. Hemoproteins may not be as stringent about the type of axial ligand for oxygenation, although thiolate-ligated hemes (P450s and peroxygenases) more frequently catalyze oxygenation reactions. Histidine-ligated hemes found in HDAO enzymes can likewise mediate oxygenation when confronted with a proper substrate.
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15
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Alam M, Fernandes S, Mandal S, Rameez MJ, Bhattacharya S, Peketi A, Mazumdar A, Ghosh W. 34S enrichment as a signature of thiosulfate oxidation in the "Proteobacteria". FEMS Microbiol Lett 2021; 368:6307019. [PMID: 34151347 DOI: 10.1093/femsle/fnab073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 06/17/2021] [Indexed: 12/17/2022] Open
Abstract
Kinetics of thiosulfate oxidation, product and intermediate formation, and 34S fractionation, were studied for the members of Alphaproteobacteria Paracoccus sp. SMMA5 and Mesorhizobium thiogangeticum SJTT, the Betaproteobacteria member Pusillimonas ginsengisoli SBO3, and the Acidithiobacillia member Thermithiobacillus sp. SMMA2, during chemolithoautotrophic growth in minimal salts media supplemented with 20 mM thiosulfate. The two Alphaproteobacteria oxidized thiosulfate directly to sulfate, progressively enriching the end-product with 34S; Δ34Sthiosulfate-sulfate values recorded at the end of the two processes (when no thiosulfate was oxidized any further) were -2.9‰ and -3.5‰, respectively. Pusillimonas ginsengisoli SBO3 and Thermithiobacillus sp. SMMA2, on the other hand, oxidized thiosulfate to sulfate via tetrathionate intermediate formation, with progressive 34S enrichment in the end-product sulfate throughout the incubation period; Δ34Sthiosulfate-sulfate, at the end of the two processes (when no further oxidation took place), reached -3.5‰ and -3.8‰, respectively. Based on similar 34S fractionation patterns recorded previously during thiosulfate oxidation by strains of Paracoccus pantotrophus, Advenella kashmirensis and Hydrogenovibrio crunogenus, it was concluded that progressive reverse fractionation, enriching the end-product sulfate with 34S, could be a characteristic signature of bacterial thiosulfate oxidation.
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Affiliation(s)
- Masrure Alam
- Department of Microbiology, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata-700054, West Bengal, India
| | - Svetlana Fernandes
- Gas Hydrate Research Group, Geological Oceanography, CSIR-National Institute of Oceanography, Dona Paula, Goa-403004, India
| | - Subhrangshu Mandal
- Department of Microbiology, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata-700054, West Bengal, India
| | - Maida Jameela Rameez
- Department of Microbiology, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata-700054, West Bengal, India
| | - Sabyasachi Bhattacharya
- Department of Microbiology, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata-700054, West Bengal, India
| | - Aditya Peketi
- Gas Hydrate Research Group, Geological Oceanography, CSIR-National Institute of Oceanography, Dona Paula, Goa-403004, India
| | - Aninda Mazumdar
- Gas Hydrate Research Group, Geological Oceanography, CSIR-National Institute of Oceanography, Dona Paula, Goa-403004, India
| | - Wriddhiman Ghosh
- Department of Microbiology, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata-700054, West Bengal, India
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16
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Wang L, Shao Z. Aerobic Denitrification and Heterotrophic Sulfur Oxidation in the Genus Halomonas Revealed by Six Novel Species Characterizations and Genome-Based Analysis. Front Microbiol 2021; 12:652766. [PMID: 33815342 PMCID: PMC8014003 DOI: 10.3389/fmicb.2021.652766] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 02/09/2021] [Indexed: 11/16/2022] Open
Abstract
Bacteria of Halomonas are widely distributed in various environments and play a substantial role in the nutrient cycle. In this report, 14 strains capable of aerobic denitrification and heterotrophic sulfur oxidation were isolated from different habitats. Based on the phenotypic, genotypic, and chemotaxonomic analyses, these strains were considered to represent six novel species of the genus Halomonas, for which the names Halomonas zhangzhouensis sp. nov. type strain CXT3-11T ( = MCCC 1A11036T = KCTC 72087T), Halomonas aerodenitrificans sp. nov. CYD-9T ( = MCCC 1A11058T = KCTC 72088T), Halomonas sulfidoxydans sp. nov. CYN-1-2T ( = MCCC 1A11059T = KCTC 72089T), Halomonas ethanolica sp. nov. CYT3-1-1T ( = MCCC 1A11081T = KCTC 72090T), Halomonas sulfidivorans sp. nov. NLG_F1ET ( = MCCC 1A13718T = KCTC 72091T), and Halomonas tianxiuensis sp. nov. BC-M4-5T ( = MCCC 1A14433T = KCTC 72092T) are proposed. Intriguingly, they formed a unique group with 11 other species designated as the "H. desiderata group." To better understand their featured metabolisms, genes involved in denitrification and sulfur oxidation were analyzed, along with 193 other available genomes of the whole genus. Consistently, complete denitrification pathways were confirmed in the "H. desiderata group," in which napA, narG, nirS, norB, and nosZ genes coexist. Their nitrite reductase NirS formed a unique evolutionary lineage, distinguished from other denitrifiers in Halomonas. In addition, diverse occurrence patterns of denitrification genes were also observed in different phylogenetic clades of Halomonas. With respect to sulfur oxidation, fccAB genes involved in sulfide oxidation commonly exist in the "H. desiderata group," while sqr genes are diverse and can be found in more species; sqr genes co-occurred with fccAB in eight strains of this study, contributing to more active sulfide oxidation. Besides, the tsdA gene, which encodes an enzyme that oxidizes thiosulfate to tetrathionate, is ubiquitous in the genus Halomonas. The widespread presence of sqr/fccAB, pdo, and tsdA in Halomonas suggests that many Halomonas spp. can act as heterotrophic sulfur oxidizers. These results provide comprehensive insights into the potential of denitrification and sulfur oxidation in the whole genus of Halomonas. With regard to the global distribution of Halomonas, this report implies their unneglectable role in the biogeochemical cycle.
