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Janczak M, Vilhjálmsdóttir J, Ädelroth P. Proton transfer in cytochrome bd-I from E. coli involves Asp-105 in CydB. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2024; 1865:149489. [PMID: 39009175 DOI: 10.1016/j.bbabio.2024.149489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Accepted: 06/27/2024] [Indexed: 07/17/2024]
Abstract
Cytochrome bds are bacterial terminal oxidases expressed under low oxygen conditions, and they are important for the survival of many pathogens and hence potential drug targets. The largest subunit CydA contains the three redox-active cofactors heme b558, heme b595 and the active site heme d. One suggested proton transfer pathway is found at the interface between the CydA and the other major subunit CydB. Here we have studied the O2 reduction mechanism in E. coli cyt. bd-I using the flow-flash technique and focused on the mechanism, kinetics and pathway for proton transfer. Our results show that the peroxy (P) to ferryl (F) transition, coupled to the oxidation of the low-spin heme b558 is pH dependent, with a maximum rate constant (~104 s-1) that is slowed down at higher pH. We assign this behavior to rate-limitation by internal proton transfer from a titratable residue with pKa ~ 9.7. Proton uptake from solution occurs with the same P➔F rate constant. Site-directed mutagenesis shows significant effects on catalytic turnover in the CydB variants Asp58B➔Asn and Asp105B➔Asn variants consistent with them playing a role in proton transfer. Furthermore, in the Asp105B➔Asn variant, the reactions up to P formation occur essentially as in the wildtype bd-I, but the P➔F transition is specifically inhibited, supporting a direct and specific role for Asp105B in the functional proton transfer pathway in bd-I. We further discuss the possible identity of the high pKa proton donor, and the conservation pattern of the Asp-105B in the cyt. bd superfamily.
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Affiliation(s)
- M Janczak
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - J Vilhjálmsdóttir
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - P Ädelroth
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.
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2
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Murali R, Pace LA, Sanford RA, Ward LM, Lynes MM, Hatzenpichler R, Lingappa UF, Fischer WW, Gennis RB, Hemp J. Diversity and evolution of nitric oxide reduction in bacteria and archaea. Proc Natl Acad Sci U S A 2024; 121:e2316422121. [PMID: 38900790 PMCID: PMC11214002 DOI: 10.1073/pnas.2316422121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 04/24/2024] [Indexed: 06/22/2024] Open
Abstract
Nitrous oxide is a potent greenhouse gas whose production is catalyzed by nitric oxide reductase (NOR) members of the heme-copper oxidoreductase (HCO) enzyme superfamily. We identified several previously uncharacterized HCO families, four of which (eNOR, sNOR, gNOR, and nNOR) appear to perform NO reduction. These families have novel active-site structures and several have conserved proton channels, suggesting that they might be able to couple NO reduction to energy conservation. We isolated and biochemically characterized a member of the eNOR family from the bacterium Rhodothermus marinus and found that it performs NO reduction. These recently identified NORs exhibited broad phylogenetic and environmental distributions, greatly expanding the diversity of microbes in nature capable of NO reduction. Phylogenetic analyses further demonstrated that NORs evolved multiple times independently from oxygen reductases, supporting the view that complete denitrification evolved after aerobic respiration.
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Affiliation(s)
- Ranjani Murali
- Department of Biochemistry, University of Illinois, Urbana-Champaign, Urbana, IL61801
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV89154
| | - Laura A. Pace
- Department of Biochemistry, University of Illinois, Urbana-Champaign, Urbana, IL61801
- meliora.bio, Salt Lake City, UT84103
| | - Robert A. Sanford
- Department of Earth Science and Environmental Change, University of Illinois at Urbana-Champaign, Urbana, IL61801
| | - L. M. Ward
- Department of Geosciences, Smith College, Northampton, MA01063
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA91125
| | - Mackenzie M. Lynes
- Department of Chemistry and Biochemistry, Thermal Biology Institute, Montana State University, Bozeman, MT59717
- Center for Biofilm Enginering, Montana State University, Bozeman, MT59717
| | - Roland Hatzenpichler
- Department of Chemistry and Biochemistry, Thermal Biology Institute, Montana State University, Bozeman, MT59717
- Center for Biofilm Enginering, Montana State University, Bozeman, MT59717
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT59717
| | - Usha F. Lingappa
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA91125
- Department of Plant and Microbial Biology, University of California, Berkeley, CA94720
| | - Woodward W. Fischer
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA91125
| | - Robert B. Gennis
- Department of Biochemistry, University of Illinois, Urbana-Champaign, Urbana, IL61801
| | - James Hemp
- meliora.bio, Salt Lake City, UT84103
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA91125
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3
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Franco A, Chukwubuikem A, Meiners C, Rosenbaum MA. Exploring phenazine electron transfer interaction with elements of the respiratory pathways of Pseudomonas putida and Pseudomonas aeruginosa. Bioelectrochemistry 2024; 157:108636. [PMID: 38181591 DOI: 10.1016/j.bioelechem.2023.108636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 11/20/2023] [Accepted: 12/23/2023] [Indexed: 01/07/2024]
Abstract
Pseudomonas aeruginosa phenazines contribute to survival under microaerobic and anaerobic conditions by extracellular electron discharge to regulate cellular redox balances. This electron discharge is also attractive to be used for bioelectrochemical applications. However, elements of the respiratory pathways that interact with phenazines are not well understood. Five terminal oxidases are involved in the aerobic electron transport chain (ETC) of Pseudomonas putida and P. aeruginosa. The latter bacterium also includes four reductases that allow for denitrification. Here, we explored if phenazine-1-carboxylic acid interacts with those elements to enhance anodic electron discharge and drive bacterial growth in oxygen-limited conditions. Bioelectrochemical evaluations of terminal oxidase-deficient mutants of both Pseudomonas strains and P. aeruginosa with stimulated denitrification pathways indicated no direct beneficial interaction of phenazines with ETC elements for extracellular electron discharge. However, the single usage of the Cbb3-2 oxidase increased phenazine production, electron discharge, and cell growth. Assays with purified periplasmic cytochromes NirM and NirS indicated that pyocyanin acts as their electron donor. We conclude that phenazines play an important role in electron transfer to, between, and from terminal oxidases under oxygen-limiting conditions and their modulation might enhance EET. However, the phenazine-anode interaction cannot replace oxygen respiration to deliver energy for biomass formation.
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Affiliation(s)
- Angel Franco
- Bio Pilot Plant, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute (HKI), Beutenbergstr. 11a, 07745 Jena, Germany
| | - Anthony Chukwubuikem
- Bio Pilot Plant, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute (HKI), Beutenbergstr. 11a, 07745 Jena, Germany; Faculty of Biological Sciences, Friedrich Schiller University (FSU), Fürstengraben 1, 07743 Jena, Germany
| | - Carina Meiners
- Bio Pilot Plant, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute (HKI), Beutenbergstr. 11a, 07745 Jena, Germany; Faculty of Biological Sciences, Friedrich Schiller University (FSU), Fürstengraben 1, 07743 Jena, Germany
| | - Miriam A Rosenbaum
- Bio Pilot Plant, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute (HKI), Beutenbergstr. 11a, 07745 Jena, Germany; Faculty of Biological Sciences, Friedrich Schiller University (FSU), Fürstengraben 1, 07743 Jena, Germany.
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4
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Zhong F, Reik ME, Ragusa MJ, Pletneva EV. The structure of the diheme cytochrome c 4 from Neisseria gonorrhoeae reveals multiple contributors to tuning reduction potentials. J Inorg Biochem 2024; 253:112496. [PMID: 38330683 PMCID: PMC11034767 DOI: 10.1016/j.jinorgbio.2024.112496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 01/18/2024] [Accepted: 01/22/2024] [Indexed: 02/10/2024]
Abstract
Cytochrome c4 (c4) is a diheme protein implicated as an electron donor to cbb3 oxidases in multiple pathogenic bacteria. Despite its prevalence, understanding of how specific structural features of c4 optimize its function is lacking. The human pathogen Neisseria gonorrhoeae (Ng) thrives in low oxygen environments owing to the activity of its cbb3 oxidase. Herein, we report characterization of Ng c4. Spectroelectrochemistry experiments of the wild-type (WT) protein have shown that the two Met/His-ligated hemes differ in potentials by ∼100 mV, and studies of the two His/His-ligated variants provided unambiguous assignment of heme A from the N-terminal domain of the protein as the high-potential heme. The crystal structure of the WT protein at 2.45 Å resolution has revealed that the two hemes differ in their solvent accessibility. In particular, interactions made by residues His57 and Ser59 in Loop1 near the axial ligand Met63 contribute to the tight enclosure of heme A, working together with the surface charge, to raise the reduction potential of the heme iron in this domain. The structure reveals a prominent positively-charged patch, which encompasses surfaces of both domains. In contrast to prior findings with c4 from Pseudomonas stutzeri, the interdomain interface of Ng c4 contributes minimally to the values of the heme iron potentials in the two domains. Analyses of the heme solvent accessibility, interface properties, and surface charges offer insights into the interplay of these structural elements in tuning redox properties of c4 and other multiheme proteins.
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Affiliation(s)
- Fangfang Zhong
- Department of Chemistry, Dartmouth College, Hanover, NH 03755, United States
| | - Morgan E Reik
- Department of Chemistry, Dartmouth College, Hanover, NH 03755, United States
| | - Michael J Ragusa
- Department of Chemistry, Dartmouth College, Hanover, NH 03755, United States
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5
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Smiley MK, Sekaran DC, Forouhar F, Wolin E, Jovanovic M, Price-Whelan A, Dietrich LEP. MpaR-driven expression of an orphan terminal oxidase subunit supports Pseudomonas aeruginosa biofilm respiration and development during cyanogenesis. mBio 2024; 15:e0292623. [PMID: 38112469 PMCID: PMC10790758 DOI: 10.1128/mbio.02926-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 11/10/2023] [Indexed: 12/21/2023] Open
Abstract
IMPORTANCE Cyanide is an inhibitor of heme-copper oxidases, which are required for aerobic respiration in all eukaryotes and many prokaryotes. This fast-acting poison can arise from diverse sources, but mechanisms by which bacteria sense it are poorly understood. We investigated the regulatory response to cyanide in the pathogenic bacterium Pseudomonas aeruginosa, which produces cyanide as a virulence factor. Although P. aeruginosa has the capacity to produce a cyanide-resistant oxidase, it relies primarily on heme-copper oxidases and even makes additional heme-copper oxidase proteins specifically under cyanide-producing conditions. We found that the protein MpaR controls expression of cyanide-inducible genes in P. aeruginosa and elucidated the molecular details of this regulation. MpaR contains a DNA-binding domain and a domain predicted to bind pyridoxal phosphate (vitamin B6), a compound that is known to react spontaneously with cyanide. These observations provide insight into the understudied phenomenon of cyanide-dependent regulation of gene expression in bacteria.
