1
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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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2
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Li H, Akella S, Engstler C, Omini JJ, Rodriguez M, Obata T, Carrie C, Cerutti H, Mower JP. Recurrent evolutionary switches of mitochondrial cytochrome c maturation systems in Archaeplastida. Nat Commun 2024; 15:1548. [PMID: 38378784 PMCID: PMC10879542 DOI: 10.1038/s41467-024-45813-y] [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: 06/15/2023] [Accepted: 02/05/2024] [Indexed: 02/22/2024] Open
Abstract
Mitochondrial cytochrome c maturation (CCM) requires heme attachment via distinct pathways termed systems I and III. The mosaic distribution of these systems in Archaeplastida raises questions about the genetic mechanisms and evolutionary forces promoting repeated evolution. Here, we show a recurrent shift from ancestral system I to the eukaryotic-specific holocytochrome c synthase (HCCS) of system III in 11 archaeplastid lineages. Archaeplastid HCCS is sufficient to rescue mutants of yeast system III and Arabidopsis system I. Algal HCCS mutants exhibit impaired growth and respiration, and altered biochemical and metabolic profiles, likely resulting from deficient CCM and reduced cytochrome c-dependent respiratory activity. Our findings demonstrate that archaeplastid HCCS homologs function as system III components in the absence of system I. These results elucidate the evolutionary trajectory and functional divergence of CCM pathways in Archaeplastida, providing insight into the causes, mechanisms, and consequences of repeated cooption of an entire biological pathway.
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Affiliation(s)
- Huang Li
- Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Soujanya Akella
- Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Carina Engstler
- Department Biologie I-Botanik, Ludwig-Maximilians-Universität München, D-82152, Planegg-Martinsried, Germany
| | - Joy J Omini
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Moira Rodriguez
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Toshihiro Obata
- Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Chris Carrie
- School of Biological Sciences, University of Auckland, Auckland, 1142, New Zealand
| | - Heriberto Cerutti
- Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Jeffrey P Mower
- Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA.
- Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA.
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3
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Huynh JQ, Lowder EP, Kranz RG. Structural basis of membrane machines that traffick and attach heme to cytochromes. J Biol Chem 2023; 299:105332. [PMID: 37827288 PMCID: PMC10663686 DOI: 10.1016/j.jbc.2023.105332] [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: 08/31/2023] [Revised: 10/04/2023] [Accepted: 10/06/2023] [Indexed: 10/14/2023] Open
Abstract
We evaluate cryoEM and crystal structures of two molecular machines that traffick heme and attach it to cytochrome c (cyt c), the second activity performed by a cyt c synthase. These integral membrane proteins, CcsBA and CcmF/H, both covalently attach heme to cyt c, but carry it out via different mechanisms. A CcsB-CcsA complex transports heme through a channel to its external active site, where it forms two thioethers between reduced (Fe+2) heme and CysXxxXxxCysHis in cyt c. The active site is formed by a periplasmic WWD sequence and two histidines (P-His1 and P-His2). We evaluate each proposed functional domain in CcsBA cryoEM densities, exploring their presence in other CcsB-CcsA proteins from a wide distribution of organisms (e.g., from Gram positive to Gram negative bacteria to chloroplasts.) Two conserved pockets, for the first and second cysteines of CXXCH, explain stereochemical heme attachment. In addition to other universal features, a conserved periplasmic beta stranded structure, called the beta cap, protects the active site when external heme is not present. Analysis of CcmF/H, here called an oxidoreductase and cyt c synthase, addresses mechanisms of heme access and attachment. We provide evidence that CcmF/H receives Fe+3 heme from holoCcmE via a periplasmic entry point in CcmF, whereby heme is inserted directly into a conserved WWD/P-His domain from above. Evidence suggests that CcmF acts as a heme reductase, reducing holoCcmE (to Fe+2) through a transmembrane electron transfer conduit, which initiates a complicated series of events at the active site.
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Affiliation(s)
- Jonathan Q Huynh
- Department of Biology, Washington University, St. Louis, Missouri, USA
| | - Ethan P Lowder
- Department of Biology, Washington University, St. Louis, Missouri, USA
| | - Robert G Kranz
- Department of Biology, Washington University, St. Louis, Missouri, USA.
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4
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Karanth S, Pradhan AK. Development of a novel machine learning-based weighted modeling approach to incorporate Salmonella enterica heterogeneity on a genetic scale in a dose-response modeling framework. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2023; 43:440-450. [PMID: 35413139 DOI: 10.1111/risa.13924] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Estimating microbial dose-response is an important aspect of a food safety risk assessment. In recent years, there has been considerable interest to advance these models with potential incorporation of gene expression data. The aim of this study was to develop a novel machine learning model that considers the weights of expression of Salmonella genes that could be associated with illness, given exposure, in hosts. Here, an elastic net-based weighted Poisson regression method was proposed to identify Salmonella enterica genes that could be significantly associated with the illness response, irrespective of serovar. The best-fit elastic net model was obtained by 10-fold cross-validation. The best-fit elastic net model identified 33 gene expression-dose interaction terms that added to the predictability of the model. Of these, nine genes associated with Salmonella metabolism and virulence were found to be significant by the best-fit Poisson regression model (p < 0.05). This method could improve or redefine dose-response relationships for illness from relative proportions of significant genes from a microbial genetic dataset, which would help in refining endpoint and risk estimations.
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Affiliation(s)
- Shraddha Karanth
- Department of Nutrition and Food Science, University of Maryland, College Park, Maryland, USA
| | - Abani K Pradhan
- Department of Nutrition and Food Science, University of Maryland, College Park, Maryland, USA
- Center for Food Safety and Security Systems, University of Maryland, College Park, Maryland, USA
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5
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Cain RL, Webb IK. Online protein unfolding characterized by ion mobility electron capture dissociation mass spectrometry: cytochrome C from neutral and acidic solutions. Anal Bioanal Chem 2023; 415:749-758. [PMID: 36622393 DOI: 10.1007/s00216-022-04501-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 12/02/2022] [Accepted: 12/20/2022] [Indexed: 01/10/2023]
Abstract
Electrospray ionization mass spectrometry (ESI-MS) experiments, including ion mobility spectrometry mass spectrometry (ESI-IMS-MS) and electron capture dissociation (ECD) of proteins ionized from aqueous solutions, have been used for the study of solution-like structures of intact proteins. By mixing aqueous proteins with denaturants online before ESI, the amount of protein unfolding can be precisely controlled and rapidly analyzed, permitting the characterization of protein folding intermediates in protein folding pathways. Herein, we mixed various pH solutions online with aqueous cytochrome C for unfolding and characterizing its unfolding intermediates with ESI-MS charge state distribution measurements, IMS, and ECD. The presence of folding intermediates and unfolded cytochrome c structures were detected from changes in charge states, arrival time distributions (ATDs), and ECD. We also compared structures from nondenaturing and denaturing solution mixtures measured under "gentle" (i.e., low energy) ion transmission conditions with structures measured under "harsh" (i.e., higher energy) transmission. This work confirms that when using "gentle" instrument conditions, the gas-phase cytochrome c ions reflect attributes of the various solution-phase structures. However, "harsh" conditions that maximize ion transmission produce extended structures that no longer correlate with changes in solution structure.
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Affiliation(s)
- Rebecca L Cain
- Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, 46202, USA
| | - Ian K Webb
- Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, 46202, USA.
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
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6
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In situ electrosynthetic bacterial growth using electricity generated by a deep-sea hydrothermal vent. THE ISME JOURNAL 2023; 17:12-20. [PMID: 36151459 PMCID: PMC9751133 DOI: 10.1038/s41396-022-01316-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Revised: 08/28/2022] [Accepted: 09/01/2022] [Indexed: 11/08/2022]
Abstract
Electroautotrophic microorganisms have attracted great attention since they exhibit a new type of primary production. Here, in situ electrochemical cultivation was conducted using the naturally occurring electromotive forces at a deep-sea hydrothermal vent. The voltage and current generation originating from the resulting microbial activity was observed for 12 days of deployment, with fluctuation in response to tidal cycles. A novel bacterium belonging to the genus Thiomicrorhabdus dominated the microbial community specifically enriched on the cathode. Metagenomic analysis provided the draft genome of the bacterium and the gene repertoire indicated that the bacterium has the potential for thio-autotrophic growth, which is a typical physiological feature of the members of the genus, while the bacterium had a unique gene cluster encoding multi-heme cytochrome c proteins responsible for extracellular electron transfer. Herein, we propose this bacterium as a new species, specifically enriched during electricity generation, as 'Candidatus Thiomicrorhabdus electrophagus'. This finding suggests the natural occurrence of electrosynthetic microbial populations using the geoelectricity in deep-sea hydrothermal environments.
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7
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A Common Target of Nitrite and Nitric Oxide for Respiration Inhibition in Bacteria. Int J Mol Sci 2022; 23:ijms232213841. [PMID: 36430319 PMCID: PMC9697910 DOI: 10.3390/ijms232213841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 11/07/2022] [Accepted: 11/08/2022] [Indexed: 11/12/2022] Open
Abstract
Nitrite and nitric oxide (NO) are well-known bacteriostatic agents with similar biochemical properties. However, many studies have demonstrated that inhibition of bacterial growth by nitrite is independent of NO. Here, with Shewanella oneidensis as the research model because of its unusually high cytochrome (cyt) c content, we identify a common mechanism by which nitrite and NO compromise cyt c biosynthesis in bacteria, and thereby inhibit respiration. This is achieved by eliminating the inference of the cyclic adenosine monophosphate-catabolite repression protein (cAMP-Crp), a primary regulatory system that controls the cyt c content and whose activity is subjected to the repression of nitrite. Both nitrite and NO impair the CcmE of multiple bacteria, an essential heme chaperone of the System I cyt c biosynthesis apparatus. Given that bacterial targets of nitrite and NO differ enormously and vary even in the same genus, these observations underscore the importance of cyt c biosynthesis for the antimicrobial actions of nitrite and NO.
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8
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Li J, Zheng W, Gu M, Han L, Luo Y, Yu K, Sun M, Zong Y, Ma X, Liu B, Lowder EP, Mendez DL, Kranz RG, Zhang K, Zhu J. Structures of the CcmABCD heme release complex at multiple states. Nat Commun 2022; 13:6422. [PMID: 36307425 PMCID: PMC9616876 DOI: 10.1038/s41467-022-34136-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 10/14/2022] [Indexed: 12/25/2022] Open
Abstract
Cytochromes c use heme as a cofactor to carry electrons in respiration and photosynthesis. The cytochrome c maturation system I, consisting of eight membrane proteins (CcmABCDEFGH), results in the attachment of heme to cysteine residues of cytochrome c proteins. Since all c-type cytochromes are periplasmic, heme is first transported to a periplasmic heme chaperone, CcmE. A large membrane complex, CcmABCD has been proposed to carry out this transport and linkage to CcmE, yet the structural basis and mechanisms underlying the process are unknown. We describe high resolution cryo-EM structures of CcmABCD in an unbound form, in complex with inhibitor AMP-PNP, and in complex with ATP and heme. We locate the ATP-binding site in CcmA and the heme-binding site in CcmC. Based on our structures combined with functional studies, we propose a hypothetic model of heme trafficking, heme transfer to CcmE, and ATP-dependent release of holoCcmE from CcmABCD. CcmABCD represents an ABC transporter complex using the energy of ATP hydrolysis for the transfer of heme from one binding partner (CcmC) to another (CcmE).