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Affiliation(s)
- Liping Wang
- School of Environment, Harbin Institute of Technology, Harbin, China
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, State Key Laboratory Breeding Base of Marine Genetic Resources, Fujian Key Laboratory of Marine Genetic Resources, Xiamen, China
| | - Zongze Shao
- School of Environment, Harbin Institute of Technology, Harbin, China
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, State Key Laboratory Breeding Base of Marine Genetic Resources, Fujian Key Laboratory of Marine Genetic Resources, Xiamen, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
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17
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Shin I, Davis I, Nieves-Merced K, Wang Y, McHardy S, Liu A. A novel catalytic heme cofactor in SfmD with a single thioether bond and a bis-His ligand set revealed by a de novo crystal structural and spectroscopic study. Chem Sci 2021; 12:3984-3998. [PMID: 34163669 PMCID: PMC8179489 DOI: 10.1039/d0sc06369j] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 01/21/2021] [Indexed: 12/13/2022] Open
Abstract
SfmD is a heme-dependent enzyme in the biosynthetic pathway of saframycin A. Here, we present a 1.78 Å resolution de novo crystal structure of SfmD, which unveils a novel heme cofactor attached to the protein with an unusual Hx n HxxxC motif (n ∼ 38). This heme cofactor is unique in two respects. It contains a single thioether bond in a cysteine-vinyl link with Cys317, and the ferric heme has two axial protein ligands, i.e., His274 and His313. We demonstrated that SfmD heme is catalytically active and can utilize dioxygen and ascorbate for a single-oxygen insertion into 3-methyl-l-tyrosine. Catalytic assays using ascorbate derivatives revealed the functional groups of ascorbate essential to its function as a cosubstrate. Abolishing the thioether linkage through mutation of Cys317 resulted in catalytically inactive SfmD variants. EPR and optical data revealed that the heme center undergoes a substantial conformational change with one axial histidine ligand dissociating from the iron ion in response to substrate 3-methyl-l-tyrosine binding or chemical reduction by a reducing agent, such as the cosubstrate ascorbate. The labile axial ligand was identified as His274 through redox-linked structural determinations. Together, identifying an unusual heme cofactor with a previously unknown heme-binding motif for a monooxygenase activity and the structural similarity of SfmD to the members of the heme-based tryptophan dioxygenase superfamily will broaden understanding of heme chemistry.
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Affiliation(s)
- Inchul Shin
- Department of Chemistry, The University of Texas at San Antonio One UTSA Circle Texas 78249 USA
| | - Ian Davis
- Department of Chemistry, The University of Texas at San Antonio One UTSA Circle Texas 78249 USA
| | - Karinel Nieves-Merced
- Department of Chemistry, The University of Texas at San Antonio One UTSA Circle Texas 78249 USA
- Center for Innovative Drug Discovery, The University of Texas at San Antonio One UTSA Circle Texas 78249 USA
| | - Yifan Wang
- Department of Chemistry, The University of Texas at San Antonio One UTSA Circle Texas 78249 USA
| | - Stanton McHardy
- Department of Chemistry, The University of Texas at San Antonio One UTSA Circle Texas 78249 USA
- Center for Innovative Drug Discovery, The University of Texas at San Antonio One UTSA Circle Texas 78249 USA
| | - Aimin Liu
- Department of Chemistry, The University of Texas at San Antonio One UTSA Circle Texas 78249 USA
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18
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Pfanzagl V, Beale JH, Michlits H, Schmidt D, Gabler T, Obinger C, Djinović-Carugo K, Hofbauer S. X-ray-induced photoreduction of heme metal centers rapidly induces active-site perturbations in a protein-independent manner. J Biol Chem 2020; 295:13488-13501. [PMID: 32723869 DOI: 10.1074/jbc.ra120.014087] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 07/24/2020] [Indexed: 12/31/2022] Open
Abstract
Since the advent of protein crystallography, atomic-level macromolecular structures have provided a basis to understand biological function. Enzymologists use detailed structural insights on ligand coordination, interatomic distances, and positioning of catalytic amino acids to rationalize the underlying electronic reaction mechanisms. Often the proteins in question catalyze redox reactions using metal cofactors that are explicitly intertwined with their function. In these cases, the exact nature of the coordination sphere and the oxidation state of the metal is of utmost importance. Unfortunately, the redox-active nature of metal cofactors makes them especially susceptible to photoreduction, meaning that information obtained by photoreducing X-ray sources about the environment of the cofactor is the least trustworthy part of the structure. In this work we directly compare the kinetics of photoreduction of six different heme protein crystal species by X-ray radiation. We show that a dose of ∼40 kilograys already yields 50% ferrous iron in a heme protein crystal. We also demonstrate that the kinetics of photoreduction are completely independent from variables unique to the different samples tested. The photoreduction-induced structural rearrangements around the metal cofactors have to be considered when biochemical data of ferric proteins are rationalized by constraints derived from crystal structures of reduced enzymes.
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Affiliation(s)
- Vera Pfanzagl
- Department of Chemistry, Institute of Biochemistry, BOKU-University of Natural Resources and Life Sciences, Vienna, Austria.
| | | | - Hanna Michlits
- Department of Chemistry, Institute of Biochemistry, BOKU-University of Natural Resources and Life Sciences, Vienna, Austria
| | - Daniel Schmidt
- Department of Chemistry, Institute of Biochemistry, BOKU-University of Natural Resources and Life Sciences, Vienna, Austria
| | - Thomas Gabler
- Department of Chemistry, Institute of Biochemistry, BOKU-University of Natural Resources and Life Sciences, Vienna, Austria
| | - Christian Obinger
- Department of Chemistry, Institute of Biochemistry, BOKU-University of Natural Resources and Life Sciences, Vienna, Austria
| | - Kristina Djinović-Carugo
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Vienna, Austria; Department of Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Stefan Hofbauer
- Department of Chemistry, Institute of Biochemistry, BOKU-University of Natural Resources and Life Sciences, Vienna, Austria.