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Affiliation(s)
- Marina K. Smiley
- Department of Biological Sciences, Columbia University, New York, New York, USA
| | - Doran C. Sekaran
- Department of Biological Sciences, Columbia University, New York, New York, USA
| | - Farhad Forouhar
- Herbert Irving Comprehensive Cancer Center, Columbia University, New York, New York, USA
| | - Erica Wolin
- Department of Biological Sciences, Columbia University, New York, New York, USA
| | - Marko Jovanovic
- Department of Biological Sciences, Columbia University, New York, New York, USA
| | - Alexa Price-Whelan
- Department of Biological Sciences, Columbia University, New York, New York, USA
| | - Lars E. P. Dietrich
- Department of Biological Sciences, Columbia University, New York, New York, USA
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6
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Aronson HS, Clark CE, LaRowe DE, Amend JP, Polerecky L, Macalady JL. Sulfur disproportionating microbial communities in a dynamic, microoxic-sulfidic karst system. GEOBIOLOGY 2023; 21:791-803. [PMID: 37721188 DOI: 10.1111/gbi.12574] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 07/24/2023] [Accepted: 08/29/2023] [Indexed: 09/19/2023]
Abstract
Biogeochemical sulfur cycling in sulfidic karst systems is largely driven by abiotic and biological sulfide oxidation, but the fate of elemental sulfur (S0 ) that accumulates in these systems is not well understood. The Frasassi Cave system (Italy) is intersected by a sulfidic aquifer that mixes with small quantities of oxygen-rich meteoric water, creating Proterozoic-like conditions and supporting a prolific ecosystem driven by sulfur-based chemolithoautotrophy. To better understand the cycling of S0 in this environment, we examined the geochemistry and microbiology of sediments underlying widespread sulfide-oxidizing mats dominated by Beggiatoa. Sediment populations were dominated by uncultivated relatives of sulfur cycling chemolithoautotrophs related to Sulfurovum, Halothiobacillus, Thiofaba, Thiovirga, Thiobacillus, and Desulfocapsa, as well as diverse uncultivated anaerobic heterotrophs affiliated with Bacteroidota, Anaerolineaceae, Lentimicrobiaceae, and Prolixibacteraceae. Desulfocapsa and Sulfurovum populations accounted for 12%-26% of sediment 16S rRNA amplicon sequences and were closely related to isolates which carry out autotrophic S0 disproportionation in pure culture. Gibbs energy (∆Gr ) calculations revealed that S0 disproportionation under in situ conditions is energy yielding. Microsensor profiles through the mat-sediment interface showed that Beggiatoa mats consume dissolved sulfide and oxygen, but a net increase in acidity was only observed in the sediments below. Together, these findings suggest that disproportionation is an important sink for S0 generated by microbial sulfide oxidation in this oxygen-limited system and may contribute to the weathering of carbonate rocks and sediments in sulfur-rich environments.
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Affiliation(s)
- Heidi S Aronson
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| | - Christian E Clark
- Department of Geosciences, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Douglas E LaRowe
- Department of Earth Sciences, University of Southern California, Los Angeles, California, USA
| | - Jan P Amend
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
- Department of Earth Sciences, University of Southern California, Los Angeles, California, USA
| | - Lubos Polerecky
- Department of Earth Sciences, Utrecht University, Utrecht, The Netherlands
| | - Jennifer L Macalady
- Department of Geosciences, Pennsylvania State University, University Park, Pennsylvania, USA
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7
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Li Y, He X, Lin Y, Li YX, Kamenev GM, Li J, Qiu JW, Sun J. Reduced chemosymbiont genome in the methane seep thyasirid and the cooperated metabolisms in the holobiont under anaerobic sediment. Mol Ecol Resour 2023; 23:1853-1867. [PMID: 37486074 DOI: 10.1111/1755-0998.13846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 06/16/2023] [Accepted: 07/11/2023] [Indexed: 07/25/2023]
Abstract
Previous studies have deciphered the genomic basis of host-symbiont metabolic complementarity in vestimentiferans, bathymodioline mussels, vesicomyid clams and Alviniconcha snails, yet little is known about the chemosynthetic symbiosis in Thyasiridae-a family of Bivalvia regarded as an excellent model in chemosymbiosis research due to their wide distribution in both deep-sea and shallow-water habitats. We report the first circular thyasirid symbiont genome, named Candidatus Ruthturnera sp. Tsphm01, with a size of 1.53 Mb, 1521 coding genes and 100% completeness. Compared to its free-living relatives, Ca. Ruthturnera sp. Tsphm01 genome is reduced, lacking components for chemotaxis, citric acid cycle and de novo biosynthesis of small molecules (e.g. amino acids and cofactors), indicating it is likely an obligate intracellular symbiont. Nevertheless, the symbiont retains complete genomic components of sulphur oxidation and assimilation of inorganic carbon, and these systems were highly and actively expressed. Moreover, the symbiont appears well-adapted to anoxic environment, including capable of anaerobic respiration (i.e. reductions of DMSO and nitrate) and possession of a low oxygen-adapted type of cytochrome c oxidase. Analysis of the host transcriptome revealed its metabolic complementarity to the incomplete metabolic pathways of the symbiont and the acquisition of nutrients from the symbiont via phagocytosis and exosome. By providing the first complete genome of reduced size in a thyasirid symbiont, this study enhances our understanding of the diversity of symbiosis that has enabled bivalves to thrive in chemosynthetic habitats. The resources will be widely used in phylogenetic, geographic and evolutionary studies of chemosynthetic bacteria and bivalves.
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Affiliation(s)
- Yunlong Li
- Institute of Evolution & Marine Biodiversity, Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, China
- Laoshan Laboratory, Qingdao, China
| | - Xing He
- Institute of Evolution & Marine Biodiversity, Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, China
- Laoshan Laboratory, Qingdao, China
| | - Yuxuan Lin
- Department of Ocean Science, Hong Kong University of Science and Technology, Hong Kong, China
| | - Yi-Xuan Li
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Gennady M Kamenev
- A.V. Zhirmunsky National Scientific Center of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, Vladivostok, Russian Federation
| | - Jiying Li
- Department of Ocean Science, Hong Kong University of Science and Technology, Hong Kong, China
| | - Jian-Wen Qiu
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Jin Sun
- Institute of Evolution & Marine Biodiversity, Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, China
- Laoshan Laboratory, Qingdao, China
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8
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Khalfaoui-Hassani B, Blaby-Haas CE, Verissimo A, Daldal F. The Escherichia coli MFS-type transporter genes yhjE, ydiM, and yfcJ are required to produce an active bo3 quinol oxidase. PLoS One 2023; 18:e0293015. [PMID: 37862358 PMCID: PMC10588857 DOI: 10.1371/journal.pone.0293015] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 10/04/2023] [Indexed: 10/22/2023] Open
Abstract
Heme-copper oxygen reductases are membrane-bound oligomeric complexes that are integral to prokaryotic and eukaryotic aerobic respiratory chains. Biogenesis of these enzymes is complex and requires coordinated assembly of the subunits and their cofactors. Some of the components are involved in the acquisition and integration of different heme and copper (Cu) cofactors into these terminal oxygen reductases. As such, MFS-type transporters of the CalT family (e.g., CcoA) are required for Cu import and heme-CuB center biogenesis of the cbb3-type cytochrome c oxidases (cbb3-Cox). However, functionally homologous Cu transporters for similar heme-Cu containing bo3-type quinol oxidases (bo3-Qox) are unknown. Despite the occurrence of multiple MFS-type transporters, orthologs of CcoA are absent in bacteria like Escherichia coli that contain bo3-Qox. In this work, we identified a subset of uncharacterized MFS transporters, based on the presence of putative metal-binding residues, as likely candidates for the missing Cu transporter. Using a genetic approach, we tested whether these transporters are involved in the biogenesis of E. coli bo3-Qox. When respiratory growth is dependent on bo3-Qox, because of deletion of the bd-type Qox enzymes, three candidate genes, yhjE, ydiM, and yfcJ, were found to be critical for E. coli growth. Radioactive metal uptake assays showed that ΔydiM has a slower 64Cu uptake, whereas ΔyhjE accumulates reduced 55Fe in the cell, while no similar uptake defect is associated with ΔycfJ. Phylogenomic analyses suggest plausible roles for the YhjE, YdiM, and YfcJ transporters, and overall findings illustrate the diverse roles that the MFS-type transporters play in cellular metal homeostasis and production of active heme-Cu oxygen reductases.
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Affiliation(s)
- Bahia Khalfaoui-Hassani
- Université de Pau et des Pays de l’Adour, E2S UPPA, IPREM, UMR CNRS, Pau, France
- Department of Biology, University of Pennsylvania, Philadelphia, PA, United States of America
| | - Crysten E. Blaby-Haas
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, United States of America
- Lawrence Berkeley National Laboratory, The Molecular Foundry, Berkeley, CA, United States of America
| | - Andreia Verissimo
- Department of Biology, University of Pennsylvania, Philadelphia, PA, United States of America
- bioMT-Institute for Biomolecular Targeting, Geisel School of Medicine at Dartmouth, Hanover, NH, United States of America
| | - Fevzi Daldal
- Department of Biology, University of Pennsylvania, Philadelphia, PA, United States of America
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9
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Di Trani JM, Gheorghita AA, Turner M, Brzezinski P, Ädelroth P, Vahidi S, Howell PL, Rubinstein JL. Structure of the bc1- cbb3 respiratory supercomplex from Pseudomonas aeruginosa. Proc Natl Acad Sci U S A 2023; 120:e2307093120. [PMID: 37751552 PMCID: PMC10556555 DOI: 10.1073/pnas.2307093120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 08/14/2023] [Indexed: 09/28/2023] Open
Abstract
Energy conversion by electron transport chains occurs through the sequential transfer of electrons between protein complexes and intermediate electron carriers, creating the proton motive force that enables ATP synthesis and membrane transport. These protein complexes can also form higher order assemblies known as respiratory supercomplexes (SCs). The electron transport chain of the opportunistic pathogen Pseudomonas aeruginosa is closely linked with its ability to invade host tissue, tolerate harsh conditions, and resist antibiotics but is poorly characterized. Here, we determine the structure of a P. aeruginosa SC that forms between the quinol:cytochrome c oxidoreductase (cytochrome bc1) and one of the organism's terminal oxidases, cytochrome cbb3, which is found only in some bacteria. Remarkably, the SC structure also includes two intermediate electron carriers: a diheme cytochrome c4 and a single heme cytochrome c5. Together, these proteins allow electron transfer from ubiquinol in cytochrome bc1 to oxygen in cytochrome cbb3. We also present evidence that different isoforms of cytochrome cbb3 can participate in formation of this SC without changing the overall SC architecture. Incorporating these different subunit isoforms into the SC would allow the bacterium to adapt to different environmental conditions. Bioinformatic analysis focusing on structural motifs in the SC suggests that cytochrome bc1-cbb3 SCs also exist in other bacterial pathogens.
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Affiliation(s)
- Justin M. Di Trani
- Molecular Medicine program, The Hospital for Sick Children, Toronto, ONM5G 0A4, Canada
| | - Andreea A. Gheorghita
- Molecular Medicine program, The Hospital for Sick Children, Toronto, ONM5G 0A4, Canada
- Department of Biochemistry, The University of Toronto, Toronto, ONM5S 1A8, Canada
| | - Madison Turner
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ONN1G 2W1, Canada
| | - Peter Brzezinski
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, StockholmSE-106 91, Sweden
| | - Pia Ädelroth
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, StockholmSE-106 91, Sweden
| | - Siavash Vahidi
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ONN1G 2W1, Canada
| | - P. Lynne Howell
- Molecular Medicine program, The Hospital for Sick Children, Toronto, ONM5G 0A4, Canada
- Department of Biochemistry, The University of Toronto, Toronto, ONM5S 1A8, Canada
| | - John L. Rubinstein
- Molecular Medicine program, The Hospital for Sick Children, Toronto, ONM5G 0A4, Canada
- Department of Biochemistry, The University of Toronto, Toronto, ONM5S 1A8, Canada
- Department of Medical Biophysics, The University of Toronto, Toronto, ONM5G 1L7, Canada
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10
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Siletsky SA. Investigation of the Mechanism of Membrane Potential Generation by Heme-Copper Respiratory Oxidases in a Real Time Mode. BIOCHEMISTRY. BIOKHIMIIA 2023; 88:1513-1527. [PMID: 38105021 DOI: 10.1134/s0006297923100085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 08/15/2023] [Accepted: 08/15/2023] [Indexed: 12/19/2023]
Abstract
Heme-copper respiratory oxidases are highly efficient molecular machines. These membrane enzymes catalyze the final step of cellular respiration in eukaryotes and many prokaryotes: the transfer of electrons from cytochromes or quinols to molecular oxygen and oxygen reduction to water. The free energy released in this redox reaction is converted by heme-copper respiratory oxidases into the transmembrane gradient of the electrochemical potential of hydrogen ions H+). Heme-copper respiratory oxidases have a unique mechanism for generating H+, namely, a redox-coupled proton pump. A combination of direct electrometric method for measuring the kinetics of membrane potential generation with the methods of prestationary kinetics and site-directed mutagenesis in the studies of heme-copper oxidases allows to obtain a unique information on the translocation of protons inside the proteins in real time. The review summarizes the data of studies employing time-resolved electrometry to decipher the mechanisms of functioning of these important bioenergetic enzymes.