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Affiliation(s)
- Jiao Li
- grid.410745.30000 0004 1765 1045School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, 210023 China ,grid.47100.320000000419368710Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511 USA
| | - Wan Zheng
- grid.410745.30000 0004 1765 1045School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, 210023 China
| | - Ming Gu
- grid.410745.30000 0004 1765 1045School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, 210023 China
| | - Long Han
- grid.47100.320000000419368710Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511 USA
| | - Yanmei Luo
- grid.410745.30000 0004 1765 1045School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, 210023 China
| | - Koukou Yu
- grid.410745.30000 0004 1765 1045School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, 210023 China
| | - Mengxin Sun
- grid.410745.30000 0004 1765 1045School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, 210023 China
| | - Yuliang Zong
- grid.410745.30000 0004 1765 1045School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, 210023 China
| | - Xiuxiu Ma
- grid.410745.30000 0004 1765 1045School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, 210023 China
| | - Bing Liu
- grid.410745.30000 0004 1765 1045School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, 210023 China
| | - Ethan P. Lowder
- grid.4367.60000 0001 2355 7002Department of Biology, Washington University in St. Louis, CB 1137, One Brookings Drive, St. Louis, MO 63130-4899 USA
| | - Deanna L. Mendez
- grid.4367.60000 0001 2355 7002Department of Biology, Washington University in St. Louis, CB 1137, One Brookings Drive, St. Louis, MO 63130-4899 USA
| | - Robert G. Kranz
- grid.4367.60000 0001 2355 7002Department of Biology, Washington University in St. Louis, CB 1137, One Brookings Drive, St. Louis, MO 63130-4899 USA
| | - Kai Zhang
- grid.47100.320000000419368710Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511 USA
| | - Jiapeng Zhu
- grid.410745.30000 0004 1765 1045School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, 210023 China
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9
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Koebke KJ, Pinter TBJ, Pitts WC, Pecoraro VL. Catalysis and Electron Transfer in De Novo Designed Metalloproteins. Chem Rev 2022; 122:12046-12109. [PMID: 35763791 PMCID: PMC10735231 DOI: 10.1021/acs.chemrev.1c01025] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
One of the hallmark advances in our understanding of metalloprotein function is showcased in our ability to design new, non-native, catalytically active protein scaffolds. This review highlights progress and milestone achievements in the field of de novo metalloprotein design focused on reports from the past decade with special emphasis on de novo designs couched within common subfields of bioinorganic study: heme binding proteins, monometal- and dimetal-containing catalytic sites, and metal-containing electron transfer sites. Within each subfield, we highlight several of what we have identified as significant and important contributions to either our understanding of that subfield or de novo metalloprotein design as a discipline. These reports are placed in context both historically and scientifically. General suggestions for future directions that we feel will be important to advance our understanding or accelerate discovery are discussed.
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Affiliation(s)
- Karl J. Koebke
- Department of Chemistry, University of Michigan Ann Arbor, MI 48109 USA
| | | | - Winston C. Pitts
- Department of Chemistry, University of Michigan Ann Arbor, MI 48109 USA
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10
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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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11
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Guo K, Feng X, Sun W, Han S, Wu S, Gao H. NapB Restores cytochrome c biosynthesis in bacterial dsbD-deficient mutants. Commun Biol 2022; 5:87. [PMID: 35064202 PMCID: PMC8782879 DOI: 10.1038/s42003-022-03034-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 01/05/2022] [Indexed: 11/10/2022] Open
Abstract
Cytochromes c (cyts c), essential for respiration and photosynthesis in eukaryotes, confer bacteria respiratory versatility for survival and growth in natural environments. In bacteria having a cyt c maturation (CCM) system, DsbD is required to mediate electron transport from the cytoplasm to CcmG of the Ccm apparatus. Here with cyt c-rich Shewanella oneidensis as the research model, we identify NapB, a cyt c per se, that suppresses the CCM defect of a dsbD mutant during anaerobiosis, when NapB is produced at elevated levels, a result of activation by cAMP-Crp. Data are then presented to suggest that NapB reduces CcmG, leading to the suppression. We further show that NapB proteins capable of rescuing CCM in the dsbD mutant form a small distinct clade. The study sheds light on multifunctionality of cyts c, and more importantly, unravels a self-salvation strategy through which bacteria have evolved to better adjust to the natural world. The DsbD protein is normally required for cytochrome c maturation (Ccm) in bacteria. With cytochrome c-rich Shewanella oneidensis as the research model, NapB, the small subunit of the nitrate reductase which is a cytochrome c per se, was found to suppress the Ccm defect resulting from DsbD loss under anaerobic conditions.
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12
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Wu J, Pan X, Xu S, Duan Y, Wang J, Wang J, Gao T, Zhang Y, Zhou M. A Defect in the Twin-Arginine Translocation Pathway Decreases the Tolerance of Xanthomonas campestris pv. campestris to Phenazines. PHYTOPATHOLOGY 2020; 110:1897-1907. [PMID: 32689906 DOI: 10.1094/phyto-03-20-0065-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Phenazine-1-carboxylic acid (PCA), a member of phenazines secreted by microorganisms, inhibits the growth of many bacteria and fungi. Xanthomonas campestris pv. campestris is the causal agent of black rot, the most important disease of cruciferous crops worldwide, and is more tolerant to PCA than other Xanthomonas species. Previous studies reported that reactive oxygen species (ROS) scavenging ability is involved in regulating the PCA tolerance of Xanthomonas species. Additionally, the cytochrome c maturation (CCM) system has been found to play a more important role in tolerance to phenazines than the ROS scavenging system. In this study, a highly PCA-sensitive insertion mutant of X. campestris pv. campestris, X-5, was identified and studied. The insertion site of X-5 was found to be in tatB gene (XC_4183), which encodes a subunit of the twin-arginine translocation (TAT) complex. Disruption of the three genes of TAT pathway resulted in decreased biological fitness and reduced tolerance to phenazines in comparison with the wild-type strain 8004. These results imply that the tolerance mechanism of the TAT pathway to phenazines is related to the CCM system, but not due to the ROS scavenging system. Furthermore, respiration-related characteristic tests and peptide analysis suggested that disruption of the TAT complex causes a defect in the cytochrome bc1 complex, which may be involved in the tolerance to phenazines. In summary, this study sheds new light on the critical role of the TAT pathway in influencing the fitness and phenazines tolerance of Xanthomonas species.
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Affiliation(s)
- Jian Wu
- College of Plant Protection, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, Nanjing, 210095, China
- Institute of Plant Protection and Agro Product Safety, Anhui Academy of Agricultural Sciences, Hefei, 230001, China
| | - Xiayan Pan
- College of Plant Protection, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, Nanjing, 210095, China
| | - Shu Xu
- College of Plant Protection, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yabing Duan
- College of Plant Protection, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, Nanjing, 210095, China
| | - Jueyu Wang
- College of Plant Protection, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, Nanjing, 210095, China
| | - Jianxin Wang
- College of Plant Protection, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, Nanjing, 210095, China
| | - Tongchun Gao
- Institute of Plant Protection and Agro Product Safety, Anhui Academy of Agricultural Sciences, Hefei, 230001, China
| | - Yong Zhang
- Institute of Plant Protection and Agro Product Safety, Anhui Academy of Agricultural Sciences, Hefei, 230001, China
| | - Mingguo Zhou
- College of Plant Protection, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, Nanjing, 210095, China
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13
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in 't Zandt MH, Frank J, Yilmaz P, Cremers G, Jetten MSM, Welte CU. Long-term enriched methanogenic communities from thermokarst lake sediments show species-specific responses to warming. FEMS MICROBES 2020; 1:xtaa008. [PMID: 37333957 PMCID: PMC10117432 DOI: 10.1093/femsmc/xtaa008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 10/14/2020] [Indexed: 04/05/2024] Open
Abstract
Thermokarst lakes are large potential greenhouse gas (GHG) sources in a changing Arctic. In a warming world, an increase in both organic matter availability and temperature is expected to boost methanogenesis and potentially alter the microbial community that controls GHG fluxes. These community shifts are, however, challenging to detect by resolution-limited 16S rRNA gene-based approaches. Here, we applied full metagenome sequencing on long-term thermokarst lake sediment enrichments on acetate and trimethylamine at 4°C and 10°C to unravel species-specific responses to the most likely Arctic climate change scenario. Substrate amendment was used to mimic the increased organic carbon availability upon permafrost thaw. By performing de novo assembly, we reconstructed five high-quality and five medium-quality metagenome-assembled genomes (MAGs) that represented 59% of the aligned metagenome reads. Seven bacterial MAGs belonged to anaerobic fermentative bacteria. Within the Archaea, the enrichment of methanogenic Methanosaetaceae/Methanotrichaceae under acetate amendment and Methanosarcinaceae under trimethylamine (TMA) amendment was not unexpected. Surprisingly, we observed temperature-specific methanogenic (sub)species responses with TMA amendment. These highlighted distinct and potentially functional climate-induced shifts could not be revealed with 16S rRNA gene-based analyses. Unraveling these temperature- and nutrient-controlled species-level responses is essential to better comprehend the mechanisms that underlie GHG production from Arctic lakes in a warming world.