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19
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Zhang J, Liu R, Xi S, Cai R, Zhang X, Sun C. A novel bacterial thiosulfate oxidation pathway provides a new clue about the formation of zero-valent sulfur in deep sea. ISME JOURNAL 2020; 14:2261-2274. [PMID: 32457501 PMCID: PMC7608252 DOI: 10.1038/s41396-020-0684-5] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 05/06/2020] [Accepted: 05/12/2020] [Indexed: 11/09/2022]
Abstract
Zero-valent sulfur (ZVS) has been shown to be a major sulfur intermediate in the deep-sea cold seep of the South China Sea based on our previous work, however, the microbial contribution to the formation of ZVS in cold seep has remained unclear. Here, we describe a novel thiosulfate oxidation pathway discovered in the deep-sea cold seep bacterium Erythrobacter flavus 21–3, which provides a new clue about the formation of ZVS. Electronic microscopy, energy-dispersive, and Raman spectra were used to confirm that E. flavus 21–3 effectively converts thiosulfate to ZVS. We next used a combined proteomic and genetic method to identify thiosulfate dehydrogenase (TsdA) and thiosulfohydrolase (SoxB) playing key roles in the conversion of thiosulfate to ZVS. Stoichiometric results of different sulfur intermediates further clarify the function of TsdA in converting thiosulfate to tetrathionate (−O3S–S–S–SO3−), SoxB in liberating sulfone from tetrathionate to form ZVS and sulfur dioxygenases (SdoA/SdoB) in oxidizing ZVS to sulfite under some conditions. Notably, homologs of TsdA, SoxB, and SdoA/SdoB widely exist across the bacteria including in Erythrobacter species derived from different environments. This strongly indicates that this novel thiosulfate oxidation pathway might be frequently used by microbes and plays an important role in the biogeochemical sulfur cycle in nature.
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Affiliation(s)
- Jing Zhang
- CAS Key Laboratory of Experimental Marine Biology & Center of Deep Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,College of Earth Science, University of Chinese Academy of Sciences, Beijing, China.,Center of Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
| | - Rui Liu
- CAS Key Laboratory of Experimental Marine Biology & Center of Deep Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Center of Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
| | - Shichuan Xi
- College of Earth Science, University of Chinese Academy of Sciences, Beijing, China.,Center of Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China.,CAS Key Laboratory of Marine Geology and Environment & Center of Deep Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | - Ruining Cai
- CAS Key Laboratory of Experimental Marine Biology & Center of Deep Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,College of Earth Science, University of Chinese Academy of Sciences, Beijing, China.,Center of Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
| | - Xin Zhang
- Center of Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China.,CAS Key Laboratory of Marine Geology and Environment & Center of Deep Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | - Chaomin Sun
- CAS Key Laboratory of Experimental Marine Biology & Center of Deep Sea Research, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China. .,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China. .,Center of Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China.
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20
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Zuccarello L, Berthomieu C, Boussac A, Brubach JB, Díaz-Moreno I, Díaz Quintana AJ, Hienerwadel R. Protonation of the Cysteine Axial Ligand Investigated in His/Cys c-Type Cytochrome by UV-Vis and Mid- and Far-IR Spectroscopy. J Phys Chem Lett 2020; 11:4198-4205. [PMID: 32364390 DOI: 10.1021/acs.jpclett.0c01016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
His/Cys coordination was recently found in several c-type cytochromes, which could act as sensors, in electron transport or in regulation. Toward a better understanding of Cys function and reactivity in these cytochromes, we compare cytochrome c6 (c6wt) from the cyanobacterium Nostoc PCC 7120 with its Met58Cys mutant. We probe the axial ligands and heme properties by combining visible and mid- to far-FTIR difference spectroscopies. Cys58 determines the strong negative redox potential and pH dependence of M58C (EmM58C = -375 mV, versus Emc6wt = +339 mV). Mid-IR (notably Cys ν(SH), His ν(C5N1), heme δ(CmH)) and far-IR (ν(Fe(II)-His), ν(His-Fe(III)-Cys)) markers of the heme and ligands show that Cys58 remains a strong thiolate ligand of reduced Met58Cys at alkaline pH, while it is protonated at pH 7.5, is stabilized by a strong hydrogen bonding interaction, and weakly interacts with Fe(II). These data provide a benchmark for further analysis of c-type cytochromes with natural His/Cys coordination.
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Affiliation(s)
- Lidia Zuccarello
- CEA, CNRS, Aix Marseille Univ., BIAM, Interactions Protéine Métal UMR 7265, 13108 Saint Paul-Lez-Durance, France
- Aix Marseille Univ., CEA, CNRS, BIAM, Luminy Genetics and Biophysic of Plants, UMR 7265, 13288 Marseille Cedex, France
| | - Catherine Berthomieu
- CEA, CNRS, Aix Marseille Univ., BIAM, Interactions Protéine Métal UMR 7265, 13108 Saint Paul-Lez-Durance, France
| | - Alain Boussac
- I2BC, UMR CNRS 9198, CEA Saclay, 91191 Gif-sur-Yvette, France
| | - Jean-Blaise Brubach
- Synchrotron SOLEIL, AILES Beamline, L'Orme des Merisier, Saint-Aubin, BP 48, F-91192 Gif-sur-Yvette Cedex, France
| | - Irene Díaz-Moreno
- Instituto de Investigaciones Químicas (IIQ), Centro de Investigaciones Científicas Isla de la Cartuja (cicCartuja), Universidad de Sevilla - Consejo Superior de Investigaciones Científicas (CSIC), Avda. Américo Vespucio 49, Sevilla 41092, Spain
| | - Antonio J Díaz Quintana
- Instituto de Investigaciones Químicas (IIQ), Centro de Investigaciones Científicas Isla de la Cartuja (cicCartuja), Universidad de Sevilla - Consejo Superior de Investigaciones Científicas (CSIC), Avda. Américo Vespucio 49, Sevilla 41092, Spain
| | - Rainer Hienerwadel
- Aix Marseille Univ., CEA, CNRS, BIAM, Luminy Genetics and Biophysic of Plants, UMR 7265, 13288 Marseille Cedex, France
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21
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Mandal S, Rameez MJ, Chatterjee S, Sarkar J, Pyne P, Bhattacharya S, Shaw R, Ghosh W. Molecular mechanism of sulfur chemolithotrophy in the betaproteobacterium Pusillimonas ginsengisoli SBSA. MICROBIOLOGY-SGM 2020; 166:386-397. [PMID: 31999239 DOI: 10.1099/mic.0.000890] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Chemolithotrophic sulfur oxidation represents a significant part of the biogeochemical cycling of this element. Due to its long evolutionary history, this ancient metabolism is well known for its extensive mechanistic and phylogenetic diversification across a diverse taxonomic spectrum. Here we carried out whole-genome sequencing and analysis of a new betaproteobacterial isolate, Pusillimonas ginsengisoli SBSA, which is found to oxidize thiosulfate via the formation of tetrathionate as an intermediate. The 4.7 Mb SBSA genome was found to encompass a soxCDYZAXOB operon, plus single thiosulfate dehydrogenase (tsdA) and sulfite : acceptor oxidoreductase (sorAB) genes. Recombination-based knockout of tsdA revealed that the entire thiosulfate is first converted to tetrathionate by the activity of thiosulfate dehydrogenase (TsdA) and the Sox pathway is not functional in this bacterium despite the presence of all necessary sox genes. The ∆soxYZ and ∆soxXA knockout mutants exhibited a wild-type-like phenotype for thiosulfate/tetrathionate oxidation, whereas ∆soxB, ∆soxCD and soxO::KanR mutants only oxidized thiosulfate up to tetrathionate intermediate and had complete impairment in tetrathionate oxidation. The substrate-dependent O2 consumption rate of whole cells and the sulfur-oxidizing enzyme activities of cell-free extracts, measured in the presence/absence of thiol inhibitors/glutathione, indicated that glutathione plays a key role in SBSA tetrathionate oxidation. The present findings collectively indicate that the potential glutathione : tetrathionate coupling in P. ginsengisoli involves a novel enzymatic component, which is different from the dual-functional thiol dehydrotransferase (ThdT), while subsequent oxidation of the sulfur intermediates produced (e.g. glutathione : sulfodisulfane molecules) may proceed via the iterative action of soxBCD .