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Affiliation(s)
- Sergei A Siletsky
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
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11
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Meier-Credo J, Heiniger B, Schori C, Rupprecht F, Michel H, Ahrens CH, Langer JD. Detection of Known and Novel Small Proteins in Pseudomonas stutzeri Using a Combination of Bottom-Up and Digest-Free Proteomics and Proteogenomics. Anal Chem 2023; 95:11892-11900. [PMID: 37535005 PMCID: PMC10433244 DOI: 10.1021/acs.analchem.3c00676] [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: 02/14/2023] [Accepted: 07/24/2023] [Indexed: 08/04/2023]
Abstract
Small proteins of around 50 aa in length have been largely overlooked in genetic and biochemical assays due to the inherent challenges with detecting and characterizing them. Recent discoveries of their critical roles in many biological processes have led to an increased recognition of the importance of small proteins for basic research and as potential new drug targets. One example is CcoM, a 36 aa subunit of the cbb3-type oxidase that plays an essential role in adaptation to oxygen-limited conditions in Pseudomonas stutzeri (P. stutzeri), a model for the clinically relevant, opportunistic pathogen Pseudomonas aeruginosa. However, as no comprehensive data were available in P. stutzeri, we devised an integrated, generic approach to study small proteins more systematically. Using the first complete genome as basis, we conducted bottom-up proteomics analyses and established a digest-free, direct-sequencing proteomics approach to study cells grown under aerobic and oxygen-limiting conditions. Finally, we also applied a proteogenomics pipeline to identify missed protein-coding genes. Overall, we identified 2921 known and 29 novel proteins, many of which were differentially regulated. Among 176 small proteins 16 were novel. Direct sequencing, featuring a specialized precursor acquisition scheme, exhibited advantages in the detection of small proteins with higher (up to 100%) sequence coverage and more spectral counts, including sequences with high proline content. Three novel small proteins, uniquely identified by direct sequencing and not conserved beyond P. stutzeri, were predicted to form an operon with a conserved protein and may represent de novo genes. These data demonstrate the power of this combined approach to study small proteins in P. stutzeri and show its potential for other prokaryotes.
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Affiliation(s)
- Jakob Meier-Credo
- Proteomics, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Benjamin Heiniger
- Molecular
Ecology, Agroscope & SIB Swiss Institute
of Bioinformatics, 8046 Zürich, Switzerland
| | - Christian Schori
- Molecular
Ecology, Agroscope & SIB Swiss Institute
of Bioinformatics, 8046 Zürich, Switzerland
| | - Fiona Rupprecht
- Proteomics, Max Planck Institute for Brain
Research, 60438 Frankfurt
am Main, Germany
| | - Hartmut Michel
- Department
of Molecular Membrane Biology, Max Planck
Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Christian H. Ahrens
- Molecular
Ecology, Agroscope & SIB Swiss Institute
of Bioinformatics, 8046 Zürich, Switzerland
| | - Julian D. Langer
- Proteomics, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
- Proteomics, Max Planck Institute for Brain
Research, 60438 Frankfurt
am Main, Germany
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12
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Smiley MK, Sekaran DC, Price-Whelan A, Dietrich LE. Cyanide-dependent control of terminal oxidase hybridization by Pseudomonas aeruginosa MpaR. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.31.543164. [PMID: 37398129 PMCID: PMC10312525 DOI: 10.1101/2023.05.31.543164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Pseudomonas aeruginosa is a common, biofilm-forming pathogen that exhibits complex pathways of redox metabolism. It produces four different types of terminal oxidases for aerobic respiration, and for one of these-the cbb3-type terminal oxidases-it has the capacity to produce at least 16 isoforms encoded by partially redundant operons. It also produces small-molecule virulence factors that interact with the respiratory chain, including the poison cyanide. Previous studies had indicated a role for cyanide in activating expression of an "orphan" terminal oxidase subunit gene called ccoN4 and that the product contributes to P. aeruginosa cyanide resistance, fitness in biofilms, and virulence-but the mechanisms underlying this process had not been elucidated. Here, we show that the regulatory protein MpaR, which is predicted to be a pyridoxal phosphate-binding transcription factor and is encoded just upstream of ccoN4, controls ccoN4 expression in response to endogenous cyanide. Paradoxically, we find that cyanide production is required to support CcoN4's contribution to respiration in biofilms. We identify a palindromic motif required for cyanide- and MpaR-dependent expression of ccoN4 and co-expressed, adjacent loci. We also characterize the regulatory logic of this region of the chromosome. Finally, we identify residues in the putative cofactor-binding pocket of MpaR that are required for ccoN4 expression. Together, our findings illustrate a novel scenario in which the respiratory toxin cyanide acts as a signal to control gene expression in a bacterium that produces the compound endogenously.
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Affiliation(s)
- Marina K. Smiley
- Department of Biological Sciences, Columbia University, New York, NY 10025
| | - Doran C. Sekaran
- Department of Biological Sciences, Columbia University, New York, NY 10025
| | - Alexa Price-Whelan
- Department of Biological Sciences, Columbia University, New York, NY 10025
| | - Lars E.P. Dietrich
- Department of Biological Sciences, Columbia University, New York, NY 10025
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13
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Flynn AJ, Antonyuk SV, Eady RR, Muench SP, Hasnain SS. A 2.2 Å cryoEM structure of a quinol-dependent NO Reductase shows close similarity to respiratory oxidases. Nat Commun 2023; 14:3416. [PMID: 37296134 PMCID: PMC10256718 DOI: 10.1038/s41467-023-39140-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 05/31/2023] [Indexed: 06/12/2023] Open
Abstract
Quinol-dependent nitric oxide reductases (qNORs) are considered members of the respiratory heme-copper oxidase superfamily, are unique to bacteria, and are commonly found in pathogenic bacteria where they play a role in combating the host immune response. qNORs are also essential enzymes in the denitrification pathway, catalysing the reduction of nitric oxide to nitrous oxide. Here, we determine a 2.2 Å cryoEM structure of qNOR from Alcaligenes xylosoxidans, an opportunistic pathogen and a denitrifying bacterium of importance in the nitrogen cycle. This high-resolution structure provides insight into electron, substrate, and proton pathways, and provides evidence that the quinol binding site not only contains the conserved His and Asp residues but also possesses a critical Arg (Arg720) observed in cytochrome bo3, a respiratory quinol oxidase.
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Affiliation(s)
- Alex J Flynn
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
- Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Svetlana V Antonyuk
- Molecular Biophysics Group, Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool, L69 7ZB, England
| | - Robert R Eady
- Molecular Biophysics Group, Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool, L69 7ZB, England
| | - Stephen P Muench
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK.
- Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK.
| | - S Samar Hasnain
- Molecular Biophysics Group, Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool, L69 7ZB, England.
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14
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Wang F, Li L, Li X, Hu X, Zhang B. Pulsed electric field promotes the growth metabolism of aerobic denitrifying bacteria Pseudomonas putida W207-14 by improving cell membrane permeability. ENVIRONMENTAL TECHNOLOGY 2023; 44:2327-2340. [PMID: 35001840 DOI: 10.1080/09593330.2022.2027028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 12/11/2021] [Indexed: 06/04/2023]
Abstract
The purpose of this study was to explore the stimulation mechanism of low pulsed electric field (PEF) strength treatment to promote the growth metabolism of aerobic denitrifying bacteria Pseudomonas putida W207-14. The results indicated that compared with the control group, the strain W207-14 treated with PEF entered the logarithmic growth phase 5 h earlier, the growth time to reached the maximum cell optical density at 600 nm (OD600) of 1.935 ± 0.04 was only 24 h, which shortened by half. With the reduction of growth time, the metabolic rate of the strain increased significantly, in which the removal efficiency of COD, NO3--N and TN was 97.67 ± 1.12%, 90.34 ± 0.73% and 90.13 ± 0.10% in 24 h, respectively. The maximum nitrate removal rate increased from 3.49 mg/L/h to 7.53 mg/L/h. A large number of cells with simultaneous cell membrane damage and high physiological activity were observed by flow cytometry (FCM) in combination with fluorescence staining analysis, which confirmed the reversible electroporation on the cell membrane of strain W207-14 treated with PEF. Transcriptomic analysis indicated that PEF activated the highly significant differential expression of membrane porin (opdB, opdC, and oprB) and cytochrome oxidoreductase related genes (ccoP, ccoN, cioA and cioB) on the cell membrane, which promoted the transport of nutrients through the cell membrane and electron transfer during aerobic respiration and provided an explanation for the possible mechanism of PEF promoting the growth metabolism of strain W207-14 at the micro level. These results lay a foundation for the practical application of PEF enhanced aerobic denitrification technology.
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Affiliation(s)
- Fan Wang
- School of Resource & Civil Engineering, Northeastern University, Shenyang, People's Republic of China
| | - Liang Li
- School of Resource & Civil Engineering, Northeastern University, Shenyang, People's Republic of China
| | - Xuejie Li
- School of Resource & Civil Engineering, Northeastern University, Shenyang, People's Republic of China
| | - Xiaomin Hu
- School of Resource & Civil Engineering, Northeastern University, Shenyang, People's Republic of China
| | - Bo Zhang
- School of Resource & Civil Engineering, Northeastern University, Shenyang, People's Republic of China
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15
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Wu D, Mehdipour AR, Finke F, Goojani HG, Groh RR, Grund TN, Reichhart TMB, Zimmermann R, Welsch S, Bald D, Shepherd M, Hummer G, Safarian S. Dissecting the conformational complexity and mechanism of a bacterial heme transporter. Nat Chem Biol 2023:10.1038/s41589-023-01314-5. [PMID: 37095238 PMCID: PMC10374445 DOI: 10.1038/s41589-023-01314-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 03/14/2023] [Indexed: 04/26/2023]
Abstract
Iron-bound cyclic tetrapyrroles (hemes) are redox-active cofactors in bioenergetic enzymes. However, the mechanisms of heme transport and insertion into respiratory chain complexes remain unclear. Here, we used cellular, biochemical, structural and computational methods to characterize the structure and function of the heterodimeric bacterial ABC transporter CydDC. We provide multi-level evidence that CydDC is a heme transporter required for functional maturation of cytochrome bd, a pharmaceutically relevant drug target. Our systematic single-particle cryogenic-electron microscopy approach combined with atomistic molecular dynamics simulations provides detailed insight into the conformational landscape of CydDC during substrate binding and occlusion. Our simulations reveal that heme binds laterally from the membrane space to the transmembrane region of CydDC, enabled by a highly asymmetrical inward-facing CydDC conformation. During the binding process, heme propionates interact with positively charged residues on the surface and later in the substrate-binding pocket of the transporter, causing the heme orientation to rotate 180°.
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Affiliation(s)
- Di Wu
- Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, Frankfurt/Main, Germany
| | - Ahmad R Mehdipour
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Frankfurt/Main, Germany
- Center for Molecular Modeling (CMM), Ghent University, Zwijnaarde, Belgium
| | - Franziska Finke
- Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, Frankfurt/Main, Germany
| | - Hojjat G Goojani
- Amsterdam Institute for Life and Environment (A-LIFE), AIMMS, Faculty of Science, Vrije University of Amsterdam, Amsterdam, the Netherlands
| | - Roan R Groh
- Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, Frankfurt/Main, Germany
| | - Tamara N Grund
- Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, Frankfurt/Main, Germany
| | - Thomas M B Reichhart
- Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, Frankfurt/Main, Germany
| | - Rita Zimmermann
- Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, Frankfurt/Main, Germany
| | - Sonja Welsch
- Central Electron Microscopy Facility, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Dirk Bald
- Amsterdam Institute for Life and Environment (A-LIFE), AIMMS, Faculty of Science, Vrije University of Amsterdam, Amsterdam, the Netherlands
| | - Mark Shepherd
- School of Biosciences, RAPID Group, University of Kent, Canterbury, UK
| | - Gerhard Hummer
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Frankfurt/Main, Germany
- Institute of Biophysics, Goethe University Frankfurt, Frankfurt/Main, Germany
| | - Schara Safarian
- Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, Frankfurt/Main, Germany.
- Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Frankfurt/Main, Germany.