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Affiliation(s)
- Michiel H in 't Zandt
- Department of Microbiology, Institute for Water and Wetland Research, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands
- Netherlands Earth System Science Centre, Utrecht University, Heidelberglaan 2, 3584 CS Utrecht, the Netherlands
| | - Jeroen Frank
- Department of Microbiology, Institute for Water and Wetland Research, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands
- Soehngen Institute of Anaerobic Microbiology, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands
| | - Polen Yilmaz
- Department of Microbiology, Institute for Water and Wetland Research, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands
| | - Geert Cremers
- Department of Microbiology, Institute for Water and Wetland Research, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands
| | - Mike S M Jetten
- Department of Microbiology, Institute for Water and Wetland Research, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands
- Netherlands Earth System Science Centre, Utrecht University, Heidelberglaan 2, 3584 CS Utrecht, the Netherlands
- Soehngen Institute of Anaerobic Microbiology, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands
| | - Cornelia U Welte
- Department of Microbiology, Institute for Water and Wetland Research, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands
- Soehngen Institute of Anaerobic Microbiology, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands
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14
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Complex Oxidation of Apocytochromes c during Bacterial Cytochrome c Maturation. Appl Environ Microbiol 2019; 85:AEM.01989-19. [PMID: 31585997 DOI: 10.1128/aem.01989-19] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 09/30/2019] [Indexed: 12/22/2022] Open
Abstract
c-Type cytochromes (cyts c) are proteins that contain covalently bound heme and that thus require posttranslational modification for activity, a process carried out by the cytochrome c (cyt c) maturation system (referred to as the Ccm system) in many Gram-negative bacteria. It has been established that during cyt c maturation (CCM), two cysteine thiols of the heme binding motif (CXXCH) within apocytochromes c (apocyts c) are first oxidized largely by DsbA to form a disulfide bond, which is later reduced through a thio-reductive pathway involving DsbD. However, the physiological impacts of DsbA proteins on CCM in fact vary significantly among bacteria. In this work, we used the cyt c-rich Gram-negative bacterium Shewanella oneidensis as the research model to clarify the roles of DsbA proteins in CCM. We show that in terms of the oxidation of apocyts c, DsbA proteins are an important but not critical factor, and, strikingly, oxygen is not either. By exploiting the DsbD-independent pathway, we identify DsbA1, DsbA2, and DsbA3 as oxidants contributing to the oxidation of apocyts c and reductants, such as cysteine, to be an effective antagonist against DsbA-independent oxidation. We further show that DsbB proteins are partially responsible for the reoxidization of reduced DsbA proteins. Overall, our results indicate that the DsbA-DsbB redox pair has a limited role in CCM, challenging the established notion that it is the main oxidant for apocyts c IMPORTANCE DsbA is a powerful oxidase that functions in the bacterial periplasm to introduce disulfide bonds in many proteins, including apocytochromes c It has been well established that although DsbA is not essential, it plays a primary role in cytochrome c maturation, based on studies in bacteria hosting several cyts c Here, with cyt c-rich S. oneidensis as a research model, we show that this is not always the case. Moreover, we demonstrate that DsbB is also not essential for cytochrome c maturation. These results underscore the need to identify oxidants other than DsbA/DsbB that are crucial in the oxidation of apocyts c in bacteria.
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15
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Bacterial nitrous oxide respiration: electron transport chains and copper transfer reactions. Adv Microb Physiol 2019; 75:137-175. [PMID: 31655736 DOI: 10.1016/bs.ampbs.2019.07.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Biologically catalyzed nitrous oxide (N2O, laughing gas) reduction to dinitrogen gas (N2) is a desirable process in the light of ever-increasing atmospheric concentrations of this important greenhouse gas and ozone depleting substance. A diverse range of bacterial species produce the copper cluster-containing enzyme N2O reductase (NosZ), which is the only known enzyme that converts N2O to N2. Based on phylogenetic analyses, NosZ enzymes have been classified into clade I or clade II and it has turned out that this differentiation is also applicable to nos gene clusters (NGCs) and some physiological traits of the corresponding microbial cells. The NosZ enzyme is the terminal reductase of anaerobic N2O respiration, in which electrons derived from a donor substrate are transferred to NosZ by means of an electron transport chain (ETC) that conserves energy through proton motive force generation. This chapter presents models of the ETCs involved in clade I and clade II N2O respiration as well as of the respective NosZ maturation and maintenance processes. Despite differences in NGCs and growth yields of N2O-respiring microorganisms, the deduced bioenergetic framework in clade I and clade II N2O respiration is assumed to be equivalent. In both cases proton motive quinol oxidation by N2O is thought to be catalyzed by the Q cycle mechanism of a membrane-bound Rieske/cytochrome bc complex. However, clade I and clade II organisms are expected to differ significantly in terms of auxiliary electron transport processes as well as NosZ active site maintenance and repair.
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16
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Yang H, Yamanaka M, Nagao S, Yasuhara K, Shibata N, Higuchi Y, Hirota S. Protein surface charge effect on 3D domain swapping in cells for c-type cytochromes. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2019; 1867:140265. [PMID: 31437585 DOI: 10.1016/j.bbapap.2019.140265] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 07/19/2019] [Accepted: 08/14/2019] [Indexed: 12/13/2022]
Abstract
Many c-type cytochromes (cyts) can form domain-swapped oligomers. The positively charged Hydrogenobacter thermophilus (HT) cytochrome (cyt) c552 forms domain-swapped oligomers during expression in the Escherichia coli (E. coli) expression system, but the factors influencing the oligomerization remain unrevealed. Here, we found that the dimer of the negatively charged Shewanella violacea (SV) cyt c5 exhibits a domain-swapped structure, in which the N-terminal helix is exchanged between protomers, similar to the structures of the HT cyt c552 and Pseudomonas aeruginosa (PA) cyt c551 domain-swapped dimers. Positively charged horse cyt c and HT cyt c552 domain swapped during expression in E. coli, whereas negatively charged PA cyt c551 and SV cyt c5 did not. Oligomers were formed during expression in E. coli for HT cyt c552 attached to either a co- or post-translational signal peptide for transportation through the cytoplasm membrane, but not for PA cyt c551 attached to either signal peptide. HT cyt c552 formed oligomers in E. coli in the presence and absence of rare codons. More oligomers were obtained from the in vitro folding of horse cyt c and HT cyt c552 by the addition of negatively charged liposomes during folding, whereas the amount of oligomers for the in vitro folding of PA cyt c551 and SV cyt c5 did not change significantly by the addition. These results indicate that the protein surface charge affects the oligomerization of c-type cyts in cells; positively charged c-type cyts assemble on a negatively charged membrane, inducing formation of domain-swapped oligomers during folding.
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Affiliation(s)
- Hongxu Yang
- Division of Materials Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
| | - Masaru Yamanaka
- Division of Materials Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
| | - Satoshi Nagao
- Division of Materials Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
| | - Kazuma Yasuhara
- Division of Materials Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
| | - Naoki Shibata
- Department of Life Science, Graduate School of Life Science, University of Hyogo, 3-2-1 Koto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan
| | - Yoshiki Higuchi
- Department of Life Science, Graduate School of Life Science, University of Hyogo, 3-2-1 Koto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan
| | - Shun Hirota
- Division of Materials Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan.
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Meyer EH, Welchen E, Carrie C. Assembly of the Complexes of the Oxidative Phosphorylation System in Land Plant Mitochondria. ANNUAL REVIEW OF PLANT BIOLOGY 2019; 70:23-50. [PMID: 30822116 DOI: 10.1146/annurev-arplant-050718-100412] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Plant mitochondria play a major role during respiration by producing the ATP required for metabolism and growth. ATP is produced during oxidative phosphorylation (OXPHOS), a metabolic pathway coupling electron transfer with ADP phosphorylation via the formation and release of a proton gradient across the inner mitochondrial membrane. The OXPHOS system is composed of large, multiprotein complexes coordinating metal-containing cofactors for the transfer of electrons. In this review, we summarize the current state of knowledge about assembly of the OXPHOS complexes in land plants. We present the different steps involved in the formation of functional complexes and the regulatory mechanisms controlling the assembly pathways. Because several assembly steps have been found to be ancestral in plants-compared with those described in fungal and animal models-we discuss the evolutionary dynamics that lead to the conservation of ancestral pathways in land plant mitochondria.
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Affiliation(s)
- Etienne H Meyer
- Organelle Biology and Biotechnology Research Group, Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
- Current affiliation: Institute of Plant Physiology, Martin-Luther-University Halle-Wittenberg, 06120 Halle, Germany;
| | - Elina Welchen
- Cátedra de Biología Celular y Molecular, Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, 3000 Santa Fe, Argentina
| | - Chris Carrie
- Plant Sciences Research Group, Department Biologie I, Ludwig-Maximilians-Universität, 82152 Planegg-Martinsried, Germany
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18
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Significance of MccR, MccC, MccD, MccL and 8-methylmenaquinone in sulfite respiration of Wolinella succinogenes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1860:12-21. [DOI: 10.1016/j.bbabio.2018.10.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 09/26/2018] [Accepted: 10/13/2018] [Indexed: 11/17/2022]
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19
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Abstract
The movement or trafficking of heme is critical for cellular functions (e.g., oxygen transport and energy production); however, intracellular heme is tightly regulated due to its inherent cytotoxicity. These factors, combined with the transient nature of transport, have resulted in a lack of direct knowledge on the mechanisms of heme binding and trafficking. Here, we used the cytochrome c biogenesis system II pathway as a model to study heme trafficking. System II is composed of two integral membrane proteins (CcsBA) which function to transport heme across the membrane and stereospecifically position it for covalent attachment to apocytochrome c. We mapped two heme binding domains in CcsBA and suggest a path for heme trafficking. These data, in combination with metagenomic coevolution data, are used to determine a structural model of CcsBA, leading to increased understanding of the mechanisms for heme transport and the cytochrome c synthetase function of CcsBA. Although intracellular heme trafficking must occur for heme protein assembly, only a few heme transporters have been unequivocally discovered and nothing is known about their structure or mechanisms. Cytochrome c biogenesis in prokaryotes requires the transport of heme from inside to outside for stereospecific attachment to cytochrome c via two thioether bonds (at CXXCH). The CcsBA integral membrane protein was shown to transport and attach heme (and thus is a cytochrome c synthetase), but the structure and mechanisms underlying these two activities are poorly understood. We employed a new cysteine/heme crosslinking tool that traps endogenous heme in heme binding sites. We combined these data with a comprehensive imidazole correction approach (for heme ligand interrogation) to map heme binding sites. Results illuminate the process of heme transfer through the membrane to an external binding site (called the WWD domain). Using meta-genomic data (GREMLIN) and Rosetta modeling programs, a structural model of the transmembrane (TM) regions in CcsBA were determined. The heme mapping data were then incorporated to model the TM heme binding site (with TM-His1 and TM-His2 as ligands) and the external heme binding WWD domain (with P-His1 and P-His2 as ligands). Other periplasmic structure/function studies facilitated modeling of the full CcsBA protein as a framework for understanding the mechanisms. Mechanisms are proposed for heme transport from TM-His to WWD/P-His and subsequent stereospecific attachment of heme. A ligand exchange of the P-His1 for histidine of CXXCH at the synthetase active site is suggested.
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20
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Shevket SH, Gonzalez D, Cartwright JL, Kleanthous C, Ferguson SJ, Redfield C, Mavridou DAI. The CcmC-CcmE interaction during cytochrome c maturation by System I is driven by protein-protein and not protein-heme contacts. J Biol Chem 2018; 293:16778-16790. [PMID: 30206118 PMCID: PMC6204919 DOI: 10.1074/jbc.ra118.005024] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 09/07/2018] [Indexed: 12/30/2022] Open
Abstract
Cytochromes c are ubiquitous proteins, essential for life in most organisms. Their distinctive characteristic is the covalent attachment of heme to their polypeptide chain. This post-translational modification is performed by a dedicated protein system, which in many Gram-negative bacteria and plant mitochondria is a nine-protein apparatus (CcmA-I) called System I. Despite decades of study, mechanistic understanding of the protein-protein interactions in this highly complex maturation machinery is still lacking. Here, we focused on the interaction of CcmC, the protein that sources the heme cofactor, with CcmE, the pivotal component of System I responsible for the transfer of the heme to the apocytochrome. Using in silico analyses, we identified a putative interaction site between these two proteins (residues Asp47, Gln50, and Arg55 on CcmC; Arg73, Asp101, and Glu105 on CcmE), and we validated our findings by in vivo experiments in Escherichia coli Moreover, employing NMR spectroscopy, we examined whether a heme-binding site on CcmE contributes to this interaction and found that CcmC and CcmE associate via protein-protein rather than protein-heme contacts. The combination of in vivo site-directed mutagenesis studies and high-resolution structural techniques enabled us to determine at the residue level the mechanism for the formation of one of the key protein complexes for cytochrome c maturation by System I.