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Affiliation(s)
- Subhrangshu Mandal
- Department of Microbiology, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata-700054, India
| | - Moidu Jameela Rameez
- Department of Microbiology, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata-700054, India
| | - Sumit Chatterjee
- Department of Microbiology, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata-700054, India
| | - Jagannath Sarkar
- Department of Microbiology, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata-700054, India
| | - Prosenjit Pyne
- Present address: National Institute of Cholera and Enteric Diseases (NICED), P- C.I.T. Scheme XM, Beleghata, 33, CIT Rd, Beleghata, Kolkata - 700054, India.,Department of Microbiology, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata-700054, India
| | | | - Rahul Shaw
- Department of Microbiology, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata-700054, India
| | - Wriddhiman Ghosh
- Department of Microbiology, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata-700054, India
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22
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Rameez MJ, Pyne P, Mandal S, Chatterjee S, Alam M, Bhattacharya S, Mondal N, Sarkar J, Ghosh W. Two pathways for thiosulfate oxidation in the alphaproteobacterial chemolithotroph Paracoccus thiocyanatus SST. Microbiol Res 2019; 230:126345. [PMID: 31585234 DOI: 10.1016/j.micres.2019.126345] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 09/08/2019] [Accepted: 09/21/2019] [Indexed: 02/02/2023]
Abstract
Chemolithotrophic bacteria oxidize various sulfur species for energy and electrons, thereby operationalizing biogeochemical sulfur cycles in nature. The best-studied pathway of bacterial sulfur-chemolithotrophy involves direct oxidation of thiosulfate (S2O32-) to sulfate (SO42-) without any free intermediate. This pathway mediated by SoxXAYZBCD is apparently the exclusive mechanism of thiosulfate oxidation in facultatively chemolithotrophic alphaproteobacteria. Here we explore the molecular mechanisms of sulfur oxidation in the thiosulfate- and tetrathionate(S4O62-)-oxidizing alphaproteobacterium Paracoccus thiocyanatus SST, and compare them with the prototypical Sox process of Paracoccus pantotrophus. Our results reveal a unique case where an alphaproteobacterium has Sox as its secondary pathway of thiosulfate oxidation converting ∼10% of the thiosulfate supplied, whilst ∼90% of the substrate is oxidized via a pathway that produces tetrathionate as an intermediate. Sulfur oxidation kinetics of a deletion mutant showed that thiosulfate-to-tetrathionate conversion, in SST, is catalyzed by a thiosulfate dehydrogenase (TsdA) homolog that has far-higher substrate-affinity than the Sox system of this bacterium, which in turn is also less efficient than the P. pantotrophus Sox. Deletion of soxB abolished sulfate-formation from thiosulfate/tetrathionate, while thiosulfate-to-tetrathionate conversion remained unperturbed. Physiological studies revealed the involvement of glutathione in SST tetrathionate oxidation. However, zero impact of the insertional mutation of a thiol dehydrotransferase (thdT) homolog, together with the absence of sulfite as an intermediate, indicated that SST tetrathionate oxidation is mechanistically novel, and distinct from its betaproteobacterial counterpart mediated by glutathione, ThdT, SoxBCD and sulfite:acceptor oxidoreductase. The present findings highlight extensive functional diversification of sulfur-oxidizing enzymes across phylogenetically close, as well as distant, bacteria.
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Affiliation(s)
- Moidu Jameela Rameez
- Department of Microbiology, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata, 700054, India
| | - Prosenjit Pyne
- Department of Microbiology, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata, 700054, India
| | - Subhrangshu Mandal
- Department of Microbiology, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata, 700054, India
| | - Sumit Chatterjee
- Department of Microbiology, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata, 700054, India
| | - Masrure Alam
- Department of Microbiology, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata, 700054, India
| | | | - Nibendu Mondal
- Department of Microbiology, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata, 700054, India
| | - Jagannath Sarkar
- Department of Microbiology, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata, 700054, India
| | - Wriddhiman Ghosh
- Department of Microbiology, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata, 700054, India.