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16
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Muramoto K, Shinzawa-Itoh K. Calcium-bound structure of bovine cytochrome c oxidase. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148956. [PMID: 36708913 DOI: 10.1016/j.bbabio.2023.148956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 01/11/2023] [Accepted: 01/20/2023] [Indexed: 01/26/2023]
Abstract
The crystal structure of bovine cytochrome c oxidase (CcO) shows a sodium ion (Na+) bound to the surface of subunit I. Changes in the absorption spectrum of heme a caused by calcium ions (Ca2+) are detected as small red shifts, and inhibition of enzymatic activity under low turnover conditions is observed by addition of Ca2+ in a competitive manner with Na+. In this study, we determined the crystal structure of Ca2+-bound bovine CcO in the oxidized and reduced states at 1.7 Å resolution. Although Ca2+ and Na+ bound to the same site of oxidized and reduced CcO, they led to different coordination geometries. Replacement of Na+ with Ca2+ caused a small structural change in the loop segments near the heme a propionate and formyl groups, resulting in spectral changes in heme a. Redox-coupled structural changes observed in the Ca2+-bound form were the same as those previously observed in the Na+-bound form, suggesting that binding of Ca2+ does not severely affect enzymatic function, which depends on these structural changes. The relation between the Ca2+ binding and the inhibitory effect during slow turnover, as well as the possible role of bound Ca2+ are discussed.
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Affiliation(s)
- Kazumasa Muramoto
- Graduate School of Science, University of Hyogo, 3-2-1 Kouto, Kamigori, Ako, Hyogo 678-1297, Japan.
| | - Kyoko Shinzawa-Itoh
- Graduate School of Science, University of Hyogo, 3-2-1 Kouto, Kamigori, Ako, Hyogo 678-1297, Japan.
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17
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Structures of the intermediates in the catalytic cycle of mitochondrial cytochrome c oxidase. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148933. [PMID: 36403794 DOI: 10.1016/j.bbabio.2022.148933] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 10/30/2022] [Accepted: 11/07/2022] [Indexed: 11/18/2022]
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18
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Azarkina NV, Borisov VB, Oleynikov IP, Sudakov RV, Vygodina TV. Interaction of Terminal Oxidases with Amphipathic Molecules. Int J Mol Sci 2023; 24:ijms24076428. [PMID: 37047401 PMCID: PMC10095113 DOI: 10.3390/ijms24076428] [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: 03/13/2023] [Revised: 03/26/2023] [Accepted: 03/27/2023] [Indexed: 04/14/2023] Open
Abstract
The review focuses on recent advances regarding the effects of natural and artificial amphipathic compounds on terminal oxidases. Terminal oxidases are fascinating biomolecular devices which couple the oxidation of respiratory substrates with generation of a proton motive force used by the cell for ATP production and other needs. The role of endogenous lipids in the enzyme structure and function is highlighted. The main regularities of the interaction between the most popular detergents and terminal oxidases of various types are described. A hypothesis about the physiological regulation of mitochondrial-type enzymes by lipid-soluble ligands is considered.
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Affiliation(s)
- Natalia V Azarkina
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory 1, Bld. 40, 119992 Moscow, Russia
| | - Vitaliy B Borisov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory 1, Bld. 40, 119992 Moscow, Russia
| | - Ilya P Oleynikov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory 1, Bld. 40, 119992 Moscow, Russia
| | - Roman V Sudakov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory 1, Bld. 40, 119992 Moscow, Russia
| | - Tatiana V Vygodina
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory 1, Bld. 40, 119992 Moscow, Russia
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19
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Dharamshi JE, Köstlbacher S, Schön ME, Collingro A, Ettema TJG, Horn M. Gene gain facilitated endosymbiotic evolution of Chlamydiae. Nat Microbiol 2023; 8:40-54. [PMID: 36604515 PMCID: PMC9816063 DOI: 10.1038/s41564-022-01284-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 11/07/2022] [Indexed: 01/07/2023]
Abstract
Chlamydiae is a bacterial phylum composed of obligate animal and protist endosymbionts. However, other members of the Planctomycetes-Verrucomicrobia-Chlamydiae superphylum are primarily free living. How Chlamydiae transitioned to an endosymbiotic lifestyle is still largely unresolved. Here we reconstructed Planctomycetes-Verrucomicrobia-Chlamydiae species relationships and modelled superphylum genome evolution. Gene content reconstruction from 11,996 gene families suggests a motile and facultatively anaerobic last common Chlamydiae ancestor that had already gained characteristic endosymbiont genes. Counter to expectations for genome streamlining in strict endosymbionts, we detected substantial gene gain within Chlamydiae. We found that divergence in energy metabolism and aerobiosis observed in extant lineages emerged later during chlamydial evolution. In particular, metabolic and aerobic genes characteristic of the more metabolically versatile protist-infecting chlamydiae were gained, such as respiratory chain complexes. Our results show that metabolic complexity can increase during endosymbiont evolution, adding an additional perspective for understanding symbiont evolutionary trajectories across the tree of life.
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Affiliation(s)
- Jennah E Dharamshi
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Stephan Köstlbacher
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Vienna, Austria
- University of Vienna, Doctoral School in Microbiology and Environmental Science, Vienna, Austria
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, The Netherlands
| | - Max E Schön
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Astrid Collingro
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Vienna, Austria
| | - Thijs J G Ettema
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden.
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, The Netherlands.
| | - Matthias Horn
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Vienna, Austria.
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20
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Murali R, Hemp J, Gennis RB. Evolution of quinol oxidation within the heme‑copper oxidoreductase superfamily. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2022; 1863:148907. [PMID: 35944661 DOI: 10.1016/j.bbabio.2022.148907] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Revised: 07/09/2022] [Accepted: 08/02/2022] [Indexed: 06/15/2023]
Abstract
The heme‑copper oxidoreductase (HCO) superfamily is a large superfamily of terminal respiratory enzymes that are widely distributed across the three domains of life. The superfamily includes biochemically diverse oxygen reductases and nitric oxide reductases that are pivotal in the pathways of aerobic respiration and denitrification. The adaptation of HCOs to use quinol as the electron donor instead of cytochrome c has significant implication for the respiratory flexibility and energetic efficiency of the respiratory chains that include them. In this work, we explore the adaptation of this scaffold to two different electron donors, cytochromes c and quinols, with extensive sequence analysis of these enzymes from publicly available datasets. Our work shows that quinol oxidation evolved independently within the HCO superfamily at least seven times. Enzymes from only two of these independently evolved clades have been biochemically well-characterized. Combining structural modeling with sequence analysis, we identify putative quinol binding sites in each of the novel quinol oxidases. Our analysis of experimental and modeling data suggests that the quinol binding site appears to have evolved at the same structural position within the scaffold more than once.
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Affiliation(s)
- Ranjani Murali
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91106, USA.
| | - James Hemp
- Metrodora Institute, West Valley City, UT, USA 84119.
| | - Robert B Gennis
- Department of Biochemistry, University of Illinois, Urbana-Champaign, Urbana, IL 61801, USA.
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21
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Electric fields control water-gated proton transfer in cytochrome c oxidase. Proc Natl Acad Sci U S A 2022; 119:e2207761119. [PMID: 36095184 PMCID: PMC9499568 DOI: 10.1073/pnas.2207761119] [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] [Indexed: 11/18/2022] Open
Abstract
Aerobic life is powered by membrane-bound enzymes that catalyze the transfer of electrons to oxygen and protons across a biological membrane. Cytochrome c oxidase (CcO) functions as a terminal electron acceptor in mitochondrial and bacterial respiratory chains, driving cellular respiration and transducing the free energy from O2 reduction into proton pumping. Here we show that CcO creates orientated electric fields around a nonpolar cavity next to the active site, establishing a molecular switch that directs the protons along distinct pathways. By combining large-scale quantum chemical density functional theory (DFT) calculations with hybrid quantum mechanics/molecular mechanics (QM/MM) simulations and atomistic molecular dynamics (MD) explorations, we find that reduction of the electron donor, heme a, leads to dissociation of an arginine (Arg438)-heme a3 D-propionate ion-pair. This ion-pair dissociation creates a strong electric field of up to 1 V Å-1 along a water-mediated proton array leading to a transient proton loading site (PLS) near the active site. Protonation of the PLS triggers the reduction of the active site, which in turn aligns the electric field vectors along a second, "chemical," proton pathway. We find a linear energy relationship of the proton transfer barrier with the electric field strength that explains the effectivity of the gating process. Our mechanism shows distinct similarities to principles also found in other energy-converting enzymes, suggesting that orientated electric fields generally control enzyme catalysis.
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22
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Nayek A, Ahmed ME, Samanta S, Dinda S, Patra S, Dey SG, Dey A. Bioinorganic Chemistry on Electrodes: Methods to Functional Modeling. J Am Chem Soc 2022; 144:8402-8429. [PMID: 35503922 DOI: 10.1021/jacs.2c01842] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
One of the major goals of bioinorganic chemistry has been to mimic the function of elegant metalloenzymes. Such functional modeling has been difficult to attain in solution, in particular, for reactions that require multiple protons and multiple electrons (nH+/ne-). Using a combination of heterogeneous electrochemistry, electrode and molecule design one may control both electron transfer (ET) and proton transfer (PT) of these nH+/ne- reactions. Such control can allow functional modeling of hydrogenases (H+ + e- → 1/2 H2), cytochrome c oxidase (O2 + 4 e- + 4 H+ → 2 H2O), monooxygenases (RR'CH2 + O2 + 2 e- + 2 H+ → RR'CHOH + H2O) and dioxygenases (S + O2 → SO2; S = organic substrate) in aqueous medium and at room temperatures. In addition, these heterogeneous constructs allow probing unnatural bioinspired reactions and estimation of the inner- and outer-sphere reorganization energy of small molecules and proteins.
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Affiliation(s)
- Abhijit Nayek
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A Raja SC Mullick Road, Kolkata, WB India 700032
| | - Md Estak Ahmed
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A Raja SC Mullick Road, Kolkata, WB India 700032
| | - Soumya Samanta
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A Raja SC Mullick Road, Kolkata, WB India 700032
| | - Souvik Dinda
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A Raja SC Mullick Road, Kolkata, WB India 700032
| | - Suman Patra
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A Raja SC Mullick Road, Kolkata, WB India 700032
| | - Somdatta Ghosh Dey
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A Raja SC Mullick Road, Kolkata, WB India 700032
| | - Abhishek Dey
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A Raja SC Mullick Road, Kolkata, WB India 700032
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23
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Diversity of Cytochrome c Oxidase Assembly Proteins in Bacteria. Microorganisms 2022; 10:microorganisms10050926. [PMID: 35630371 PMCID: PMC9145763 DOI: 10.3390/microorganisms10050926] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 04/26/2022] [Accepted: 04/27/2022] [Indexed: 12/10/2022] Open
Abstract
Cytochrome c oxidase in animals, plants and many aerobic bacteria functions as the terminal enzyme of the respiratory chain where it reduces molecular oxygen to form water in a reaction coupled to energy conservation. The three-subunit core of the enzyme is conserved, whereas several proteins identified to function in the biosynthesis of the common family A1 cytochrome c oxidase show diversity in bacteria. Using the model organisms Bacillus subtilis, Corynebacterium glutamicum, Paracoccus denitrificans, and Rhodobacter sphaeroides, the present review focuses on proteins for assembly of the heme a, heme a3, CuB, and CuA metal centers. The known biosynthesis proteins are, in most cases, discovered through the analysis of mutants. All proteins directly involved in cytochrome c oxidase assembly have likely not been identified in any organism. Limitations in the use of mutants to identify and functionally analyze biosynthesis proteins are discussed in the review. Comparative biochemistry helps to determine the role of assembly factors. This information can, for example, explain the cause of some human mitochondrion-based diseases and be used to find targets for new antimicrobial drugs. It also provides information regarding the evolution of aerobic bacteria.