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Affiliation(s)
- Shevket H Shevket
- the Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Diego Gonzalez
- the Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Quartier UNIL/Sorge, Lausanne, Switzerland
| | - Jared L Cartwright
- the Bioscience Technology Facility, Department of Biology, University of York, Wentworth Way, York YO10 5DD, United Kingdom
| | - Colin Kleanthous
- the Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Stuart J Ferguson
- the Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom,
| | - Christina Redfield
- the Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom,
| | - Despoina A I Mavridou
- From the MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, Kensington, London SW7 2DD, United Kingdom,
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21
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Influence of heme c attachment on heme conformation and potential. J Biol Inorg Chem 2018; 23:1073-1083. [PMID: 30143872 DOI: 10.1007/s00775-018-1603-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 08/16/2018] [Indexed: 10/28/2022]
Abstract
Heme c is characterized by its covalent attachment to a polypeptide. The attachment is typically to a CXXCH motif in which the two Cys form thioether bonds with the heme, "X" can be any amino acid other than Cys, and the His serves as a heme axial ligand. Some cytochromes c, however, contain heme attachment motifs with three or four intervening residues in a CX3CH or CX4CH motif. Here, the impacts of these variations in the heme attachment motif on heme ruffling and electronic structure are investigated by spectroscopically characterizing CX3CH and CX4CH variants of Hydrogenobacter thermophilus cytochrome c552. In addition, a novel CXCH variant is studied. 1H and 13C NMR, EPR, and resonance Raman spectra of the protein variants are analyzed to deduce the extent of ruffling using previously reported relationships between these spectral data and heme ruffling. In addition, the reduction potentials of these protein variants are measured using protein film voltammetry. The CXCH and CX4CH variants are found to have enhanced heme ruffling and lower reduction potentials. Implications of these results for the use of these noncanonical motifs in nature, and for the engineering of novel heme peptide structures, are discussed.
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22
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Giglio KM, Keohane CE, Stodghill PV, Steele AD, Fetzer C, Sieber SA, Filiatrault MJ, Wuest WM. Transcriptomic Profiling Suggests That Promysalin Alters the Metabolic Flux, Motility, and Iron Regulation in Pseudomonas putida KT2440. ACS Infect Dis 2018; 4:1179-1187. [PMID: 29801413 DOI: 10.1021/acsinfecdis.8b00041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Promysalin, a secondary metabolite produced by P. putida RW10S1, is a narrow-spectrum antibiotic that targets P. aeruginosa over other Pseudomonas spp. P. putida KT2440, a nonproducing strain, displays increased swarming motility and decreased pyoverdine production in the presence of exogenous promysalin. Herein, proteomic and transcriptomic experiments were used to provide insight about how promysalin elicits responses in PPKT2440 and rationalize its species selectivity. RNA-sequencing results suggest that promysalin affects PPKT2440 by (1) increasing swarming in a flagella-independent manner; (2) causing cells to behave as if they were experiencing an iron-deficient environment, and (3) shifting metabolism away from glucose conversion to pyruvate via the Entner-Doudoroff pathway. These findings highlight nature's ability to develop small molecules with specific targets, resulting in exquisite selectivity.
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Affiliation(s)
- Krista M. Giglio
- Emerging Pests and Pathogens
Research, United States Department of Agriculture, Agricultural Research
Service, 538 Tower Road, Ithaca, New York 14853, United States
| | - Colleen E. Keohane
- Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia 30322, United States
| | - Paul V. Stodghill
- Emerging Pests and Pathogens
Research, United States Department of Agriculture, Agricultural Research
Service, 538 Tower Road, Ithaca, New York 14853, United States
| | - Andrew D. Steele
- Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia 30322, United States
| | - Christian Fetzer
- Department of Chemistry, Center for Integrated Protein Science Munich (CIPSM), Technische Universität München, Lichtenbergstraße 4, 85747 Garching, Germany
| | - Stephan A. Sieber
- Department of Chemistry, Center for Integrated Protein Science Munich (CIPSM), Technische Universität München, Lichtenbergstraße 4, 85747 Garching, Germany
| | - Melanie J. Filiatrault
- Emerging Pests and Pathogens
Research, United States Department of Agriculture, Agricultural Research
Service, 538 Tower Road, Ithaca, New York 14853, United States
- School of Integrative Plant Science, Plant Pathology and Plant-Microbe Biology Section, Cornell University, 236 Tower Road, Ithaca, New York 14853, United States
| | - William M. Wuest
- Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia 30322, United States
- Emory Antibiotic Resistance Center, Emory University, 201 Dowman Drive, Atlanta, Georgia 30322, United States
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23
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Sharma V, Siedenburg G, Birke J, Mobeen F, Jendrossek D, Prakash T. Metabolic and taxonomic insights into the Gram-negative natural rubber degrading bacterium Steroidobacter cummioxidans sp. nov., strain 35Y. PLoS One 2018; 13:e0197448. [PMID: 29851965 PMCID: PMC5979037 DOI: 10.1371/journal.pone.0197448] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2017] [Accepted: 05/02/2018] [Indexed: 11/19/2022] Open
Abstract
The pathway of rubber (poly [cis-1,4-isoprene]) catabolism is well documented for Gram-positive rubber degraders but only little information exists for Gram-negative species. The first documented potent rubber degrading Gram-negative strain is Xanthomonas sp. strain 35Y that uses extracellular rubber oxygenases for the initial cleavage of the polyisoprene molecule. However, neither the exact phylogenetic position of Xanthomonas sp. strain 35Y nor the catabolic pathway of the primary polyisoprene cleavage products have been investigated. In this contribution, we started to address both these issues by a comprehensive taxonomic characterization and by the analysis of the draft genome sequence of strain 35Y. Evaluation of the 16S rRNA gene sequence pointed to a borderline taxonomic position of strain 35Y as a novel species of the genus Steroidobacter. Further, substantial differences in the genotypic properties of strain 35Y and the members of the genus Steroidobacter, including average nucleotide identity (ANI) and in silico DNA-DNA hybridization (DDH), resolved the taxonomic position of strain 35Y and suggested its positioning as a novel species of the genus Steroidobacter. This was further confirmed by comparative analysis of physiological and biochemical features of strain 35Y with other members of the genus Steroidobacter. Thus, we conclude that strain 35Y represents a novel species of the genus Steroidobacter, for which we propose the designation Steroidobacter cummioxidans sp. nov., strain 35YT. A comprehensive analysis of the draft genome of S. cummioxidans strain 35Y revealed similarities but also substantial differences to rubber degrading Gram-positive counterparts. In particular, the putative transporters for the uptake of polyisoprene cleavage products differ from Gram-positive rubber degrading species. The draft genome sequence of S. cummioxidans strain 35Y will be useful for researchers to experimentally verify the predicted similarities and differences in the pathways of polyisoprene catabolism in Gram-positive and Gram-negative rubber degrading species.
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Affiliation(s)
- Vikas Sharma
- School of Basic Sciences, Indian Institute of Technology (IIT) Mandi, Mandi, India
| | | | - Jakob Birke
- Institute of Microbiology, University of Stuttgart, Stuttgart, Germany
| | - Fauzul Mobeen
- School of Basic Sciences, Indian Institute of Technology (IIT) Mandi, Mandi, India
| | - Dieter Jendrossek
- Institute of Microbiology, University of Stuttgart, Stuttgart, Germany
| | - Tulika Prakash
- School of Basic Sciences, Indian Institute of Technology (IIT) Mandi, Mandi, India
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24
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Abstract
Although many putative heme transporters have been discovered, it has been challenging to prove that these proteins are directly involved with heme trafficking in vivo and to identify their heme binding domains. The prokaryotic pathways for cytochrome c biogenesis, Systems I and II, transport heme from inside the cell to outside for stereochemical attachment to cytochrome c, making them excellent models to study heme trafficking. System I is composed of eight integral membrane proteins (CcmA-H) and is proposed to transport heme via CcmC to an external "WWD" domain for presentation to the membrane-tethered heme chaperone, CcmE. Herein, we develop a new cysteine/heme crosslinking approach to trap and map endogenous heme in CcmC (WWD domain) and CcmE (defining "2-vinyl" and "4-vinyl" pockets for heme). Crosslinking occurs when either of the two vinyl groups of heme localize near a thiol of an engineered cysteine residue. Double crosslinking, whereby both vinyls crosslink to two engineered cysteines, facilitated a more detailed structural mapping of the heme binding sites, including stereospecificity. Using heme crosslinking results, heme ligand identification, and genomic coevolution data, we model the structure of the CcmCDE complex, including the WWD heme binding domain. We conclude that CcmC trafficks heme via its WWD domain and propose the structural basis for stereochemical attachment of heme.
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Balancing cellular redox metabolism in microbial electrosynthesis and electro fermentation - A chance for metabolic engineering. Metab Eng 2017; 45:109-120. [PMID: 29229581 DOI: 10.1016/j.ymben.2017.12.003] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 09/15/2017] [Accepted: 12/06/2017] [Indexed: 01/05/2023]
Abstract
More and more microbes are discovered that are capable of extracellular electron transfer, a process in which they use external electrodes as electron donors or acceptors for metabolic reactions. This feature can be used to overcome cellular redox limitations and thus optimizing microbial production. The technologies, termed microbial electrosynthesis and electro-fermentation, have the potential to open novel bio-electro production platforms from sustainable energy and carbon sources. However, the performance of reported systems is currently limited by low electron transport rates between microbes and electrodes and our limited ability for targeted engineering of these systems due to remaining knowledge gaps about the underlying fundamental processes. Metabolic engineering offers many opportunities to optimize these processes, for instance by genetic engineering of pathways for electron transfer on the one hand and target product synthesis on the other hand. With this review, we summarize the status quo of knowledge and engineering attempts around chemical production in bio-electrochemical systems from a microbe perspective. Challenges associated with the introduction or enhancement of extracellular electron transfer capabilities into production hosts versus the engineering of target compound synthesis pathways in natural exoelectrogens are discussed. Recent advances of the research community in both directions are examined critically. Further, systems biology approaches, for instance using metabolic modelling, are examined for their potential to provide insight into fundamental processes and to identify targets for metabolic engineering.