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23
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Jenner LP, Kurth JM, van Helmont S, Sokol KP, Reisner E, Dahl C, Bradley JM, Butt JN, Cheesman MR. Heme ligation and redox chemistry in two bacterial thiosulfate dehydrogenase (TsdA) enzymes. J Biol Chem 2019; 294:18002-18014. [PMID: 31467084 PMCID: PMC6879331 DOI: 10.1074/jbc.ra119.010084] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 08/26/2019] [Indexed: 01/04/2023] Open
Abstract
Thiosulfate dehydrogenases (TsdAs) are bidirectional bacterial di-heme enzymes that catalyze the interconversion of tetrathionate and thiosulfate at measurable rates in both directions. In contrast to our knowledge of TsdA activities, information on the redox properties in the absence of substrates is rather scant. To address this deficit, we combined magnetic CD (MCD) spectroscopy and protein film electrochemistry (PFE) in a study to resolve heme ligation and redox chemistry in two representative TsdAs. We examined the TsdAs from Campylobacter jejuni, a microaerobic human pathogen, and from the purple sulfur bacterium Allochromatium vinosum. In these organisms, the enzyme functions as a tetrathionate reductase and a thiosulfate oxidase, respectively. The active site Heme 1 in both enzymes has His/Cys ligation in the ferric and ferrous states and the midpoint potentials (Em) of the corresponding redox transformations are similar, −185 mV versus standard hydrogen electrode (SHE). However, fundamental differences are observed in the properties of the second, electron transferring, Heme 2. In C. jejuni, TsdA Heme 2 has His/Met ligation and an Em of +172 mV. In A. vinosum TsdA, Heme 2 reduction triggers a switch from His/Lys ligation (Em, −129 mV) to His/Met (Em, +266 mV), but the rates of interconversion are such that His/Lys ligation would be retained during turnover. In summary, our findings have unambiguously assigned Em values to defined axial ligand sets in TsdAs, specified the rates of Heme 2 ligand exchange in the A. vinosum enzyme, and provided information relevant to describing their catalytic mechanism(s).
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Affiliation(s)
- Leon P Jenner
- Centre for Molecular and Structural Biochemistry, School of Chemistry and School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Julia M Kurth
- Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich Wilhelms Universität Bonn, D-53115 Bonn, Germany
| | - Sebastian van Helmont
- Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich Wilhelms Universität Bonn, D-53115 Bonn, Germany
| | - Katarzyna P Sokol
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Erwin Reisner
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Christiane Dahl
- Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich Wilhelms Universität Bonn, D-53115 Bonn, Germany
| | - Justin M Bradley
- Centre for Molecular and Structural Biochemistry, School of Chemistry and School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Julea N Butt
- Centre for Molecular and Structural Biochemistry, School of Chemistry and School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Myles R Cheesman
- Centre for Molecular and Structural Biochemistry, School of Chemistry and School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
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24
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Vavourakis CD, Mehrshad M, Balkema C, van Hall R, Andrei AŞ, Ghai R, Sorokin DY, Muyzer G. Metagenomes and metatranscriptomes shed new light on the microbial-mediated sulfur cycle in a Siberian soda lake. BMC Biol 2019; 17:69. [PMID: 31438955 PMCID: PMC6704655 DOI: 10.1186/s12915-019-0688-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 08/09/2019] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND The planetary sulfur cycle is a complex web of chemical reactions that can be microbial-mediated or can occur spontaneously in the environment, depending on the temperature and pH. Inorganic sulfur compounds can serve as energy sources for specialized prokaryotes and are important substrates for microbial growth in general. Here, we investigate dissimilatory sulfur cycling in the brine and sediments of a southwestern Siberian soda lake characterized by an extremely high pH and salinity, combining meta-omics analyses of its uniquely adapted highly diverse prokaryote communities with biogeochemical profiling to identify key microbial players and expand our understanding of sulfur cycling under haloalkaline conditions. RESULTS Peak microbial activity was found in the top 4 cm of the sediments, a layer with a steep drop in oxygen concentration and redox potential. The majority of sulfur was present as sulfate or iron sulfide. Thiosulfate was readily oxidized by microbes in the presence of oxygen, but oxidation was partially inhibited by light. We obtained 1032 metagenome-assembled genomes, including novel population genomes of characterized colorless sulfur-oxidizing bacteria (SOB), anoxygenic purple sulfur bacteria, heterotrophic SOB, and highly active lithoautotrophic sulfate reducers. Surprisingly, we discovered the potential for nitrogen fixation in a new genus of colorless SOB, carbon fixation in a new species of phototrophic Gemmatimonadetes, and elemental sulfur/sulfite reduction in the "Candidatus Woesearchaeota." Polysulfide/thiosulfate and tetrathionate reductases were actively transcribed by various (facultative) anaerobes. CONCLUSIONS The recovery of over 200 genomes that encoded enzymes capable of catalyzing key reactions in the inorganic sulfur cycle indicates complete cycling between sulfate and sulfide at moderately hypersaline and extreme alkaline conditions. Our results suggest that more taxonomic groups are involved in sulfur dissimilation than previously assumed.
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Affiliation(s)
- Charlotte D Vavourakis
- Microbial Systems Ecology, Department of Freshwater and Marine Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, 1090 GE, Amsterdam, the Netherlands
| | - Maliheh Mehrshad
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre of the Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic
| | - Cherel Balkema
- Microbial Systems Ecology, Department of Freshwater and Marine Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, 1090 GE, Amsterdam, the Netherlands
| | - Rutger van Hall
- Department of Ecosystem & Landscape Dynamics, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, the Netherlands
| | - Adrian-Ştefan Andrei
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre of the Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic
| | - Rohit Ghai
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre of the Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic
| | - Dimitry Y Sorokin
- Winogradsky Institute of Microbiology, Research Centre of Biotechnology, Russian Academy of Sciences, Moscow, Russian Federation
- Department of Biotechnology, Environmental Biotechnology, Delft University of Technology, Delft, the Netherlands
| | - Gerard Muyzer
- Microbial Systems Ecology, Department of Freshwater and Marine Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, 1090 GE, Amsterdam, the Netherlands.