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Williams TJ, Allen MA, Panwar P, Cavicchioli R. Into the darkness: The ecologies of novel 'microbial dark matter' phyla in an Antarctic lake. Environ Microbiol 2022; 24:2576-2603. [PMID: 35466505 PMCID: PMC9324843 DOI: 10.1111/1462-2920.16026] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 04/18/2022] [Accepted: 04/20/2022] [Indexed: 11/29/2022]
Abstract
Uncultivated microbial clades ("microbial dark matter") are inferred to play important, but uncharacterized roles in nutrient cycling. Using Antarctic lake (Ace Lake, Vestfold Hills) metagenomes, 12 metagenome-assembled genomes (MAGs; 88-100% complete) were generated for four "dark matter" phyla: six MAGs from Candidatus Auribacterota (= Aureabacteria, SURF-CP-2), inferred to be hydrogen- and sulfide-producing fermentative heterotrophs, with individual MAGs encoding bacterial microcompartments (BMCs), gas vesicles, and type IV pili; one MAG (100% complete) from Candidatus Hinthialibacterota (= OLB16), inferred to be a facultative anaerobe capable of dissimilatory nitrate reduction to ammonia, specialized for mineralization of complex organic matter (e.g., sulfated polysaccharides), and encoding BMCs, flagella, and Tad pili; three MAGs from Candidatus Electryoneota (= AABM5-125-24), previously reported to include facultative anaerobes capable of dissimilatory sulfate reduction, and here inferred to perform sulfite oxidation, reverse tricarboxylic acid cycle for autotrophy, and possess numerous proteolytic enzymes; two MAGs from Candidatus Lernaellota (= FEN-1099), inferred to be capable of formate oxidation, amino acid fermentation, and possess numerous enzymes for protein and polysaccharide degradation. The presence of 16S rRNA gene sequences in public metagenome datasets (88-100% identity) suggests these "dark matter" phyla contribute to sulfur cycling, degradation of complex organic matter, ammonification and/or chemolithoautrophic CO2 fixation in diverse global environments. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Timothy J Williams
- School of Biotechnology and Biomolecular Sciences UNSW Sydney, Sydney, New South Wales, 2052, Australia
| | - Michelle A Allen
- School of Biotechnology and Biomolecular Sciences UNSW Sydney, Sydney, New South Wales, 2052, Australia
| | - Pratibha Panwar
- School of Biotechnology and Biomolecular Sciences UNSW Sydney, Sydney, New South Wales, 2052, Australia
| | - Ricardo Cavicchioli
- School of Biotechnology and Biomolecular Sciences UNSW Sydney, Sydney, New South Wales, 2052, Australia
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25
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Chen J, Xie P, Huang Y, Gao H. Complex Interplay of Heme-Copper Oxidases with Nitrite and Nitric Oxide. Int J Mol Sci 2022; 23:979. [PMID: 35055165 PMCID: PMC8780969 DOI: 10.3390/ijms23020979] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/13/2022] [Accepted: 01/15/2022] [Indexed: 12/19/2022] Open
Abstract
Nitrite and nitric oxide (NO), two active and critical nitrogen oxides linking nitrate to dinitrogen gas in the broad nitrogen biogeochemical cycle, are capable of interacting with redox-sensitive proteins. The interactions of both with heme-copper oxidases (HCOs) serve as the foundation not only for the enzymatic interconversion of nitrogen oxides but also for the inhibitory activity. From extensive studies, we now know that NO interacts with HCOs in a rapid and reversible manner, either competing with oxygen or not. During interconversion, a partially reduced heme/copper center reduces the nitrite ion, producing NO with the heme serving as the reductant and the cupric ion providing a Lewis acid interaction with nitrite. The interaction may lead to the formation of either a relatively stable nitrosyl-derivative of the enzyme reduced or a more labile nitrite-derivative of the enzyme oxidized through two different pathways, resulting in enzyme inhibition. Although nitrite and NO show similar biochemical properties, a growing body of evidence suggests that they are largely treated as distinct molecules by bacterial cells. NO seemingly interacts with all hemoproteins indiscriminately, whereas nitrite shows high specificity to HCOs. Moreover, as biologically active molecules and signal molecules, nitrite and NO directly affect the activity of different enzymes and are perceived by completely different sensing systems, respectively, through which they are linked to different biological processes. Further attempts to reconcile this apparent contradiction could open up possible avenues for the application of these nitrogen oxides in a variety of fields, the pharmaceutical industry in particular.
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Affiliation(s)
| | | | | | - Haichun Gao
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China; (J.C.); (P.X.); (Y.H.)
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Yu Q, Sun W, Gao H. Thiosulfate oxidation in sulfur-reducing Shewanella oneidensis and its unexpected influences on the cytochrome c content. Environ Microbiol 2021; 23:7056-7072. [PMID: 34664382 DOI: 10.1111/1462-2920.15807] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 09/04/2021] [Accepted: 10/07/2021] [Indexed: 12/13/2022]
Abstract
Thiosulfate, an important form of sulfur compounds, can serve as both electron donor and acceptor in various microorganisms. In Shewanella oneidensis, a bacterium renowned for respiratory versatility, thiosulfate reduction has long been recognized but whether it can catalyse thiosulfate oxidation remains elusive. In this study, we discovered that S. oneidensis is capable of thiosulfate oxidation, a process specifically catalysed by two periplasmic cytochrome c (cyt c) proteins, TsdA and TsdB, which act as the catalytic subunit and the electron transfer subunit respectively. In the presence of oxygen, oxidation of thiosulfate has priority over reduction. Intriguingly, thiosulfate oxidation negatively regulates the cyt c content in S. oneidensis cells, largely by reducing intracellular levels of cAMP, which as the cofactor modulates activity of global regulator Crp required for transcription of many cyt c genes. This unexpected finding provides an additional dimension to interplays between the respiration regulator and the respiratory pathways in S. oneidensis. Moreover, the data presented here identified S. oneidensis as the first bacterium known to date owning both functional thiosulfate reductase and dehydrogenase, and importantly, genomics analyses suggested that the number of bacterial species possessing this feature is rather limited.
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Affiliation(s)
- Qingzi Yu
- Institute of Microbiology and College of Life Sciences, Zhejiang University, Zhejiang, Hangzhou, 310058, China
| | - Weining Sun
- Institute of Microbiology and College of Life Sciences, Zhejiang University, Zhejiang, Hangzhou, 310058, China
| | - Haichun Gao
- Institute of Microbiology and College of Life Sciences, Zhejiang University, Zhejiang, Hangzhou, 310058, China
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27
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Siletsky SA, Borisov VB. Proton Pumping and Non-Pumping Terminal Respiratory Oxidases: Active Sites Intermediates of These Molecular Machines and Their Derivatives. Int J Mol Sci 2021; 22:10852. [PMID: 34639193 PMCID: PMC8509429 DOI: 10.3390/ijms221910852] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/04/2021] [Accepted: 10/05/2021] [Indexed: 11/16/2022] Open
Abstract
Terminal respiratory oxidases are highly efficient molecular machines. These most important bioenergetic membrane enzymes transform the energy of chemical bonds released during the transfer of electrons along the respiratory chains of eukaryotes and prokaryotes from cytochromes or quinols to molecular oxygen into a transmembrane proton gradient. They participate in regulatory cascades and physiological anti-stress reactions in multicellular organisms. They also allow microorganisms to adapt to low-oxygen conditions, survive in chemically aggressive environments and acquire antibiotic resistance. To date, three-dimensional structures with atomic resolution of members of all major groups of terminal respiratory oxidases, heme-copper oxidases, and bd-type cytochromes, have been obtained. These groups of enzymes have different origins and a wide range of functional significance in cells. At the same time, all of them are united by a catalytic reaction of four-electron reduction in oxygen into water which proceeds without the formation and release of potentially dangerous ROS from active sites. The review analyzes recent structural and functional studies of oxygen reduction intermediates in the active sites of terminal respiratory oxidases, the features of catalytic cycles, and the properties of the active sites of these enzymes.
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Affiliation(s)
- Sergey A. Siletsky
- Department of Bioenergetics, Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory, Moscow 119991, Russia
| | - Vitaliy B. Borisov
- Department of Molecular Energetics of Microorganisms, Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory, Moscow 119991, Russia;
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28
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Bertling K, Banerjee A, Saffarini D. Aerobic Respiration and Its Regulation in the Metal Reducer Shewanella oneidensis. Front Microbiol 2021; 12:723835. [PMID: 34566926 PMCID: PMC8458880 DOI: 10.3389/fmicb.2021.723835] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 07/26/2021] [Indexed: 11/23/2022] Open
Abstract
Shewanella oneidensis MR-1 is a facultative anaerobe known for its ability to reduce metal oxides. Anaerobic respiration, especially metal reduction, has been the subject of extensive research. In contrast, S. oneidensis aerobic respiration has received less attention. S. oneidensis expresses cbb3- and aa3-type cytochrome c oxidases and a bd-type quinol oxidase. The aa3-type oxidase, which in other bacteria is the major oxygen reductase under oxygen replete conditions, does not appear to contribute to aerobic respiration and growth in S. oneidensis. Our results indicated that although the aa3-type oxidase does not play a role in aerobic growth on lactate, the preferred carbon source for S. oneidensis, it is involved in growth on pyruvate or acetate. These results highlight the importance of testing multiple carbon and energy sources when attempting to identify enzyme activities and mutant phenotypes. Several regulatory proteins contribute to the regulation of aerobic growth in S. oneidensis including CRP and ArcA. The 3',5'-cAMP phosphodiesterase (CpdA) appears to play a more significant role in aerobic growth than either CRP or ArcA, yet the deficiency does not appear to be the result of reduced oxidase genes expression. Interestingly, the ∆cpdA mutant was more deficient in aerobic respiration with several carbon sources tested compared to ∆crp, which was moderately deficient only in the presence of lactate. To identify the reason for ∆cpdA aerobic growth deficiency, we isolated a suppressor mutant with transposon insertion in SO_3550. Inactivation of this gene, which encodes an anti-sigma factor, restored aerobic growth in the cpdA mutant to wild-type levels. Inactivation of SO_3550 in wild-type cells, however, did not affect aerobic growth. The S. oneidensis genome encodes two additional CRP-like proteins that we designated CrpB and CrpC. Mutants that lack crpB and crpC were deficient in aerobic growth, but this deficiency was not due to the loss of oxidase gene expression.
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Affiliation(s)
- Kristen Bertling
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI, United States
| | - Areen Banerjee
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI, United States
| | - Daad Saffarini
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI, United States
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29
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Rivett ED, Heo L, Feig M, Hegg EL. Biosynthesis and trafficking of heme o and heme a: new structural insights and their implications for reaction mechanisms and prenylated heme transfer. Crit Rev Biochem Mol Biol 2021; 56:640-668. [PMID: 34428995 DOI: 10.1080/10409238.2021.1957668] [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] [Indexed: 10/20/2022]
Abstract
Aerobic respiration is a key energy-producing pathway in many prokaryotes and virtually all eukaryotes. The final step of aerobic respiration is most commonly catalyzed by heme-copper oxidases embedded in the cytoplasmic or mitochondrial membrane. The majority of these terminal oxidases contain a prenylated heme (typically heme a or occasionally heme o) in the active site. In addition, many heme-copper oxidases, including mitochondrial cytochrome c oxidases, possess a second heme a cofactor. Despite the critical role of heme a in the electron transport chain, the details of the mechanism by which heme b, the prototypical cellular heme, is converted to heme o and then to heme a remain poorly understood. Recent structural investigations, however, have helped clarify some elements of heme a biosynthesis. In this review, we discuss the insight gained from these advances. In particular, we present a new structural model of heme o synthase (HOS) based on distance restraints from inferred coevolutionary relationships and refined by molecular dynamics simulations that are in good agreement with the experimentally determined structures of HOS homologs. We also analyze the two structures of heme a synthase (HAS) that have recently been solved by other groups. For both HOS and HAS, we discuss the proposed catalytic mechanisms and highlight how new insights into the heme-binding site locations shed light on previously obtained biochemical data. Finally, we explore the implications of the new structural data in the broader context of heme trafficking in the heme a biosynthetic pathway and heme-copper oxidase assembly.