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Babbitt SE, Hsu J, Mendez DL, Kranz RG. Biosynthesis of Single Thioether c-Type Cytochromes Provides Insight into Mechanisms Intrinsic to Holocytochrome c Synthase (HCCS). Biochemistry 2017; 56:3337-3346. [PMID: 28617588 DOI: 10.1021/acs.biochem.7b00286] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
C-type cytochromes (cyts c) are generally characterized by the presence of two thioether attachments between heme and two cysteine residues within a highly conserved CXXCH motif. Most eukaryotes use the System III cyt c biogenesis pathway composed of holocytochrome c synthase (HCCS) to catalyze thioether formation. Some protozoan organisms express a functionally equivalent, natural variant of cyt c with an XXXCH heme-attachment motif, resulting in a single covalent attachment. Previous studies have shown that recombinant HCCS can produce low levels of the XXXCH single thioether variant. However, cyt c variants containing substitutions at the C-terminal cysteine of the heme-attachment site (i.e., resulting in CXXXH) have never been observed in nature, and attempts to biosynthesize a recombinant version of this cyt c variant have been largely unsuccessful. In this study, we report the biochemical analyses of an HCCS-matured CXXXH cyt c variant, comparing its biosynthesis and properties to those of the XXXCH variant. The results indicate that although HCCS mediates heme attachment to the N-terminal cysteine in CXXXH cyt c variants, up to 50% of the cyt c produced is modified in an oxygen-dependent manner, resulting in a mixed population of cyt c. Since this aerobic modification occurs only in the context of CXXXH, we also propose that natural HCCS-mediated heme attachment to CXXCH likely initiates at the C-terminal cysteine.
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Affiliation(s)
- Shalon E Babbitt
- Department of Biology, Washington University , St. Louis, Missouri 63130, United States
| | - Jennifer Hsu
- Department of Biology, Washington University , St. Louis, Missouri 63130, United States
| | - Deanna L Mendez
- Department of Biology, Washington University , St. Louis, Missouri 63130, United States
| | - Robert G Kranz
- Department of Biology, Washington University , St. Louis, Missouri 63130, United States
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Dalecki AG, Crawford CL, Wolschendorf F. Copper and Antibiotics: Discovery, Modes of Action, and Opportunities for Medicinal Applications. Adv Microb Physiol 2017; 70:193-260. [PMID: 28528648 DOI: 10.1016/bs.ampbs.2017.01.007] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Copper is a ubiquitous element in the environment as well as living organisms, with its redox capabilities and complexation potential making it indispensable for many cellular functions. However, these same properties can be highly detrimental to prokaryotes and eukaryotes when not properly controlled, damaging many biomolecules including DNA, lipids, and proteins. To restrict free copper concentrations, all bacteria have developed mechanisms of resistance, sequestering and effluxing labile copper to minimize its deleterious effects. This weakness is actively exploited by phagocytes, which utilize a copper burst to destroy pathogens. Though administration of free copper is an unreasonable therapeutic antimicrobial itself, due to insufficient selectivity between host and pathogen, small-molecule ligands may provide an opportunity for therapeutic mimicry of the immune system. By modulating cellular entry, complex stability, resistance evasion, and target selectivity, ligand/metal coordination complexes can synergistically result in high levels of antibacterial activity. Several established therapeutic drugs, such as disulfiram and pyrithione, display remarkable copper-dependent inhibitory activity. These findings have led to development of new drug discovery techniques, using copper ions as the focal point. High-throughput screens for copper-dependent inhibitors against Mycobacterium tuberculosis and Staphylococcus aureus uncovered several new compounds, including a new class of inhibitors, the NNSNs. In this review, we highlight the microbial biology of copper, its antibacterial activities, and mechanisms to discover new inhibitors that synergize with copper.
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Affiliation(s)
- Alex G Dalecki
- The University of Alabama at Birmingham, Birmingham, AL, United States
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McCarver AC, Lessner FH, Soroeta JM, Lessner DJ. Methanosarcina acetivorans utilizes a single NADPH-dependent thioredoxin system and contains additional thioredoxin homologues with distinct functions. MICROBIOLOGY-SGM 2017; 163:62-74. [PMID: 27902413 DOI: 10.1099/mic.0.000406] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The thioredoxin system plays a central role in the intracellular redox maintenance in the majority of cells. The canonical system consists of an NADPH-dependent thioredoxin reductase (TrxR) and thioredoxin (Trx), a disulfide reductase. Although Trx is encoded in almost all sequenced genomes of methanogens, its incorporation into their unique physiology is not well understood. Methanosarcina acetivorans contains a single TrxR (MaTrxR) and seven Trx (MaTrx1-MaTrx7) homologues. We previously showed that MaTrxR and at least MaTrx7 compose a functional NADPH-dependent thioredoxin system. Here, we report the characterization of all seven recombinant MaTrxs. MaTrx1, MaTrx3, MaTrx4 and MaTrx5 lack appreciable disulfide reductase activity, unlike previously characterized MaTrx2, MaTrx6 and MaTrx7. Enzyme assays demonstrated that, of the MaTrxs, only the reduction of disulfide-containing MaTrx7 is linked to the oxidation of reduced coenzymes. NADPH is shown to be supplied to the MaTrxR-MaTrx7 system through the oxidation of the primary methanogen electron carriers F420H2 and ferredoxin, indicating that it serves as a primary intracellular reducing system in M. acetivorans. Bioinformatic analyses also indicate that the majority of methanogens likely utilize an NADPH-dependent thioredoxin system. The remaining MaTrxs may have specialized functions. MaTrx1 and MaTrx3 exhibited thiol oxidase activity. MaTrx3 and MaTrx6 are targeted to the membrane of M. acetivorans and likely function in the formation and the reduction of disulfides in membrane and/or extracellular proteins, respectively. This work provides insight into the incorporation of Trx into the metabolism of methanogens, and this reveals that methanogens contain Trx homologues with alternative properties and activities.
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Affiliation(s)
- Addison C McCarver
- Department of Biological Sciences, University of Arkansas-Fayetteville, Fayetteville, AR 72701, USA
| | - Faith H Lessner
- Department of Biological Sciences, University of Arkansas-Fayetteville, Fayetteville, AR 72701, USA
| | - Jose M Soroeta
- Department of Biological Sciences, University of Arkansas-Fayetteville, Fayetteville, AR 72701, USA
| | - Daniel J Lessner
- Department of Biological Sciences, University of Arkansas-Fayetteville, Fayetteville, AR 72701, USA
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29
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Babbitt SE, Hsu J, Kranz RG. Molecular Basis Behind Inability of Mitochondrial Holocytochrome c Synthase to Mature Bacterial Cytochromes: DEFINING A CRITICAL ROLE FOR CYTOCHROME c α HELIX-1. J Biol Chem 2016; 291:17523-34. [PMID: 27387500 DOI: 10.1074/jbc.m116.741231] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Indexed: 11/06/2022] Open
Abstract
Mitochondrial holocytochrome c synthase (HCCS) is required for cytochrome c (cyt c) maturation and therefore respiration. HCCS efficiently attaches heme via two thioethers to CXXCH of mitochondrial but not bacterial cyt c even though they are functionally conserved. This inability is due to residues in the bacterial cyt c N terminus, but the molecular basis is unknown. Human cyts c with deletions of single residues in α helix-1, which mimic bacterial cyt c, are poorly matured by human HCCS. Focusing on ΔM13 cyt c, we co-purified this variant with HCCS, demonstrating that HCCS recognizes the bacterial-like cytochrome. Although an HCCS-WT cyt c complex contains two covalent links, HCCS-ΔM13 cyt c contains only one thioether attachment. Using multiple approaches, we show that the single attachment is to the second thiol of C(15)SQC(18)H, indicating that α helix-1 is required for positioning the first cysteine for covalent attachment, whereas the histidine of CXXCH positions the second cysteine. Modeling of the N-terminal structure suggested that the serine residue (of CSQCH) would be anchored where the first cysteine should be in ΔM13 cyt c An engineered cyt c with a CQCH motif in the ΔM13 background is matured at higher levels (2-3-fold), providing further evidence for α helix-1 positioning the first cysteine. Bacterial cyt c biogenesis pathways (Systems I and II) appear to recognize simply the CXXCH motif, not requiring α helix-1. Results here explain mechanistically how HCCS (System III) requires an extended region adjacent to CXXCH for maturation.
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Affiliation(s)
- Shalon E Babbitt
- From the Department of Biology, Washington University, St. Louis, Missouri 63130
| | - Jennifer Hsu
- From the Department of Biology, Washington University, St. Louis, Missouri 63130
| | - Robert G Kranz
- From the Department of Biology, Washington University, St. Louis, Missouri 63130
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30
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Larsen Ø, Karlsen OA. Transcriptomic profiling of Methylococcus capsulatus (Bath) during growth with two different methane monooxygenases. Microbiologyopen 2016; 5:254-67. [PMID: 26687591 PMCID: PMC4831470 DOI: 10.1002/mbo3.324] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 11/04/2015] [Accepted: 11/06/2015] [Indexed: 11/23/2022] Open
Abstract
Methylococcus capsulatus (Bath) is a methanotroph that possesses both a membrane-embedded (pMMO) and a soluble methane monooxygenase (sMMO). The expression of these two MMO's is tightly controlled by the availability of copper in the growth medium, but the underlying mechanisms and the number of genes involved in this switch in methane oxidation is not yet fully elucidated. Microarray analyses were used to assess the transcriptome in cells producing either pMMO or sMMO. A total of 137 genes were differentially expressed, with 87 genes showing a significant up-regulation during sMMO production. The majority of the differentially expressed genes could be assigned to functional roles in the energy metabolism and transport. Furthermore, three copper responding gene clusters were discovered, including an extended cluster that also harbors the genes for sMMO. Our data also indicates that major changes takes place in the respiratory chain between pMMO- and sMMO-producing cells, and that quinone are predominantly used as the electron donors for methane oxidation by pMMO. Intriguingly, a large proportion of the differentially expressed genes between pMMO- and sMMO-producing cells encode c-type cytochromes. By combining microarray- and mass spectrometry data, a total of 35 c-type cytochromes are apparently expressed in M. capsulatus when grown in nitrate mineral salt medium with methane as sole energy and carbon source, and the expression of 21 of these respond to the availability of copper. Interestingly, several of these c-type cytochromes are recovered from the cell surface, suggesting that extracellular electron transfers may occur in M. capsulatus.
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Affiliation(s)
- Øivind Larsen
- Uni Research EnvironmentThormøhlensgate 49bBergen5006Norway
| | - Odd A. Karlsen
- Department of Molecular BiologyUniversity of BergenBergenNorway
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31
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Lin Y, Kardos J, Imai M, Ikenoue T, Kinoshita M, Sugiki T, Ishimori K, Goto Y, Lee YH. Amorphous Aggregation of Cytochrome c with Inherently Low Amyloidogenicity Is Characterized by the Metastability of Supersaturation and the Phase Diagram. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:2010-2022. [PMID: 26824789 DOI: 10.1021/acs.langmuir.5b03810] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Despite extensive studies on the folding and function of cytochrome c, the mechanisms underlying its aggregation remain largely unknown. We herein examined the aggregation behavior of the physiologically relevant two types of cytochrome c, metal-bound cytochrome c, and its fragment with high amyloidogenicity as predicted in alcohol/water mixtures. Although the aggregation propensity of holo cytochrome c was low due to high solubility, markedly unfolded apo cytochrome c, lacking the heme prosthetic group, strongly promoted the propensity for amorphous aggregation with increases in hydrophobicity. Silver-bound apo cytochrome c increased the capacity of fibrillar aggregation (i.e., protofibrils or immature fibrils) due to subtle structural changes of apo cytochrome c by strong binding of silver. However, mature amyloid fibrils were not detected for any of the cytochrome c variants or its fragment, even with extensive ultrasonication, which is a powerful amyloid inducer. These results revealed the intrinsically low amyloidogenicity of cytochrome c, which is beneficial for its homeostasis and function by facilitating the folding and minimizing irreversible amyloid formation. We propose that intrinsically low amyloidogenicity of cytochrome c is attributed to the low metastability of supersaturation. The phase diagram constructed based on solubility and aggregate type is useful for a comprehensive understanding of protein aggregation. Furthermore, amorphous aggregation, which is also viewed as a generic property of proteins, and amyloid fibrillation can be distinguished from each other by the metastability of supersaturation.