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25
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Watanabe T, Kojima H, Umezawa K, Hori C, Takasuka TE, Kato Y, Fukui M. Genomes of Neutrophilic Sulfur-Oxidizing Chemolithoautotrophs Representing 9 Proteobacterial Species From 8 Genera. Front Microbiol 2019; 10:316. [PMID: 30858836 PMCID: PMC6397845 DOI: 10.3389/fmicb.2019.00316] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 02/06/2019] [Indexed: 01/08/2023] Open
Abstract
Even in the current era of metagenomics, the interpretation of nucleotide sequence data is primarily dependent on knowledge obtained from a limited number of microbes isolated in pure culture. Thus, it is of fundamental importance to expand the variety of strains available in pure culture, to make reliable connections between physiological characteristics and genomic information. In this study, two sulfur oxidizers that potentially represent two novel species were isolated and characterized. They were subjected to whole-genome sequencing together with 7 neutrophilic and chemolithoautotrophic sulfur-oxidizing bacteria. The genes for sulfur oxidation in the obtained genomes were identified and compared with those of isolated sulfur oxidizers in the classes Betaproteobacteria and Gammaproteobacteria. Although the combinations of these genes in the respective genomes are diverse, typical combinations corresponding to three types of core sulfur oxidation pathways were identified. Each pathway involves one of three specific sets of proteins, SoxCD, DsrABEFHCMKJOP, and HdrCBAHypHdrCB. All three core pathways contain the SoxXYZAB proteins, and a cytoplasmic sulfite oxidase encoded by soeABC is a conserved component in the core pathways lacking SoxCD. Phylogenetically close organisms share same core sulfur oxidation pathway, but a notable exception was observed in the family ‘Sulfuricellaceae’. In this family, some strains have either core pathway involving DsrABEFHCMKJOP or HdrCBAHypHdrCB, while others have both pathways. A proteomics analysis showed that proteins constituting the core pathways were produced at high levels. While hypothesized function of HdrCBAHypHdrCB is similar to that of Dsr system, both sets of proteins were detected with high relative abundances in the proteome of a strain possessing genes for these proteins. In addition to the genes for sulfur oxidation, those for arsenic metabolism were searched for in the sequenced genomes. As a result, two strains belonging to the families Thiobacillaceae and Sterolibacteriaceae were observed to harbor genes encoding ArxAB, a type of arsenite oxidase that has been identified in a limited number of bacteria. These findings were made with the newly obtained genomes, including those from 6 genera from which no genome sequence of an isolated organism was previously available. These genomes will serve as valuable references to interpret nucleotide sequences.
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Affiliation(s)
- Tomohiro Watanabe
- Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan.,Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Hisaya Kojima
- Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
| | - Kazuhiro Umezawa
- Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
| | - Chiaki Hori
- Research Faculty of Engineering, Hokkaido University, Sapporo, Japan
| | - Taichi E Takasuka
- Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan
| | - Yukako Kato
- Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
| | - Manabu Fukui
- Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
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26
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Wang R, Lin JQ, Liu XM, Pang X, Zhang CJ, Yang CL, Gao XY, Lin CM, Li YQ, Li Y, Lin JQ, Chen LX. Sulfur Oxidation in the Acidophilic Autotrophic Acidithiobacillus spp. Front Microbiol 2019; 9:3290. [PMID: 30687275 PMCID: PMC6335251 DOI: 10.3389/fmicb.2018.03290] [Citation(s) in RCA: 105] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 12/18/2018] [Indexed: 12/12/2022] Open
Abstract
Sulfur oxidation is an essential component of the earth's sulfur cycle. Acidithiobacillus spp. can oxidize various reduced inorganic sulfur compounds (RISCs) with high efficiency to obtain electrons for their autotrophic growth. Strains in this genus have been widely applied in bioleaching and biological desulfurization. Diverse sulfur-metabolic pathways and corresponding regulatory systems have been discovered in these acidophilic sulfur-oxidizing bacteria. The sulfur-metabolic enzymes in Acidithiobacillus spp. can be categorized as elemental sulfur oxidation enzymes (sulfur dioxygenase, sulfur oxygenase reductase, and Hdr-like complex), enzymes in thiosulfate oxidation pathways (tetrathionate intermediate thiosulfate oxidation (S4I) pathway, the sulfur oxidizing enzyme (Sox) system and thiosulfate dehydrogenase), sulfide oxidation enzymes (sulfide:quinone oxidoreductase) and sulfite oxidation pathways/enzymes. The two-component systems (TCSs) are the typical regulation elements for periplasmic thiosulfate metabolism in these autotrophic sulfur-oxidizing bacteria. Examples are RsrS/RsrR responsible for S4I pathway regulation and TspS/TspR for Sox system regulation. The proposal of sulfur metabolic and regulatory models provide new insights and overall understanding of the sulfur-metabolic processes in Acidithiobacillus spp. The future research directions and existing barriers in the bacterial sulfur metabolism are also emphasized here and the breakthroughs in these areas will accelerate the research on the sulfur oxidation in Acidithiobacillus spp. and other sulfur oxidizers.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Jian-Qun Lin
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Lin-Xu Chen
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
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27
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Shimizu T, Lengalova A, Martínek V, Martínková M. Heme: emergent roles of heme in signal transduction, functional regulation and as catalytic centres. Chem Soc Rev 2019; 48:5624-5657. [DOI: 10.1039/c9cs00268e] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Molecular mechanisms of unprecedented functions of exchangeable/labile heme and heme proteins including transcription, DNA binding, protein kinase activity, K+ channel functions, cis–trans isomerization, N–N bond formation, and other functions are described.
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Affiliation(s)
- Toru Shimizu
- Department of Biochemistry
- Faculty of Science
- Charles University
- Prague 2
- Czech Republic
| | - Alzbeta Lengalova
- Department of Biochemistry
- Faculty of Science
- Charles University
- Prague 2
- Czech Republic
| | - Václav Martínek
- Department of Biochemistry
- Faculty of Science
- Charles University
- Prague 2
- Czech Republic
| | - Markéta Martínková
- Department of Biochemistry
- Faculty of Science
- Charles University
- Prague 2
- Czech Republic
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28
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Koch T, Dahl C. A novel bacterial sulfur oxidation pathway provides a new link between the cycles of organic and inorganic sulfur compounds. ISME JOURNAL 2018; 12:2479-2491. [PMID: 29930335 DOI: 10.1038/s41396-018-0209-7] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 05/16/2018] [Accepted: 06/01/2018] [Indexed: 12/16/2022]
Abstract
Dimethylsulfide (DMS) plays a globally significant role in carbon and sulfur cycling and impacts Earth's climate because its oxidation products serve as nuclei for cloud formation. While the initial steps of aerobic DMS degradation and the fate of its carbon atoms are reasonably well documented, oxidation of the contained sulfur is largely unexplored. Here, we identified a novel pathway of sulfur compound oxidation in the ubiquitously occurring DMS-degrader Hyphomicrobium denitrificans XT that links the oxidation of the volatile organosulfur compound with that of the inorganic sulfur compound thiosulfate. DMS is first transformed to methanethiol from which sulfide is released and fully oxidized to sulfate. Comparative proteomics indicated thiosulfate as an intermediate of this pathway and pointed at a heterodisulfide reductase (Hdr)-like system acting as a sulfur-oxidizing entity. Indeed, marker exchange mutagenesis of hdr-like genes disrupted the ability of H. denitrificans to metabolize DMS and also prevented formation of sulfate from thiosulfate provided as an additional electron source during chemoorganoheterotrophic growth. Complementation with the hdr-like genes under a constitutive promoter rescued the phenotype on thiosulfate as well as on DMS. The production of sulfate from an organosulfur precursor via the Hdr-like system is previously undocumented and provides a new shunt in the biogeochemical sulfur cycle. Furthermore, our findings fill a long-standing knowledge gap in microbial dissimilatory sulfur metabolism because the Hdr-like pathway is abundant not only in chemoheterotrophs, but also in a wide range of chemo- and photolithoautotrophic sulfur oxidizers acting as key players in global sulfur cycling.