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Affiliation(s)
- Elise D Rivett
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
| | - Lim Heo
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
| | - Michael Feig
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
| | - Eric L Hegg
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
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30
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Microaerobic Lifestyle at Nanomolar O 2 Concentrations Mediated by Low-Affinity Terminal Oxidases in Abundant Soil Bacteria. mSystems 2021; 6:e0025021. [PMID: 34227829 PMCID: PMC8407424 DOI: 10.1128/msystems.00250-21] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
High-affinity terminal oxidases (TOs) are believed to permit microbial respiration at low oxygen (O2) levels. Genes encoding such oxidases are widespread, and their existence in microbial genomes is taken as an indicator for microaerobic respiration. We combined respiratory kinetics determined via highly sensitive optical trace O2 sensors, genomics, and transcriptomics to test the hypothesis that high-affinity TOs are a prerequisite to respire micro- and nanooxic concentrations of O2 in environmentally relevant model soil organisms: acidobacteria. Members of the Acidobacteria harbor branched respiratory chains terminating in low-affinity (caa3-type cytochrome c oxidases) as well as high-affinity (cbb3-type cytochrome c oxidases and/or bd-type quinol oxidases) TOs, potentially enabling them to cope with varying O2 concentrations. The measured apparent Km (Km(app)) values for O2 of selected strains ranged from 37 to 288 nmol O2 liter−1, comparable to values previously assigned to low-affinity TOs. Surprisingly, we could not detect the expression of the conventional high-affinity TO (cbb3 type) at micro- and nanomolar O2 concentrations but detected the expression of low-affinity TOs. To the best of our knowledge, this is the first observation of microaerobic respiration imparted by low-affinity TOs at O2 concentrations as low as 1 nM. This challenges the standing hypothesis that a microaerobic lifestyle is exclusively imparted by the presence of high-affinity TOs. As low-affinity TOs are more efficient at generating ATP than high-affinity TOs, their utilization could provide a great benefit, even at low-nanomolar O2 levels. Our findings highlight energy conservation strategies that could promote the success of Acidobacteria in soil but might also be important for as-yet-unrevealed microorganisms. IMPORTANCE Low-oxygen habitats are widely distributed on Earth, ranging from the human intestine to soils. Microorganisms are assumed to have the capacity to respire low O2 concentrations via high-affinity terminal oxidases. By utilizing strains of a ubiquitous and abundant group of soil bacteria, the Acidobacteria, and combining respiration kinetics, genomics, and transcriptomics, we provide evidence that these microorganisms use the energetically more efficient low-affinity terminal oxidases to respire low-nanomolar O2 concentrations. This questions the standing hypothesis that the ability to respire traces of O2 stems solely from the activity of high-affinity terminal oxidases. We propose that this energetically efficient strategy extends into other, so-far-unrevealed microbial clades. Our findings also demonstrate that physiological predictions regarding the utilization of different O2 concentrations based solely on the presence or absence of terminal oxidases in bacterial genomes can be misleading.
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31
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Garg N, Taylor AJ, Pastorelli F, Flannery SE, Jackson PJ, Johnson MP, Kelly DJ. Genes Linking Copper Trafficking and Homeostasis to the Biogenesis and Activity of the cbb 3-Type Cytochrome c Oxidase in the Enteric Pathogen Campylobacter jejuni. Front Microbiol 2021; 12:683260. [PMID: 34248902 PMCID: PMC8267372 DOI: 10.3389/fmicb.2021.683260] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Accepted: 05/26/2021] [Indexed: 11/13/2022] Open
Abstract
Bacterial C-type haem-copper oxidases in the cbb 3 family are widespread in microaerophiles, which exploit their high oxygen-binding affinity for growth in microoxic niches. In microaerophilic pathogens, C-type oxidases can be essential for infection, yet little is known about their biogenesis compared to model bacteria. Here, we have identified genes involved in cbb 3-oxidase (Cco) assembly and activity in the Gram-negative pathogen Campylobacter jejuni, the commonest cause of human food-borne bacterial gastroenteritis. Several genes of unknown function downstream of the oxidase structural genes ccoNOQP were shown to be essential (cj1483c and cj1486c) or important (cj1484c and cj1485c) for Cco activity; Cj1483 is a CcoH homologue, but Cj1484 (designated CcoZ) has structural similarity to MSMEG_4692, involved in Qcr-oxidase supercomplex formation in Mycobacterium smegmatis. Blue-native polyacrylamide gel electrophoresis of detergent solubilised membranes revealed three major bands, one of which contained CcoZ along with Qcr and oxidase subunits. Deletion of putative copper trafficking genes ccoI (cj1155c) and ccoS (cj1154c) abolished Cco activity, which was partially restored by addition of copper during growth, while inactivation of cj0369c encoding a CcoG homologue led to a partial reduction in Cco activity. Deletion of an operon encoding PCu A C (Cj0909) and Sco (Cj0911) periplasmic copper chaperone homologues reduced Cco activity, which was partially restored in the cj0911 mutant by exogenous copper. Phenotypic analyses of gene deletions in the cj1161c-1166c cluster, encoding several genes involved in intracellular metal homeostasis, showed that inactivation of copA (cj1161c), or copZ (cj1162c) led to both elevated intracellular Cu and reduced Cco activity, effects exacerbated at high external Cu. Our work has therefore identified (i) additional Cco subunits, (ii) a previously uncharacterized set of genes linking copper trafficking and Cco activity, and (iii) connections with Cu homeostasis in this important pathogen.
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Affiliation(s)
- Nitanshu Garg
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, United Kingdom
| | - Aidan J Taylor
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, United Kingdom
| | - Federica Pastorelli
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, United Kingdom
| | - Sarah E Flannery
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, United Kingdom
| | - Phillip J Jackson
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, United Kingdom
| | - Matthew P Johnson
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, United Kingdom
| | - David J Kelly
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, United Kingdom
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32
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Borisov VB, Siletsky SA, Nastasi MR, Forte E. ROS Defense Systems and Terminal Oxidases in Bacteria. Antioxidants (Basel) 2021; 10:antiox10060839. [PMID: 34073980 PMCID: PMC8225038 DOI: 10.3390/antiox10060839] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 05/19/2021] [Accepted: 05/21/2021] [Indexed: 02/07/2023] Open
Abstract
Reactive oxygen species (ROS) comprise the superoxide anion (O2•−), hydrogen peroxide (H2O2), hydroxyl radical (•OH), and singlet oxygen (1O2). ROS can damage a variety of macromolecules, including DNA, RNA, proteins, and lipids, and compromise cell viability. To prevent or reduce ROS-induced oxidative stress, bacteria utilize different ROS defense mechanisms, of which ROS scavenging enzymes, such as superoxide dismutases, catalases, and peroxidases, are the best characterized. Recently, evidence has been accumulating that some of the terminal oxidases in bacterial respiratory chains may also play a protective role against ROS. The present review covers this role of terminal oxidases in light of recent findings.
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Affiliation(s)
- Vitaliy B. Borisov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory, 119991 Moscow, Russia;
- Correspondence: (V.B.B.); (E.F.)
| | - Sergey A. Siletsky
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory, 119991 Moscow, Russia;
| | - Martina R. Nastasi
- Department of Biochemical Sciences, Sapienza University of Rome, Piazzale Aldo Moro, 5, 00185 Rome, Italy;
| | - Elena Forte
- Department of Biochemical Sciences, Sapienza University of Rome, Piazzale Aldo Moro, 5, 00185 Rome, Italy;
- Correspondence: (V.B.B.); (E.F.)
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33
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Blomberg MRA. Activation of O 2 and NO in heme-copper oxidases - mechanistic insights from computational modelling. Chem Soc Rev 2021; 49:7301-7330. [PMID: 33006348 DOI: 10.1039/d0cs00877j] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Heme-copper oxidases are transmembrane enzymes involved in aerobic and anaerobic respiration. The largest subgroup contains the cytochrome c oxidases (CcO), which reduce molecular oxygen to water. A significant part of the free energy released in this exergonic process is conserved as an electrochemical gradient across the membrane, via two processes, electrogenic chemistry and proton pumping. A deviant subgroup is the cytochrome c dependent NO reductases (cNOR), which reduce nitric oxide to nitrous oxide and water. This is also an exergonic reaction, but in this case none of the released free energy is conserved. Computational studies applying hybrid density functional theory to cluster models of the bimetallic active sites in the heme-copper oxidases are reviewed. To obtain a reliable description of the reaction mechanisms, energy profiles of the entire catalytic cycles, including the reduction steps have to be constructed. This requires a careful combination of computational results with certain experimental data. Computational studies have elucidated mechanistic details of the chemical parts of the reactions, involving cleavage and formation of covalent bonds, which have not been obtainable from pure experimental investigations. Important insights regarding the mechanisms of energy conservation have also been gained. The computational studies show that the reduction potentials of the active site cofactors in the CcOs are large enough to afford electrogenic chemistry and proton pumping, i.e. efficient energy conservation. These results solve a conflict between different types of experimental data. A mechanism for the proton pumping, involving a specific and crucial role for the active site tyrosine, conserved in all CcOs, is suggested. For the cNORs, the calculations show that the low reduction potentials of the active site cofactors are optimized for fast elimination of the toxic NO molecules. At the same time, the low reduction potentials lead to endergonic reduction steps with high barriers. To prevent even higher barriers, which would lead to a too slow reaction, when the electrochemical gradient across the membrane is present, the chemistry must occur in a non-electrogenic manner. This explains why there is no energy conservation in cNOR.
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Affiliation(s)
- Margareta R A Blomberg
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91, Stockholm, Sweden.
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Abstract
Bacteria power their energy metabolism using membrane-bound respiratory enzymes that capture chemical energy and transduce it by pumping protons or Na+ ions across their cell membranes. Recent breakthroughs in molecular bioenergetics have elucidated the architecture and function of many bacterial respiratory enzymes, although key mechanistic principles remain debated. In this Review, we present an overview of the structure, function and bioenergetic principles of modular bacterial respiratory chains and discuss their differences from the eukaryotic counterparts. We also discuss bacterial supercomplexes, which provide central energy transduction systems in several bacteria, including important pathogens, and which could open up possible avenues for treatment of disease.
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Fedotovskaya O, Albertsson I, Nordlund G, Hong S, Gennis RB, Brzezinski P, Ädelroth P. Identification of a cytochrome bc 1-aa 3 supercomplex in Rhodobacter sphaeroides. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2021; 1862:148433. [PMID: 33932366 DOI: 10.1016/j.bbabio.2021.148433] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 04/19/2021] [Accepted: 04/20/2021] [Indexed: 10/21/2022]
Abstract
Respiration is carried out by a series of membrane-bound complexes in the inner mitochondrial membrane or in the cytoplasmic membrane of bacteria. Increasing evidence shows that these complexes organize into larger supercomplexes. In this work, we identified a supercomplex composed of cytochrome (cyt.) bc1 and aa3-type cyt. c oxidase in Rhodobacter sphaeroides. We purified the supercomplex using a His-tag on either of these complexes. The results from activity assays, native and denaturing PAGE, size exclusion chromatography, electron microscopy, optical absorption spectroscopy and kinetic studies on the purified samples support the formation and coupled quinol oxidation:O2 reduction activity of the cyt. bc1-aa3 supercomplex. The potential role of the membrane-anchored cyt. cy as a component in supercomplexes was also investigated.
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Affiliation(s)
- Olga Fedotovskaya
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Ingrid Albertsson
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Gustav Nordlund
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Sangjin Hong
- Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, IL 61801, USA
| | - Robert B Gennis
- Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, IL 61801, USA
| | - Peter Brzezinski
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Pia Ädelroth
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden.
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36
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Muntyan MS, Morozov DA, Leonova YF, Ovchinnikova TV. Identification of Na+-Pumping Cytochrome Oxidase in the Membranes of Extremely Alkaliphilic Thioalkalivibrio Bacteria. BIOCHEMISTRY (MOSCOW) 2021; 85:1631-1639. [PMID: 33705300 DOI: 10.1134/s0006297920120147] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
For the first time, the functioning of the oxygen reductase Na+-pump (Na+-pumping cytochrome c oxidase of the cbb3-type) was demonstrated by examining the respiratory chain of the extremely alkaliphilic bacterium Thioalkalivibrio versutus [Muntyan, M. S., et al. (2015) Cytochrome cbb3 of Thioalkalivibrio is a Na+-pumping cytochrome oxidase, Proc. Natl. Acad. Sci. USA, 112, 7695-7700], a product of the ccoNOQP operon. In this study, we detected and identified this enzyme using rabbit polyclonal antibody against the predicted C-terminal amino acid sequence of its catalytic subunit. We found that this cbb3-type oxidase is synthesized in bacterial cells, where it is located in the membranes. The 48-kDa oxidase subunit (CcoN) is catalytic, while subunits CcoO and CcoP with molecular masses of 29 and 34 kDa, respectively, are cytochromes c. The theoretical pI values of the CcoN, CcoO, and CcoP subunits were determined. It was shown that parts of the CcoO and CcoP subunits exposed to the aqueous phase on the cytoplasmic membrane P-side are enriched with negatively charged amino acid residues, in contrast to the parts of the integral subunit CcoN adjacent to the aqueous phase. Thus, the Na+-pumping cytochrome c oxidase of T. versutus, both in function and in structure, demonstrates adaptation to extremely alkaline conditions.