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Affiliation(s)
- Yuxi Lin
- Institute for Protein Research, Osaka University , Yamadaoka 3-2, Suita, Osaka 565-0871, Japan
| | - József Kardos
- MTA-ELTE NAP B Neuroimmunology Research Group, Department of Biochemistry, Eötvös Loránd University , Budapest H-1117, Hungary
| | - Mizue Imai
- Graduate School of Chemical Sciences and Engineering, Hokkaido University , Kita 13, Nishi 8, Kita-ku, Sapporo 060-8628, Japan
| | - Tatsuya Ikenoue
- Institute for Protein Research, Osaka University , Yamadaoka 3-2, Suita, Osaka 565-0871, Japan
| | - Misaki Kinoshita
- Institute for Protein Research, Osaka University , Yamadaoka 3-2, Suita, Osaka 565-0871, Japan
| | - Toshihiko Sugiki
- Institute for Protein Research, Osaka University , Yamadaoka 3-2, Suita, Osaka 565-0871, Japan
| | - Koichiro Ishimori
- Graduate School of Chemical Sciences and Engineering, Hokkaido University , Kita 13, Nishi 8, Kita-ku, Sapporo 060-8628, Japan
| | - Yuji Goto
- Institute for Protein Research, Osaka University , Yamadaoka 3-2, Suita, Osaka 565-0871, Japan
| | - Young-Ho Lee
- Institute for Protein Research, Osaka University , Yamadaoka 3-2, Suita, Osaka 565-0871, Japan
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32
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Barupala DP, Dzul SP, Riggs-Gelasco PJ, Stemmler TL. Synthesis, delivery and regulation of eukaryotic heme and Fe-S cluster cofactors. Arch Biochem Biophys 2016; 592:60-75. [PMID: 26785297 PMCID: PMC4784227 DOI: 10.1016/j.abb.2016.01.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 01/13/2016] [Accepted: 01/14/2016] [Indexed: 11/25/2022]
Abstract
In humans, the bulk of iron in the body (over 75%) is directed towards heme- or Fe-S cluster cofactor synthesis, and the complex, highly regulated pathways in place to accomplish biosynthesis have evolved to safely assemble and load these cofactors into apoprotein partners. In eukaryotes, heme biosynthesis is both initiated and finalized within the mitochondria, while cellular Fe-S cluster assembly is controlled by correlated pathways both within the mitochondria and within the cytosol. Iron plays a vital role in a wide array of metabolic processes and defects in iron cofactor assembly leads to human diseases. This review describes progress towards our molecular-level understanding of cellular heme and Fe-S cluster biosynthesis, focusing on the regulation and mechanistic details that are essential for understanding human disorders related to the breakdown in these essential pathways.
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Affiliation(s)
- Dulmini P Barupala
- Departments of Biochemistry and Molecular Biology, and Pharmaceutical Sciences, Wayne State University, Detroit, MI 48201, USA
| | - Stephen P Dzul
- Departments of Biochemistry and Molecular Biology, and Pharmaceutical Sciences, Wayne State University, Detroit, MI 48201, USA
| | | | - Timothy L Stemmler
- Departments of Biochemistry and Molecular Biology, and Pharmaceutical Sciences, Wayne State University, Detroit, MI 48201, USA.
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Hayashi Y, Yamanaka M, Nagao S, Komori H, Higuchi Y, Hirota S. Domain swapping oligomerization of thermostable c-type cytochrome in E. coli cells. Sci Rep 2016; 6:19334. [PMID: 26838805 PMCID: PMC4738263 DOI: 10.1038/srep19334] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Accepted: 12/07/2015] [Indexed: 01/21/2023] Open
Abstract
Knowledge on domain swapping in vitro is increasing, but domain swapping may not occur regularly in vivo, and its information in cells is limited. Herein, we show that domain-swapped oligomers of a thermostable c-type cytochrome, Hydrogenobacter thermophilus cyt c552, are formed in E. coli which expresses cyt c552. The region containing the N-terminal α-helix and heme was domain-swapped between protomers in the dimer formed in E. coli. The amount of cyt c552 oligomers increased in E. coli as the cyt c552 concentration was increased, whereas that of high-order oligomers decreased in the order of decrease in protein stability, indicating that domain swapping decreases in cells when the protein stability decreases. Apo cyt c552 was detected in the cyt c552 oligomer formed in E. coli, but not in that of the A5F/M11V/Y32F/Y41E/I76V mutant. The cyt c552 oligomer containing its apo protein may form at the periplasm, since the apo protein detected by mass measurements did not contain the signal peptide. These results show that domain-swapped cyt c552 oligomers were formed in E. coli, owing to the stability of the transient oligomer containing the apo protein before heme attachment. This is an indication that exceedingly stable proteins may have disadvantages forming domain-swapped oligomers in cells.
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Affiliation(s)
- Yugo Hayashi
- Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
| | - Masaru Yamanaka
- Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
| | - Satoshi Nagao
- Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
| | - Hirofumi Komori
- Faculty of Education, Kagawa University, 1-1 Saiwai, Takamatsu, Kagawa 760-8522, Japan
| | - Yoshiki Higuchi
- Department of Life Science, Graduate School of Life Science, University of Hyogo, 3-2-1 Koto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan.,RIKEN SPring-8 Center, 1-1-1 Koto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Shun Hirota
- Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
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Khalfaoui-Hassani B, Verissimo AF, Shroff NP, Ekici S, Trasnea PI, Utz M, Koch HG, Daldal F. Biogenesis of Cytochrome c Complexes: From Insertion of Redox Cofactors to Assembly of Different Subunits. ADVANCES IN PHOTOSYNTHESIS AND RESPIRATION 2016. [DOI: 10.1007/978-94-017-7481-9_27] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Watkins DW, Armstrong CT, Beesley JL, Marsh JE, Jenkins JMX, Sessions RB, Mann S, Ross Anderson JL. A suite of de novo c-type cytochromes for functional oxidoreductase engineering. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1857:493-502. [PMID: 26556173 DOI: 10.1016/j.bbabio.2015.11.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 10/30/2015] [Accepted: 11/06/2015] [Indexed: 10/22/2022]
Abstract
Central to the design of an efficient de novo enzyme is a robust yet mutable protein scaffold. The maquette approach to protein design offers precisely this, employing simple four-α-helix bundle scaffolds devoid of evolutionary complexity and with proven tolerance towards iterative protein engineering. We recently described the design of C2, a de novo designed c-type cytochrome maquette that undergoes post-translational modification in E. coli to covalently graft heme onto the protein backbone in vivo. This de novo cytochrome is capable of reversible oxygen binding, an obligate step in the catalytic cycle of many oxygen-activating oxidoreductases. Here we demonstrate the flexibility of both the maquette platform and the post-translational machinery of E. coli by creating a suite of functional de novo designed c-type cytochromes. We explore the engineering tolerances of the maquette by selecting alternative binding sites for heme C attachment and creating di-heme maquettes either by appending an additional heme C binding motif to the maquette scaffold or by binding heme B through simple bis-histidine ligation to a second binding site. The new designs retain the essential properties of the parent design but with significant improvements in structural stability. Molecular dynamics simulations aid the rationalization of these functional improvements while providing insight into the rules for engineering heme C binding sites in future iterations. This versatile, functional suite of de novo c-type cytochromes shows significant promise in providing robust platforms for the future engineering of de novo oxygen-activating oxidoreductases. This article is part of a Special Issue entitled Biodesign for Bioenergetics--the design and engineering of electron transfer cofactors, proteins and protein networks, edited by Ronald L. Koder and J.L. Ross Anderson.
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Affiliation(s)
- Daniel W Watkins
- School of Biochemistry, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Craig T Armstrong
- School of Biochemistry, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Joseph L Beesley
- School of Biochemistry, University of Bristol, University Walk, Bristol BS8 1TD, UK; School of Chemistry, University of Bristol, Bristol BS8 1TS, UK
| | - Jane E Marsh
- School of Biochemistry, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Jonathan M X Jenkins
- School of Biochemistry, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Richard B Sessions
- School of Biochemistry, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Stephen Mann
- School of Chemistry, University of Bristol, Bristol BS8 1TS, UK
| | - J L Ross Anderson
- School of Biochemistry, University of Bristol, University Walk, Bristol BS8 1TD, UK.
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Biochemical and functional characterization of a periplasmic disulfide oxidoreductase from Neisseria meningitidis essential for meningococcal viability. Biochem J 2015; 468:271-82. [PMID: 25826614 DOI: 10.1042/bj20140868] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
TlpAs (thioredoxin-like proteins) are bacterial thioredoxin-like periplasmic disulfide oxidoreductases generally involved in cytochrome c maturation (Ccm) process. They contain a characteristic CXXC active site motif involved in disulfide exchange reaction. In the human pathogenic Neisseria meningitidis species, no TlpA has been characterized so far. In the present study, using an in silico analysis, we identified a putative periplasmic TlpA, called TlpA2. Biochemical and kinetic characterizations of the soluble form of TlpA2, tTlpA2 (truncated TlpA2), were performed. A reduction potential of -0.230 V at pH 7 was calculated, suggesting that TlpA2 acts as a reductant in the oxidative environment of the periplasm. Using a second-order reactive probe, high pKapp (apparent pKa) values were determined for the two cysteines of the SCXXC motif. The tTlpA2 was shown to be efficiently reduced by the N-terminal domain of the DsbD, whereas tTlpA2 reduced a mimetic peptide of cytochrome c' with a catalytic efficiency similar to that observed with other disulfide oxidoreductase like ResA. Moreover, the corresponding gene tlpA2 was shown to be essential for the pathogen viability and able to partially complement a Bordetella pertussis CcsX mutant. Together, these data support an essential role of TlpA2 in the Ccm process in N. meningitidis.