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Affiliation(s)
- Tobias Koch
- Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Meckenheimer Allee 168, 53115, Bonn, Germany
| | - Christiane Dahl
- Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Meckenheimer Allee 168, 53115, Bonn, Germany.
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29
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Pyne P, Alam M, Rameez MJ, Mandal S, Sar A, Mondal N, Debnath U, Mathew B, Misra AK, Mandal AK, Ghosh W. Homologs from sulfur oxidation (Sox) and methanol dehydrogenation (Xox) enzyme systems collaborate to give rise to a novel pathway of chemolithotrophic tetrathionate oxidation. Mol Microbiol 2018; 109:169-191. [DOI: 10.1111/mmi.13972] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/16/2018] [Indexed: 11/29/2022]
Affiliation(s)
- Prosenjit Pyne
- Department of Microbiology; Bose Institute, P-1/12 CIT Scheme VIIM; Kolkata 700054 India
| | - Masrure Alam
- Department of Microbiology; Bose Institute, P-1/12 CIT Scheme VIIM; Kolkata 700054 India
| | - Moidu Jameela Rameez
- Department of Microbiology; Bose Institute, P-1/12 CIT Scheme VIIM; Kolkata 700054 India
| | - Subhrangshu Mandal
- Department of Microbiology; Bose Institute, P-1/12 CIT Scheme VIIM; Kolkata 700054 India
| | - Abhijit Sar
- Department of Microbiology; Bose Institute, P-1/12 CIT Scheme VIIM; Kolkata 700054 India
| | - Nibendu Mondal
- Department of Microbiology; Bose Institute, P-1/12 CIT Scheme VIIM; Kolkata 700054 India
| | - Utsab Debnath
- Division of Molecular Medicine; Bose Institute, P-1/12 CIT Scheme VIIM; Kolkata 700054 India
| | - Boby Mathew
- Clinical Proteomics Unit, Division of Molecular Medicine; St. John's Research Institute St. John's National Academy of Health Sciences, 100ft Road; Koramangala 560034 Bangalore India
| | - Anup Kumar Misra
- Division of Molecular Medicine; Bose Institute, P-1/12 CIT Scheme VIIM; Kolkata 700054 India
| | - Amit Kumar Mandal
- Clinical Proteomics Unit, Division of Molecular Medicine; St. John's Research Institute St. John's National Academy of Health Sciences, 100ft Road; Koramangala 560034 Bangalore India
| | - Wriddhiman Ghosh
- Department of Microbiology; Bose Institute, P-1/12 CIT Scheme VIIM; Kolkata 700054 India
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30
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Giedroc DP. A new player in bacterial sulfide-inducible transcriptional regulation. Mol Microbiol 2017; 105:347-352. [PMID: 28612383 DOI: 10.1111/mmi.13726] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 06/07/2017] [Indexed: 12/28/2022]
Abstract
Although hydrogen sulfide (H2 S) is perhaps best known as a toxic gas, the electron-rich H2 S functions as an energy source and electron donor for chemolithotrophic and photosynthetic bacteria, via sulfide oxidation, and is a universal substrate for cysteine biosynthesis. These distinct harmful and beneficial roles of H2 S suggest the need to 'sense' prevailing concentrations of sulfide and downstream reactive sulfur species (RSS) and regulate the expression of genes mediating sulfide homeostasis. The paper by Li et al. in this issue of Molecular Microbiology adds Cupriavidus FisR to an expanding repertoire of regulatory mechanisms that bacteria have evolved to sense cellular RSS and mitigate their deleterious effects.
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Affiliation(s)
- David P Giedroc
- Department of Chemistry, Indiana University, Bloomington, IN, 47405-7102, USA.,Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, 47405-7102, USA
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31
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Influence of haem environment on the catalytic properties of the tetrathionate reductase TsdA from Campylobacter jejuni. Biosci Rep 2016; 36:BSR20160457. [PMID: 27789780 PMCID: PMC5146829 DOI: 10.1042/bsr20160457] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 10/25/2016] [Accepted: 10/26/2016] [Indexed: 01/21/2023] Open
Abstract
In the present study, we provide a detailed analysis of the catalytic properties of the bifunctional thiosulfate dehydrogenases/tetrathionate reductases (TsdA) of the human food-borne pathogen Campylobacter jejuni. Structural differences in the immediate environment of Haem 2 were shown to influence the reaction directionality. Bifunctional dihaem cytochrome c thiosulfate dehydrogenases/tetrathionate reductases (TsdA) exhibit different catalytic properties depending on the source organism. In the human food-borne intestinal pathogen Campylobacter jejuni, TsdA functions as a tetrathionate reductase enabling respiration with tetrathionate as an alternative electron acceptor. In the present study, evidence is provided that Cys138 and Met255 serve as the sixth ligands of Haem 1 and Haem 2 respectively, in the oxidized CjTsdA wt protein. Replacement of Cys138 resulted in a virtually inactive enzyme, confirming Haem 1 as the active site haem. Significantly, TsdA variants carrying amino acid exchanges in the vicinity of the electron-transferring Haem 2 (Met255, Asn254 and Lys252) exhibited markedly altered catalytic properties of the enzyme, showing these residues play a key role in the physiological function of TsdA. The growth phenotypes and tetrathionate reductase activities of a series of ΔtsdA/*tsdA complementation strains constructed in the original host C. jejuni 81116, showed that in vivo, the TsdA variants exhibited the same catalytic properties as the pure, recombinantly produced enzymes. However, variants that catalysed tetrathionate reduction more effectively than the wild-type enzyme did not allow better growth.