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Affiliation(s)
- M S Muntyan
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
| | - D A Morozov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Y F Leonova
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia
| | - T V Ovchinnikova
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia
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37
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Zhang Y, Li Z, Liu Y, Cen X, Liu D, Chen Z. Systems metabolic engineering of Vibrio natriegens for the production of 1,3-propanediol. Metab Eng 2021; 65:52-65. [PMID: 33722653 DOI: 10.1016/j.ymben.2021.03.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 02/28/2021] [Accepted: 03/06/2021] [Indexed: 11/18/2022]
Abstract
The economic viability of current bio-production systems is often limited by its low productivity due to slow cell growth and low substrate uptake rate. The fastest-growing bacterium Vibrio natriegens is a highly promising next-generation workhorse of the biotechnology industry which can utilize various industrially relevant carbon sources with high substrate uptake rates. Here, we demonstrate the first systematic engineering example of V. natriegens for the heterologous production of 1,3-propanediol (1,3-PDO) from glycerol. Systems metabolic engineering strategies have been applied in this study to develop a superior 1,3-PDO producer, including: (1) heterologous pathway construction and optimization; (2) engineering cellular transcriptional regulators and global transcriptomic analysis; (3) enhancing intracellular reducing power by cofactor engineering; (4) reducing the accumulation of toxic intermediate by pathway engineering; (5) systematic engineering of glycerol oxidation pathway to eliminate byproduct formation. A final engineered strain can efficiently produce 1,3-PDO with a titer of 56.2 g/L, a yield of 0.61 mol/mol, and an average productivity of 2.36 g/L/h. The strategies described in this study would be useful for engineering V. natriegens as a potential chassis for the production of other useful chemicals and biofuels.
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Affiliation(s)
- Ye Zhang
- Key Laboratory of Industrial Biocatalysis (Ministry of Education), Department of Chemical Engineering, Tsinghua University, Beijing, 100084, China
| | - Zihua Li
- Key Laboratory of Industrial Biocatalysis (Ministry of Education), Department of Chemical Engineering, Tsinghua University, Beijing, 100084, China
| | - Yu Liu
- Key Laboratory of Industrial Biocatalysis (Ministry of Education), Department of Chemical Engineering, Tsinghua University, Beijing, 100084, China
| | - Xuecong Cen
- Key Laboratory of Industrial Biocatalysis (Ministry of Education), Department of Chemical Engineering, Tsinghua University, Beijing, 100084, China
| | - Dehua Liu
- Key Laboratory of Industrial Biocatalysis (Ministry of Education), Department of Chemical Engineering, Tsinghua University, Beijing, 100084, China; Tsinghua Innovation Center in Dongguan, Dongguan, 523808, China; Center for Synthetic and Systems Biology, Tsinghua University, Beijing, 100084, China
| | - Zhen Chen
- Key Laboratory of Industrial Biocatalysis (Ministry of Education), Department of Chemical Engineering, Tsinghua University, Beijing, 100084, China; Tsinghua Innovation Center in Dongguan, Dongguan, 523808, China; Center for Synthetic and Systems Biology, Tsinghua University, Beijing, 100084, China.
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38
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Reed CJ, Lam QN, Mirts EN, Lu Y. Molecular understanding of heteronuclear active sites in heme-copper oxidases, nitric oxide reductases, and sulfite reductases through biomimetic modelling. Chem Soc Rev 2021; 50:2486-2539. [PMID: 33475096 PMCID: PMC7920998 DOI: 10.1039/d0cs01297a] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Heme-copper oxidases (HCO), nitric oxide reductases (NOR), and sulfite reductases (SiR) catalyze the multi-electron and multi-proton reductions of O2, NO, and SO32-, respectively. Each of these reactions is important to drive cellular energy production through respiratory metabolism and HCO, NOR, and SiR evolved to contain heteronuclear active sites containing heme/copper, heme/nonheme iron, and heme-[4Fe-4S] centers, respectively. The complexity of the structures and reactions of these native enzymes, along with their large sizes and/or membrane associations, make it challenging to fully understand the crucial structural features responsible for the catalytic properties of these active sites. In this review, we summarize progress that has been made to better understand these heteronuclear metalloenzymes at the molecular level though study of the native enzymes along with insights gained from biomimetic models comprising either small molecules or proteins. Further understanding the reaction selectivity of these enzymes is discussed through comparisons of their similar heteronuclear active sites, and we offer outlook for further investigations.
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Affiliation(s)
- Christopher J Reed
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urban, IL 61801, USA.
| | - Quan N Lam
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urban, IL 61801, USA
| | - Evan N Mirts
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Yi Lu
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urban, IL 61801, USA. and Department of Biochemistry, University of Illinois at Urbana-Champaign, Urban, IL 61801, USA and Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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39
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The road to the structure of the mitochondrial respiratory chain supercomplex. Biochem Soc Trans 2021; 48:621-629. [PMID: 32311046 PMCID: PMC7200630 DOI: 10.1042/bst20190930] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 03/30/2020] [Accepted: 03/31/2020] [Indexed: 01/04/2023]
Abstract
The four complexes of the mitochondrial respiratory chain are critical for ATP production in most eukaryotic cells. Structural characterisation of these complexes has been critical for understanding the mechanisms underpinning their function. The three proton-pumping complexes, Complexes I, III and IV associate to form stable supercomplexes or respirasomes, the most abundant form containing 80 subunits in mammals. Multiple functions have been proposed for the supercomplexes, including enhancing the diffusion of electron carriers, providing stability for the complexes and protection against reactive oxygen species. Although high-resolution structures for Complexes III and IV were determined by X-ray crystallography in the 1990s, the size of Complex I and the supercomplexes necessitated advances in sample preparation and the development of cryo-electron microscopy techniques. We now enjoy structures for these beautiful complexes isolated from multiple organisms and in multiple states and together they provide important insights into respiratory chain function and the role of the supercomplex. While we as non-structural biologists use these structures for interpreting our own functional data, we need to remind ourselves that they stand on the shoulders of a large body of previous structural studies, many of which are still appropriate for use in understanding our results. In this mini-review, we discuss the history of respiratory chain structural biology studies leading to the structures of the mammalian supercomplexes and beyond.
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Cryo-EM structures of engineered active bc 1-cbb 3 type CIII 2CIV super-complexes and electronic communication between the complexes. Nat Commun 2021; 12:929. [PMID: 33568648 PMCID: PMC7876108 DOI: 10.1038/s41467-021-21051-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 01/06/2021] [Indexed: 01/30/2023] Open
Abstract
Respiratory electron transport complexes are organized as individual entities or combined as large supercomplexes (SC). Gram-negative bacteria deploy a mitochondrial-like cytochrome (cyt) bc1 (Complex III, CIII2), and may have specific cbb3-type cyt c oxidases (Complex IV, CIV) instead of the canonical aa3-type CIV. Electron transfer between these complexes is mediated by soluble (c2) and membrane-anchored (cy) cyts. Here, we report the structure of an engineered bc1-cbb3 type SC (CIII2CIV, 5.2 Å resolution) and three conformers of native CIII2 (3.3 Å resolution). The SC is active in vivo and in vitro, contains all catalytic subunits and cofactors, and two extra transmembrane helices attributed to cyt cy and the assembly factor CcoH. The cyt cy is integral to SC, its cyt domain is mobile and it conveys electrons to CIV differently than cyt c2. The successful production of a native-like functional SC and determination of its structure illustrate the characteristics of membrane-confined and membrane-external respiratory electron transport pathways in Gram-negative bacteria.
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Calisto F, Sousa FM, Sena FV, Refojo PN, Pereira MM. Mechanisms of Energy Transduction by Charge Translocating Membrane Proteins. Chem Rev 2021; 121:1804-1844. [PMID: 33398986 DOI: 10.1021/acs.chemrev.0c00830] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Life relies on the constant exchange of different forms of energy, i.e., on energy transduction. Therefore, organisms have evolved in a way to be able to harvest the energy made available by external sources (such as light or chemical compounds) and convert these into biological useable energy forms, such as the transmembrane difference of electrochemical potential (Δμ̃). Membrane proteins contribute to the establishment of Δμ̃ by coupling exergonic catalytic reactions to the translocation of charges (electrons/ions) across the membrane. Irrespectively of the energy source and consequent type of reaction, all charge-translocating proteins follow two molecular coupling mechanisms: direct- or indirect-coupling, depending on whether the translocated charge is involved in the driving reaction. In this review, we explore these two coupling mechanisms by thoroughly examining the different types of charge-translocating membrane proteins. For each protein, we analyze the respective reaction thermodynamics, electron transfer/catalytic processes, charge-translocating pathways, and ion/substrate stoichiometries.
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Affiliation(s)
- Filipa Calisto
- Instituto de Tecnologia Química e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157, Oeiras, Portugal.,BioISI-Biosystems & Integrative Sciences Institute, University of Lisboa, Faculty of Sciences, Campo Grande, 1749-016 Lisboa, Portugal
| | - Filipe M Sousa
- Instituto de Tecnologia Química e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157, Oeiras, Portugal.,BioISI-Biosystems & Integrative Sciences Institute, University of Lisboa, Faculty of Sciences, Campo Grande, 1749-016 Lisboa, Portugal
| | - Filipa V Sena
- Instituto de Tecnologia Química e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157, Oeiras, Portugal.,BioISI-Biosystems & Integrative Sciences Institute, University of Lisboa, Faculty of Sciences, Campo Grande, 1749-016 Lisboa, Portugal
| | - Patricia N Refojo
- Instituto de Tecnologia Química e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157, Oeiras, Portugal
| | - Manuela M Pereira
- Instituto de Tecnologia Química e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157, Oeiras, Portugal.,BioISI-Biosystems & Integrative Sciences Institute, University of Lisboa, Faculty of Sciences, Campo Grande, 1749-016 Lisboa, Portugal
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42
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Rational Design of an Artificial Nuclease by Engineering a Hetero-Dinuclear Center of Mg-Heme in Myoglobin. ACS Catal 2020. [DOI: 10.1021/acscatal.0c04572] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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43
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Mattes TE, Ingalls AE, Burke S, Morris RM. Metabolic flexibility of SUP05 under low DO growth conditions. Environ Microbiol 2020; 23:2823-2833. [PMID: 32893469 DOI: 10.1111/1462-2920.15226] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 09/02/2020] [Indexed: 11/30/2022]
Abstract
Chemoautotrophic bacteria from the SUP05 clade often dominate anoxic waters within marine oxygen minimum zones (OMZs) where they use energy gained from the oxidation of reduced sulfur to fuel carbon fixation. Some of these SUP05 bacteria are facultative aerobes that can use either nitrate or oxygen as a terminal electron acceptor making them ideally suited to thrive at the boundaries of OMZs where they experience fluctuations in dissolved oxygen (DO). SUP05 metabolism in these regions, and therefore the biogeochemical function of SUP05, depends largely on their sensitivity to oxygen. We evaluated growth and quantified differences in gene expression in Ca. T. autotrophicus strain EF1 from the SUP05 clade under high DO (22 μM), anoxic, and low DO (3.8 μM) concentrations. We show that strain EF1 cells respire oxygen and nitrate and that cells have higher growth rates, express more genes, and fix more carbon when oxygen becomes available for aerobic respiration. Evidence that facultatively aerobic SUP05 are more active and respire nitrate when oxygen becomes available at low concentrations suggests that they are an important source of nitrite across marine OMZ boundary layers.