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37
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Lin YW. The broad diversity of heme-protein cross-links: An overview. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2015; 1854:844-59. [DOI: 10.1016/j.bbapap.2015.04.019] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 03/26/2015] [Accepted: 04/17/2015] [Indexed: 12/30/2022]
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38
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Babbitt SE, Sutherland MC, San Francisco B, Mendez DL, Kranz RG. Mitochondrial cytochrome c biogenesis: no longer an enigma. Trends Biochem Sci 2015; 40:446-55. [PMID: 26073510 DOI: 10.1016/j.tibs.2015.05.006] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 05/13/2015] [Accepted: 05/18/2015] [Indexed: 12/31/2022]
Abstract
Cytochromes c (cyt c) and c1 are heme proteins that are essential for aerobic respiration. Release of cyt c from mitochondria is an important signal in apoptosis initiation. Biogenesis of c-type cytochromes involves covalent attachment of heme to two cysteines (at a conserved CXXCH sequence) in the apocytochrome. Heme attachment is catalyzed in most mitochondria by holocytochrome c synthase (HCCS), which is also necessary for the import of apocytochrome c (apocyt c). Thus, HCCS affects cellular levels of cyt c, impacting mitochondrial physiology and cell death. Here, we review the mechanisms of HCCS function and the roles of heme and residues in the CXXCH motif. Additionally, we consider concepts emerging within the two prokaryotic cytochrome c biogenesis pathways.
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Affiliation(s)
- Shalon E Babbitt
- Department of Biology, Washington University, St Louis, MO 63130, USA
| | | | | | - Deanna L Mendez
- Department of Biology, Washington University, St Louis, MO 63130, USA
| | - Robert G Kranz
- Department of Biology, Washington University, St Louis, MO 63130, USA.
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Kletzin A, Heimerl T, Flechsler J, van Niftrik L, Rachel R, Klingl A. Cytochromes c in Archaea: distribution, maturation, cell architecture, and the special case of Ignicoccus hospitalis. Front Microbiol 2015; 6:439. [PMID: 26029183 PMCID: PMC4429474 DOI: 10.3389/fmicb.2015.00439] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 04/23/2015] [Indexed: 01/25/2023] Open
Abstract
Cytochromes c (Cytc) are widespread electron transfer proteins and important enzymes in the global nitrogen and sulfur cycles. The distribution of Cytc in more than 300 archaeal proteomes deduced from sequence was analyzed with computational methods including pattern and similarity searches, secondary and tertiary structure prediction. Two hundred and fifty-eight predicted Cytc (with single, double, or multiple heme c attachment sites) were found in some but not all species of the Desulfurococcales, Thermoproteales, Archaeoglobales, Methanosarcinales, Halobacteriales, and in two single-cell genome sequences of the Thermoplasmatales, all of them Cren- or Euryarchaeota. Other archaeal phyla including the Thaumarchaeota are so far free of these proteins. The archaeal Cytc sequences were bundled into 54 clusters of mutual similarity, some of which were specific for Archaea while others had homologs in the Bacteria. The cytochrome c maturation system I (CCM) was the only one found. The highest number and variability of Cytc were present in those species with known or predicted metal oxidation and/or reduction capabilities. Paradoxical findings were made in the haloarchaea: several Cytc had been purified biochemically but corresponding proteins were not found in the proteomes. The results are discussed with emphasis on cell morphologies and envelopes and especially for double-membraned Archaea-like Ignicoccus hospitalis. A comparison is made with compartmentalized bacteria such as the Planctomycetes of the Anammox group with a focus on the putative localization and roles of the Cytc and other electron transport proteins.
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Affiliation(s)
- Arnulf Kletzin
- Department of Biology, Sulfur Biochemistry and Microbial Bioenergetics, Technische Universität Darmstadt Darmstadt, Germany
| | - Thomas Heimerl
- Fakultät für Biologie und Vorklinische Medizin, Zentrum für Elektronenmikroskopie, Universität Regensburg Regensburg, Germany
| | - Jennifer Flechsler
- Fakultät für Biologie und Vorklinische Medizin, Zentrum für Elektronenmikroskopie, Universität Regensburg Regensburg, Germany
| | - Laura van Niftrik
- Department of Microbiology, Institute for Water and Wetland Research, Radboud University Nijmegen Nijmegen, Netherlands
| | - Reinhard Rachel
- Fakultät für Biologie und Vorklinische Medizin, Zentrum für Elektronenmikroskopie, Universität Regensburg Regensburg, Germany
| | - Andreas Klingl
- Department of Biology I, Plant Development, Biocenter LMU Munich Planegg-Martinsried, Germany
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40
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Fu H, Jin M, Wan F, Gao H. Shewanella oneidensis cytochrome c maturation component CcmI is essential for heme attachment at the non-canonical motif of nitrite reductase NrfA. Mol Microbiol 2014; 95:410-25. [PMID: 25402661 DOI: 10.1111/mmi.12865] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/12/2014] [Indexed: 11/28/2022]
Abstract
Shewanella oneidensis is renowned for its respiratory versatility, which is largely due to abundant c-type cytochromes. Maturation of these proteins depends on a Ccm system encoded by genes in an unusual chromosomal arrangement, but the detailed mechanism is not understood. In this study, we identify SO0265 as CcmI, an apocytochrome c chaperone that is important and essential for maturation of c-type cytochromes with the canonical heme binding motif(s) (HBM; CX(2)CH) and nitrite reductase NrfA carrying a non-canonical CX(2)CK motif respectively. We show that the N-terminal transmembrane segment of CcmI, CcmI-1, is sufficient for maturation of the former but the entire protein is required for maturation of the latter. Although S. oneidensis possesses a heme lyase, SirEFG, dedicated for non-canonical HBMs, it is specific for SirA, a sulfite reductase with a CX(15)CH motif. By presenting evidence that the periplasmic portion of CcmI, CcmI-2, interacts with NrfA, we suggest that CcmI also takes the role of Escherichia coli NrfG for chaperoning apo-NrfA for maturation at CX(2)CK. Moreover, intact CcmI is required for maturation of NrfA, presumably by ensuring that heme attachment at canonical HBMs occurs before apoprotein degradation.
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Affiliation(s)
- Huihui Fu
- Institute of Microbiology and College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
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41
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Babbitt SE, San Francisco B, Bretsnyder EC, Kranz RG. Conserved residues of the human mitochondrial holocytochrome c synthase mediate interactions with heme. Biochemistry 2014; 53:5261-71. [PMID: 25054239 PMCID: PMC4139152 DOI: 10.1021/bi500704p] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
C-type cytochromes are distinguished by the covalent attachment of a heme cofactor, a modification that is typically required for its subsequent folding, stability, and function. Heme attachment takes place in the mitochondrial intermembrane space and, in most eukaryotes, is mediated by holocytochrome c synthase (HCCS). HCCS is the primary component of the eukaryotic cytochrome c biogenesis pathway, known as System III. The catalytic function of HCCS depends on its ability to coordinate interactions between its substrates: heme and cytochrome c. Recent advancements in the recombinant expression and purification of HCCS have facilitated comprehensive analyses of the roles of conserved residues in HCCS, as demonstrated in this study. Previously, we proposed a four-step model describing HCCS-mediated cytochrome c assembly, identifying a conserved histidine residue (His154) as an axial ligand to the heme iron. In this study, we performed a systematic mutational analysis of 17 conserved residues in HCCS, and we provide evidence that the enzyme contains two heme-binding domains. Our data indicate that heme contacts mediated by residues within these domains modulate the dynamics of heme binding and contribute to the stability of the HCCS-heme-cytochrome c steady state ternary complex. While some residues are essential for initial heme binding (step 1), others impact the subsequent release of the holocytochrome c product (step 4). Certain HCCS mutants that were defective in heme binding were corrected for function by exogenous aminolevulinic acid (ALA, the precursor to heme). This chemical "correction" supports the proposed role of heme binding for the corresponding residues.
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Affiliation(s)
- Shalon E Babbitt
- Department of Biology, Washington University , St. Louis, Missouri 63130, United States
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42
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Fu H, Jin M, Ju L, Mao Y, Gao H. Evidence for function overlapping of CymA and the cytochrome bc1 complex in the Shewanella oneidensis nitrate and nitrite respiration. Environ Microbiol 2014; 16:3181-95. [PMID: 24650148 DOI: 10.1111/1462-2920.12457] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 02/23/2014] [Accepted: 03/16/2014] [Indexed: 11/29/2022]
Abstract
Shewanella oneidensis is an important model organism for its versatility of anaerobic respiration. CymA, a cytoplasmic membrane-bound tetraheme c-type cytochrome, plays a central role in anaerobic respiration by transferring electrons from the quinone pool to a variety of terminal reductases. Although loss of CymA results in defect in respiration of many electron acceptors (EAs), a significant share of the capacity remains in general. In this study, we adopted a transposon random mutagenesis method in a cymA null mutant to identify substituent(s) of CymA with respect to nitrite and nitrate respiration. A total of 87 insertion mutants, whose ability to reduce nitrite was further impaired, were obtained. Among the interrupted genes, the petABC operon appeared to be the most likely candidate given the involvement of the cytochrome bc1 complex that it encodes in electron transport. Subsequent analyses not only confirmed that the complex and CymA were indeed functionally overlapping in nitrate/nitrite respiration but also revealed that both proteins were able to draw electrons from ubiquinone and menaquinone. Furthermore, we found that expression of the bc1 complex was affected by oxygen but not nitrate or nitrite and by global regulators ArcA and Crp in an indirect manner.
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Affiliation(s)
- Huihui Fu
- Institute of Microbiology and College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
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43
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Naß B, Pöll U, Langer JD, Kreuter L, Küper U, Flechsler J, Heimerl T, Rachel R, Huber H, Kletzin A. Three multihaem cytochromes c from the hyperthermophilic archaeon Ignicoccus hospitalis: purification, properties and localization. MICROBIOLOGY-SGM 2014; 160:1278-1289. [PMID: 24705227 DOI: 10.1099/mic.0.077792-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Three different multihaem cytochromes c were purified from cell extracts of the hyperthermophilic archaeon Ignicoccus hospitalis. One tetrahaem cytochrome, locus tag designation Igni_0530, was purified from membrane fractions together with the iron-sulfur protein Igni_0529. Two octahaem cytochromes, Igni_0955 and Igni_1359, were purified from soluble fractions but were also present in the membrane fraction. N-terminal sequencing showed that three of the four proteins had their signal peptides cleaved off, while results were ambiguous for Igni_0955. In contrast, mass spectrometry of Igni_0955 and Igni_1359 resulted in single mass peaks including the signal sequences and eight haems per subunit and so both forms might be present in the cell. Igni_0955 and Igni_1359 belong to the hydroxylamine dehydrogenase (HAO) family (29 % mutual identity). HAO or reductase activities with inorganic sulfur compounds were not detected. Igni_0955 was reduced by enriched I. hospitalis hydrogenase at a specific activity of 243 nmol min(-1) (mg hydrogenase)(-1) while activity was non-existent for Igni_0530 and low for Igni_1359. Immuno-electron microscopy of ultra-thin sections showed that Igni_0955 and Igni_1359 are located in both I. hospitalis membranes and also in the intermembrane compartment. We concluded that these cytochromes might function as electron shuttles between the hydrogenase in the outer cellular membrane and cellular reductases, whereas Igni_0530 might be part of the sulfur-reducing mechanism.