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Kurth JM, Brito JA, Reuter J, Flegler A, Koch T, Franke T, Klein EM, Rowe SF, Butt JN, Denkmann K, Pereira IAC, Archer M, Dahl C. Electron Accepting Units of the Diheme Cytochrome c TsdA, a Bifunctional Thiosulfate Dehydrogenase/Tetrathionate Reductase. J Biol Chem 2016; 291:24804-24818. [PMID: 27694441 DOI: 10.1074/jbc.m116.753863] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 09/22/2016] [Indexed: 11/06/2022] Open
Abstract
The enzymes of the thiosulfate dehydrogenase (TsdA) family are wide-spread diheme c-type cytochromes. Here, redox carriers were studied mediating the flow of electrons arising from thiosulfate oxidation into respiratory or photosynthetic electron chains. In a number of organisms, including Thiomonas intermedia and Sideroxydans lithotrophicus, the tsdA gene is immediately preceded by tsdB encoding for another diheme cytochrome. Spectrophotometric experiments in combination with enzymatic assays in solution showed that TsdB acts as an effective electron acceptor of TsdA in vitro when TsdA and TsdB originate from the same source organism. Although TsdA covers a range from -300 to +150 mV, TsdB is redox active between -100 and +300 mV, thus enabling electron transfer between these hemoproteins. The three-dimensional structure of the TsdB-TsdA fusion protein from the purple sulfur bacterium Marichromatium purpuratum was solved by X-ray crystallography to 2.75 Å resolution providing insights into internal electron transfer. In the oxidized state, this tetraheme cytochrome c contains three hemes with axial His/Met ligation, whereas heme 3 exhibits the His/Cys coordination typical for TsdA active sites. Interestingly, thiosulfate is covalently bound to Cys330 on heme 3. In several bacteria, including Allochromatium vinosum, TsdB is not present, precluding a general and essential role for electron flow. Both AvTsdA and the MpTsdBA fusion react efficiently in vitro with high potential iron-sulfur protein from A. vinosum (Em +350 mV). High potential iron-sulfur protein not only acts as direct electron donor to the reaction center in anoxygenic phototrophs but can also be involved in aerobic respiratory chains.
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Affiliation(s)
- Julia M Kurth
- From the Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, 53115 Bonn, Germany
| | - José A Brito
- the Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB-UNL), 2780-157 Oeiras, Portugal, and
| | - Jula Reuter
- From the Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, 53115 Bonn, Germany
| | - Alexander Flegler
- From the Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, 53115 Bonn, Germany
| | - Tobias Koch
- From the Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, 53115 Bonn, Germany
| | - Thomas Franke
- From the Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, 53115 Bonn, Germany
| | - Eva-Maria Klein
- From the Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, 53115 Bonn, Germany
| | - Sam F Rowe
- the Centre for Molecular and Structural Biochemistry, School of Chemistry and School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Julea N Butt
- the Centre for Molecular and Structural Biochemistry, School of Chemistry and School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Kevin Denkmann
- From the Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, 53115 Bonn, Germany
| | - Inês A C Pereira
- the Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB-UNL), 2780-157 Oeiras, Portugal, and
| | - Margarida Archer
- the Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB-UNL), 2780-157 Oeiras, Portugal, and
| | - Christiane Dahl
- From the Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, 53115 Bonn, Germany,
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Kilmartin JR, Bernhardt PV, Dhouib R, Hanson GR, Riley MJ, Kappler U. Effects of mutations in active site heme ligands on the spectroscopic and catalytic properties of SoxAX cytochromes. J Inorg Biochem 2016; 162:309-318. [PMID: 27112898 DOI: 10.1016/j.jinorgbio.2016.04.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 04/04/2016] [Accepted: 04/12/2016] [Indexed: 10/21/2022]
Abstract
By attaching a sulfur substrate to a conserved cysteine of the SoxYZ carrier protein SoxAX cytochromes initiate the reaction cycle of the Sox (sulfur oxidation) multienzyme complex, which is the major pathway for microbial reoxidation of sulfur compounds in the environment. Despite their important role in this process, the reaction mechanism of the SoxAX cytochromes has not been fully elucidated. Here we report the effects of several active site mutations on the spectroscopic and enzymatic properties of the type II SoxAX protein from Starkeya novella, which in addition to two heme groups also contains a Cu redox centre. All substituted proteins contained these redox centres except for His231Ala which was unable to bind Cu(II). Substitution of the SoxA active site heme cysteine ligand with histidine resulted in increased microheterogeneity around the SoxA heme as determined by CW-EPR, while a SnSoxAXC236A substituted protein revealed a completely new, nitrogenous SoxA heme ligand. The same novel ligand was present in SnSoxAXH231A CW-EPR spectra, the first time that a ligand switch of the SoxA heme involving a nearby amino acid has been demonstrated. Kinetically, SnSoxAXC236A and SnSoxAXC236H showed reduced turnover, and in assays containing SoxYZ these mutants retained only ~25% of the wildtype activity. Together, these data indicate that the Cu redox centre can mediate a low level of activity, and that a possible ligand switch can occur during catalysis. It also appears that the SoxA heme cysteine ligand (and possibly the low redox potential) is important for an efficient reaction with SnSoxYZ/thiosulfate.
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Affiliation(s)
- James R Kilmartin
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Qld 4072, Australia
| | - Paul V Bernhardt
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Qld 4072, Australia
| | - Rabeb Dhouib
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Qld 4072, Australia
| | - Graeme R Hanson
- Centre for Advanced Imaging, The University of Queensland, Brisbane, Qld 4072, Australia
| | - Mark J Riley
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Qld 4072, Australia
| | - Ulrike Kappler
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Qld 4072, Australia.
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Kurth JM, Dahl C, Butt JN. Catalytic Protein Film Electrochemistry Provides a Direct Measure of the Tetrathionate/Thiosulfate Reduction Potential. J Am Chem Soc 2015; 137:13232-5. [DOI: 10.1021/jacs.5b08291] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Julia M. Kurth
- Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Meckenheimer Allee 168, D-53115 Bonn, Germany
| | - Christiane Dahl
- Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Meckenheimer Allee 168, D-53115 Bonn, Germany
| | - Julea N. Butt
- Centre
for Molecular and Structural Biochemistry, School of Chemistry, and
School of Biological Sciences, University of East Anglia, Norwich
Research Park, Norwich NR4 7TJ, United Kingdom
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