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Affiliation(s)
- Timothy E Mattes
- Department of Civil and Environmental Engineering, 4105 Seamans Center, University of Iowa, Iowa City, IA, 52242, USA
| | - Anitra E Ingalls
- School of Oceanography, University of Washington, Seattle, WA, USA
| | - Susan Burke
- School of Oceanography, University of Washington, Seattle, WA, USA
| | - Robert M Morris
- School of Oceanography, University of Washington, Seattle, WA, USA
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44
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Esposti MD. On the evolution of cytochrome oxidases consuming oxygen. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1861:148304. [PMID: 32890468 DOI: 10.1016/j.bbabio.2020.148304] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 08/21/2020] [Accepted: 08/31/2020] [Indexed: 02/07/2023]
Abstract
This review examines the current state of the art on the evolution of the families of Heme Copper Oxygen reductases (HCO) that oxidize cytochrome c and reduce oxygen to water, chiefly cytochrome oxidase, COX. COX is present in many bacterial and most eukaryotic lineages, but its origin has remained elusive. After examining previous proposals for COX evolution, the review summarizes recent insights suggesting that COX enzymes might have evolved in soil dwelling, probably iron-oxidizing bacteria which lived on emerged land over two billion years ago. These bacteria were the likely ancestors of extant acidophilic iron-oxidizers such as Acidithiobacillus spp., which belong to basal lineages of the phylum Proteobacteria. Proteobacteria may thus be considered the originators of COX, which was then laterally transferred to other prokaryotes. The taxonomy of bacteria is presented in relation to the current distribution of COX and C family oxidases, from which COX may have evolved.
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Affiliation(s)
- Mauro Degli Esposti
- Center for Genomic Sciences UNAM, Ave. Universidad 701, Cuernavaca, CP 62130, Morelos, Mexico.
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45
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Melin F, Hellwig P. Redox Properties of the Membrane Proteins from the Respiratory Chain. Chem Rev 2020; 120:10244-10297. [DOI: 10.1021/acs.chemrev.0c00249] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Frederic Melin
- Chimie de la Matière Complexe UMR 7140, Laboratoire de Bioelectrochimie et Spectroscopie, CNRS-Université de Strasbourg, 1 rue Blaise Pascal, 67070 Strasbourg, France
| | - Petra Hellwig
- Chimie de la Matière Complexe UMR 7140, Laboratoire de Bioelectrochimie et Spectroscopie, CNRS-Université de Strasbourg, 1 rue Blaise Pascal, 67070 Strasbourg, France
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46
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Chen C, Wang Y, Liu H, Chen Y, Yao J, Chen J, Hrynsphanb D, Tatsianab S. Heterologous expression and functional study of nitric oxide reductase catalytic reduction peptide from Achromobacter denitrificans strain TB. CHEMOSPHERE 2020; 253:126739. [PMID: 32464773 DOI: 10.1016/j.chemosphere.2020.126739] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 01/21/2020] [Accepted: 04/04/2020] [Indexed: 06/11/2023]
Abstract
Biological denitrification is a promising and green technology for air pollution control. To investigate the nitric oxide reductase (NOR) that dominates NO reduction efficiency in biological purification, the heterologous prokaryotic expression system of the norB gene, which encodes the core peptide of the catalytic reduction structure in the NOR from Achromobacter denitrificans strain TB, was constructed in Escherichia coli BL21 (DE3). Results showed that the 1218 bp-long norB gene was expressed at the highest level under 1.0 mM IPTG for 5 h at 30 °C, and the relative expression abundance of norB in recombinant E. coli was increased by 16.6 times compared with that of the wild-type TB. However, the NO reduction efficiency and NOR activity of strain TB was 2.7 and 1.83 times higher than those of recombinant E. coli, respectively. On the basis of genomic reassembly and protein structure modeling, the core peptide of the NOR catalytic reduction structure from Achromobacter sp. TB can independently exert NO reduction. The low NO degradation efficiency of recombinant E. coli may be due to the lack of a NorC-like structure that increases the enzyme activity of the NorB protein. The results of this study can be used as basis for further research on the structure and function of NOR.
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Affiliation(s)
- Cong Chen
- College of Environmental, Zhejiang University of Technology, Hangzhou, 310032, PR China
| | - Yu Wang
- College of Environmental, Zhejiang University of Technology, Hangzhou, 310032, PR China
| | - Huan Liu
- College of Environmental, Zhejiang University of Technology, Hangzhou, 310032, PR China
| | - Yi Chen
- College of Environmental, Zhejiang University of Technology, Hangzhou, 310032, PR China
| | - Jiachao Yao
- College of Biological and Environmental Engineering, Zhejiang Shuren University, Hangzhou, 310021, PR China
| | - Jun Chen
- College of Biological and Environmental Engineering, Zhejiang Shuren University, Hangzhou, 310021, PR China.
| | - Dzmitry Hrynsphanb
- Research Institute of Physical and Chemical Problems, Belarusian State University, Minsk, 220030, Belarus
| | - Savitskaya Tatsianab
- Research Institute of Physical and Chemical Problems, Belarusian State University, Minsk, 220030, Belarus
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47
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Blomberg MRA. Role of the Two Metals in the Active Sites of Heme Copper Oxidases-A Study of NO Reduction in cbb3 Cytochrome c Oxidase. Inorg Chem 2020; 59:11542-11553. [PMID: 32799475 DOI: 10.1021/acs.inorgchem.0c01351] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The superfamily of heme copper oxidases reduces molecular oxygen or nitric oxide, and the active sites comprise a high-spin heme group (a3 or b3) and a non-heme metal (CuB or FeB). The cbb3 C family of cytochrome c oxidases, with the high-spin heme b3 and CuB in the active site, is a subfamily of the heme copper oxidases that can reduce both molecular oxygen, which is the main substrate, and nitric oxide. The mechanism for NO reduction in cbb3 oxidase is studied here using hybrid density functional theory and compared to other cytochrome c oxidases (A and B families), with a high-spin heme a3 and CuB in the active site, and to cytochrome c dependent NO reductase, with a high-spin heme b3 and a non-heme FeB in the active site. It is found that the reaction mechanism and the detailed reaction energetics of the cbb3 oxidases are not similar to those of cytochrome c dependent NO reductase, which has the same type of high-spin heme group but a different non-heme metal. This is in contrast to earlier expectations. Instead, the NO reduction mechanism in cbb3 oxidases is very similar to that in the other cytochrome c oxidases, with the same non-heme metal, CuB, and is independent of the type of high-spin heme group. The conclusion is that the type of non-heme metal (CuB or FeB) in the active site of the heme copper oxidases is more important for the reaction mechanisms than the type of high-spin heme, at least for the NO reduction reaction. The reason is that the proton-coupled reduction potentials of the active site cofactors determine the energetics for the NO reduction reaction, and they depend to a larger extent on the non-heme metal. Observed differences in NO reduction reactivity among the various cytochrome c oxidases may be explained by differences outside the BNC, affecting the rate of proton transfer, rather than in the BNC itself.
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48
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Flores-Tinoco CE, Tschan F, Fuhrer T, Margot C, Sauer U, Christen M, Christen B. Co-catabolism of arginine and succinate drives symbiotic nitrogen fixation. Mol Syst Biol 2020; 16:e9419. [PMID: 32490601 PMCID: PMC7268258 DOI: 10.15252/msb.20199419] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 04/13/2020] [Accepted: 04/21/2020] [Indexed: 12/22/2022] Open
Abstract
Biological nitrogen fixation emerging from the symbiosis between bacteria and crop plants holds promise to increase the sustainability of agriculture. One of the biggest hurdles for the engineering of nitrogen-fixing organisms is an incomplete knowledge of metabolic interactions between microbe and plant. In contrast to the previously assumed supply of only succinate, we describe here the CATCH-N cycle as a novel metabolic pathway that co-catabolizes plant-provided arginine and succinate to drive the energy-demanding process of symbiotic nitrogen fixation in endosymbiotic rhizobia. Using systems biology, isotope labeling studies and transposon sequencing in conjunction with biochemical characterization, we uncovered highly redundant network components of the CATCH-N cycle including transaminases that interlink the co-catabolism of arginine and succinate. The CATCH-N cycle uses N2 as an additional sink for reductant and therefore delivers up to 25% higher yields of nitrogen than classical arginine catabolism-two alanines and three ammonium ions are secreted for each input of arginine and succinate. We argue that the CATCH-N cycle has evolved as part of a synergistic interaction to sustain bacterial metabolism in the microoxic and highly acid environment of symbiosomes. Thus, the CATCH-N cycle entangles the metabolism of both partners to promote symbiosis. Our results provide a theoretical framework and metabolic blueprint for the rational design of plants and plant-associated organisms with new properties to improve nitrogen fixation.
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Affiliation(s)
| | - Flavia Tschan
- Institute of Molecular Systems Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland
| | - Tobias Fuhrer
- Institute of Molecular Systems Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland
| | - Céline Margot
- Institute of Molecular Systems Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland
| | - Uwe Sauer
- Institute of Molecular Systems Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland
| | - Matthias Christen
- Institute of Molecular Systems Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland
| | - Beat Christen
- Institute of Molecular Systems Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland
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49
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Integral caa 3-Cytochrome c Oxidase from Thermus thermophilus: Purification and Crystallization. Methods Mol Biol 2020. [PMID: 31342419 DOI: 10.1007/978-1-4939-9678-0_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Cytochrome c oxidase is a respiratory enzyme catalyzing the energy-conserving reduction of molecular oxygen to water-a fundamental biological process of cell respiration. The first crystal structures of the type A cytochrome c oxidases, bovine heart and Paracoccus denitrificans cytochrome c oxidases, were published in 1995 and contributed immensely to the understanding of the enzyme's mechanism of action. The senior author's research focus was directed toward understanding the structure and function of the type B cytochrome c oxidases, ba3-oxidase and type A2 caa3-oxidase, both from the extreme thermophilic bacterium Thermus thermophilus. While the ba3-oxidase structure was published in 2000 and functional characterization is well-documented in the literature, we recently successfully solved the structure of the caa3-nature made enzyme-substrate complex. This chapter is dedicated to the purification and crystallization process of caa3-cytochrome c oxidase.
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50
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Kwon H, Basran J, Devos JM, Suardíaz R, van der Kamp MW, Mulholland AJ, Schrader TE, Ostermann A, Blakeley MP, Moody PCE, Raven EL. Visualizing the protons in a metalloenzyme electron proton transfer pathway. Proc Natl Acad Sci U S A 2020; 117:6484-6490. [PMID: 32152099 PMCID: PMC7104402 DOI: 10.1073/pnas.1918936117] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
In redox metalloenzymes, the process of electron transfer often involves the concerted movement of a proton. These processes are referred to as proton-coupled electron transfer, and they underpin a wide variety of biological processes, including respiration, energy conversion, photosynthesis, and metalloenzyme catalysis. The mechanisms of proton delivery are incompletely understood, in part due to an absence of information on exact proton locations and hydrogen bonding structures in a bona fide metalloenzyme proton pathway. Here, we present a 2.1-Å neutron crystal structure of the complex formed between a redox metalloenzyme (ascorbate peroxidase) and its reducing substrate (ascorbate). In the neutron structure of the complex, the protonation states of the electron/proton donor (ascorbate) and all of the residues involved in the electron/proton transfer pathway are directly observed. This information sheds light on possible proton movements during heme-catalyzed oxygen activation, as well as on ascorbate oxidation.
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Affiliation(s)
- Hanna Kwon
- School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
| | - Jaswir Basran
- Department of Molecular and Cell Biology, University of Leicester, Leicester LE1 7RH, United Kingdom
- Leicester Institute of Structural and Chemical Biology, University of Leicester, Leicester LE1 7RH, United Kingdom
| | - Juliette M Devos
- Life Sciences Group, Institut Laue-Langevin, 38000 Grenoble, France
| | - Reynier Suardíaz
- School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
- School of Biochemistry, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Marc W van der Kamp
- School of Biochemistry, University of Bristol, Bristol BS8 1TD, United Kingdom
| | | | - Tobias E Schrader
- Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Forschungszentrum Jülich GmbH, 85748 Garching, Germany
| | - Andreas Ostermann
- Heinz Maier-Leibnitz Zentrum, Technische Universität München, D-85748 Garching, Germany
| | - Matthew P Blakeley
- Large-Scale Structures Group, Institut Laue-Langevin, 38000 Grenoble, France
| | - Peter C E Moody
- Department of Molecular and Cell Biology, University of Leicester, Leicester LE1 7RH, United Kingdom;
- Leicester Institute of Structural and Chemical Biology, University of Leicester, Leicester LE1 7RH, United Kingdom
| | - Emma L Raven
- School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom;
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