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Affiliation(s)
- Bastian Naß
- Technische Universität Darmstadt, Microbiology - Sulfur Biochemistry and Microbial Bioenergetics, Darmstadt, Germany
| | - Uwe Pöll
- Technische Universität Darmstadt, Microbiology - Sulfur Biochemistry and Microbial Bioenergetics, Darmstadt, Germany
| | - Julian David Langer
- Max Planck Institute of Biophysics, Max-von-Laue-Straße 3, 60438 Frankfurt am Main, Germany
| | - Lydia Kreuter
- Lehrstuhl für Mikrobiologie, Universität Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Ulf Küper
- Lehrstuhl für Mikrobiologie, Universität Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Jennifer Flechsler
- Zentrum für Elektronenmikroskopie, Universität Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Thomas Heimerl
- Zentrum für Elektronenmikroskopie, Universität Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Reinhard Rachel
- Zentrum für Elektronenmikroskopie, Universität Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Harald Huber
- Lehrstuhl für Mikrobiologie, Universität Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Arnulf Kletzin
- Technische Universität Darmstadt, Microbiology - Sulfur Biochemistry and Microbial Bioenergetics, Darmstadt, Germany
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Verissimo AF, Daldal F. Cytochrome c biogenesis System I: an intricate process catalyzed by a maturase supercomplex? BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:989-98. [PMID: 24631867 DOI: 10.1016/j.bbabio.2014.03.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2014] [Revised: 03/03/2014] [Accepted: 03/06/2014] [Indexed: 11/16/2022]
Abstract
Cytochromes c are ubiquitous heme proteins that are found in most living organisms and are essential for various energy production pathways as well as other cellular processes. Their biosynthesis relies on a complex post-translational process, called cytochrome c biogenesis, responsible for the formation of stereo-specific thioether bonds between the vinyl groups of heme b (protoporphyrin IX-Fe) and the thiol groups of apocytochromes c heme-binding site (C1XXC2H) cysteine residues. In some organisms this process involves up to nine (CcmABCDEFGHI) membrane proteins working together to achieve heme ligation, designated the Cytochrome c maturation (Ccm)-System I. Here, we review recent findings related to the Ccm-System I found in bacteria, archaea and plant mitochondria, with an emphasis on protein interactions between the Ccm components and their substrates (apocytochrome c and heme). We discuss the possibility that the Ccm proteins may form a multi subunit supercomplex (dubbed "Ccm machine"), and based on the currently available data, we present an updated version of a mechanistic model for Ccm. This article is part of a Special Issue entitled: 18th European Bioenergetic Conference.
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Affiliation(s)
- Andreia F Verissimo
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104-6019, USA
| | - Fevzi Daldal
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104-6019, USA.
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Mavridou DAI, Saridakis E, Kritsiligkou P, Mozley EC, Ferguson SJ, Redfield C. An extended active-site motif controls the reactivity of the thioredoxin fold. J Biol Chem 2014; 289:8681-96. [PMID: 24469455 PMCID: PMC3961690 DOI: 10.1074/jbc.m113.513457] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Proteins belonging to the thioredoxin (Trx) superfamily are abundant in all organisms. They share the same structural features, arranged in a seemingly simple fold, but they perform a multitude of functions in oxidative protein folding and electron transfer pathways. We use the C-terminal domain of the unique transmembrane reductant conductor DsbD as a model for an in-depth analysis of the factors controlling the reactivity of the Trx fold. We employ NMR spectroscopy, x-ray crystallography, mutagenesis, in vivo functional experiments applied to DsbD, and a comparative sequence analysis of Trx-fold proteins to determine the effect of residues in the vicinity of the active site on the ionization of the key nucleophilic cysteine of the -CXXC- motif. We show that the function and reactivity of Trx-fold proteins depend critically on the electrostatic features imposed by an extended active-site motif.
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Affiliation(s)
- Despoina A I Mavridou
- From the Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom and
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46
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Wong KS, Snider JD, Graham C, Greenblatt JF, Emili A, Babu M, Houry WA. The MoxR ATPase RavA and its cofactor ViaA interact with the NADH:ubiquinone oxidoreductase I in Escherichia coli. PLoS One 2014; 9:e85529. [PMID: 24454883 PMCID: PMC3893208 DOI: 10.1371/journal.pone.0085529] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 11/27/2013] [Indexed: 12/26/2022] Open
Abstract
MoxR ATPases are widespread throughout bacteria and archaea. The experimental evidence to date suggests that these proteins have chaperone-like roles in facilitating the maturation of dedicated protein complexes that are functionally diverse. In Escherichia coli, the MoxR ATPase RavA and its putative cofactor ViaA are found to exist in early stationary-phase cells at 37 °C at low levels of about 350 and 90 molecules per cell, respectively. Both proteins are predominantly localized to the cytoplasm, but ViaA was also unexpectedly found to localize to the cell membrane. Whole genome microarrays and synthetic lethality studies both indicated that RavA-ViaA are genetically linked to Fe-S cluster assembly and specific respiratory pathways. Systematic analysis of mutant strains of ravA and viaA indicated that RavA-ViaA sensitizes cells to sublethal concentrations of aminoglycosides. Furthermore, this effect was dependent on RavA's ATPase activity, and on the presence of specific subunits of NADH:ubiquinone oxidoreductase I (Nuo Complex, or Complex I). Importantly, both RavA and ViaA were found to physically interact with specific Nuo subunits. We propose that RavA-ViaA facilitate the maturation of the Nuo complex.
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Affiliation(s)
- Keith S. Wong
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Jamie D. Snider
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Chris Graham
- Department of Biochemistry, Research and Innovation Centre, University of Regina, Regina, Saskatchewan, Canada
| | - Jack F. Greenblatt
- Banting and Best Department of Medical Research, Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
| | - Andrew Emili
- Banting and Best Department of Medical Research, Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
| | - Mohan Babu
- Department of Biochemistry, Research and Innovation Centre, University of Regina, Regina, Saskatchewan, Canada
| | - Walid A. Houry
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
- * E-mail:
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Abstract
The global biogeochemical nitrogen cycle is essential for life on Earth. Many of the underlying biotic reactions are catalyzed by a multitude of prokaryotic and eukaryotic life forms whereas others are exclusively carried out by microorganisms. The last century has seen the rise of a dramatic imbalance in the global nitrogen cycle due to human behavior that was mainly caused by the invention of the Haber-Bosch process. Its main product, ammonia, is a chemically reactive and biotically favorable form of bound nitrogen. The anthropogenic supply of reduced nitrogen to the biosphere in the form of ammonia, for example during environmental fertilization, livestock farming, and industrial processes, is mandatory in feeding an increasing world population. In this chapter, environmental ammonia pollution is linked to the activity of microbial metalloenzymes involved in respiratory energy metabolism and bioenergetics. Ammonia-producing multiheme cytochromes c are discussed as paradigm enzymes.
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Affiliation(s)
- Jörg Simon
- Microbial Energy Conversion and Biotechnology, Department of Biology, Technische Universität Darmstadt, Schnittspahnstrasse 10, D-64287, Darmstadt, Germany,
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48
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Mavridou DAI, Clark MN, Choulat C, Ferguson SJ, Stevens JM. Probing heme delivery processes in cytochrome c biogenesis System I. Biochemistry 2013; 52:7262-70. [PMID: 24044352 PMCID: PMC3806149 DOI: 10.1021/bi400398t] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
![]()
Cytochromes c comprise
a diverse and widespread
family of proteins containing covalently bound heme that are central
to the life of most organisms. In many bacteria and in certain mitochondria,
the synthesis of cytochromes c is performed by a
complex post-translational modification apparatus called System I
(or cytochrome c maturation, Ccm, system). In Escherichia coli, there are eight maturation proteins,
several of which are involved in heme handling, but the mechanism
of heme transfer from one protein to the next is not known. Attachment
of the heme to the apocytochrome occurs via a novel covalent bond
to a histidine residue of the heme chaperone CcmE. The discovery of
a variant maturation system (System I*) has provided a new tool for
studying cytochrome c assembly because the variant
CcmE functions via a cysteine residue in the place of the histidine
of System I. In this work, we use site-directed mutagenesis on both
maturation systems to probe the function of the individual component
proteins as well as their concerted action in transferring heme to
the cytochrome c substrate. The roles of CcmA, CcmC,
CcmE, and CcmF in the heme delivery process are compared between Systems
I and I*. We show that a previously proposed quinone-binding site
on CcmF is not essential for either system. Significant differences
in the heme chemistry involved in the formation of cytochromes c in the variant system add new pieces to the cytochrome c biogenesis puzzle.
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Affiliation(s)
- Despoina A I Mavridou
- Department of Biochemistry, University of Oxford , South Parks Road, Oxford OX1 3QU, United Kingdom
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49
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The Tll0287 protein is a hemoprotein associated with the PsbA2-Photosystem II complex in Thermosynechococcus elongatus. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2013; 1827:1174-82. [DOI: 10.1016/j.bbabio.2013.06.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Revised: 05/27/2013] [Accepted: 06/05/2013] [Indexed: 12/14/2022]
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Jin M, Jiang Y, Sun L, Yin J, Fu H, Wu G, Gao H. Unique organizational and functional features of the cytochrome c maturation system in Shewanella oneidensis. PLoS One 2013; 8:e75610. [PMID: 24040415 PMCID: PMC3769277 DOI: 10.1371/journal.pone.0075610] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Accepted: 08/16/2013] [Indexed: 11/19/2022] Open
Abstract
Shewanella are renowned for their ability to respire on a wide range of electron acceptors, which has been partially accredited to the presence of a large number of the c-type cytochromes. In the model species S. oneidensis MR-1, at least 41 genes encode c-type cytochromes that are predicted to be intact, thereby likely functional. Previously, in-frame deletion mutants for 36 of these genes were obtained and characterized. In this study, first we completed the construction of an entire set of c-type cytochrome mutants utilizing a newly developed att-based mutagenesis approach, which is more effective and efficient than the approach used previously by circumventing the conventional cloning. Second, we investigated the cytochrome c maturation (Ccm) system in S. oneidensis. There are two loci predicted to encode components of the Ccm system, SO0259-SO0269 and SO0476-SO0478. The former is proven essential for cytochrome c maturation whereas the latter is dispensable. Unlike the single operon organization observed in other γ-proteobacteria, genes at the SO0259-SO0269 locus are uniquely organized into four operons, ccmABCDE, scyA, SO0265, and ccmFGH-SO0269. Functional analysis revealed that the SO0265 gene rather than the scyA and SO0269 genes are relevant to cytochrome c maturation.
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Affiliation(s)
- Miao Jin
- College of Life Sciences and Institute of Microbiology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yaoming Jiang
- College of Life Sciences and Institute of Microbiology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Linlin Sun
- College of Life Sciences and Institute of Microbiology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jianhua Yin
- College of Life Sciences and Institute of Microbiology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Huihui Fu
- College of Life Sciences and Institute of Microbiology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Genfu Wu
- College of Life Sciences and Institute of Microbiology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Haichun Gao
- College of Life Sciences and Institute of Microbiology, Zhejiang University, Hangzhou, Zhejiang, China
- * E-mail:
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