1
|
Ding K, Chin M, Zhao Y, Huang W, Mai BK, Wang H, Liu P, Yang Y, Luo Y. Machine learning-guided co-optimization of fitness and diversity facilitates combinatorial library design in enzyme engineering. Nat Commun 2024; 15:6392. [PMID: 39080249 PMCID: PMC11289365 DOI: 10.1038/s41467-024-50698-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: 05/29/2024] [Accepted: 07/19/2024] [Indexed: 08/02/2024] Open
Abstract
The effective design of combinatorial libraries to balance fitness and diversity facilitates the engineering of useful enzyme functions, particularly those that are poorly characterized or unknown in biology. We introduce MODIFY, a machine learning (ML) algorithm that learns from natural protein sequences to infer evolutionarily plausible mutations and predict enzyme fitness. MODIFY co-optimizes predicted fitness and sequence diversity of starting libraries, prioritizing high-fitness variants while ensuring broad sequence coverage. In silico evaluation shows that MODIFY outperforms state-of-the-art unsupervised methods in zero-shot fitness prediction and enables ML-guided directed evolution with enhanced efficiency. Using MODIFY, we engineer generalist biocatalysts derived from a thermostable cytochrome c to achieve enantioselective C-B and C-Si bond formation via a new-to-nature carbene transfer mechanism, leading to biocatalysts six mutations away from previously developed enzymes while exhibiting superior or comparable activities. These results demonstrate MODIFY's potential in solving challenging enzyme engineering problems beyond the reach of classic directed evolution.
Collapse
Affiliation(s)
- Kerr Ding
- School of Computational Science and Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Michael Chin
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, 93106, USA
| | - Yunlong Zhao
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, 93106, USA
| | - Wei Huang
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, 93106, USA
| | - Binh Khanh Mai
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Huanan Wang
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, 93106, USA
| | - Peng Liu
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, 15260, USA.
| | - Yang Yang
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, 93106, USA.
- Biomolecular Science and Engineering (BMSE) Program, University of California, Santa Barbara, CA, 93106, USA.
| | - Yunan Luo
- School of Computational Science and Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
| |
Collapse
|
2
|
Zhou Z, Arroum T, Luo X, Kang R, Lee YJ, Tang D, Hüttemann M, Song X. Diverse functions of cytochrome c in cell death and disease. Cell Death Differ 2024; 31:387-404. [PMID: 38521844 PMCID: PMC11043370 DOI: 10.1038/s41418-024-01284-8] [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: 10/07/2023] [Revised: 03/13/2024] [Accepted: 03/18/2024] [Indexed: 03/25/2024] Open
Abstract
The redox-active protein cytochrome c is a highly positively charged hemoglobin that regulates cell fate decisions of life and death. Under normal physiological conditions, cytochrome c is localized in the mitochondrial intermembrane space, and its distribution can extend to the cytosol, nucleus, and extracellular space under specific pathological or stress-induced conditions. In the mitochondria, cytochrome c acts as an electron carrier in the electron transport chain, facilitating adenosine triphosphate synthesis, regulating cardiolipin peroxidation, and influencing reactive oxygen species dynamics. Upon cellular stress, it can be released into the cytosol, where it interacts with apoptotic peptidase activator 1 (APAF1) to form the apoptosome, initiating caspase-dependent apoptotic cell death. Additionally, following exposure to pro-apoptotic compounds, cytochrome c contributes to the survival of drug-tolerant persister cells. When translocated to the nucleus, it can induce chromatin condensation and disrupt nucleosome assembly. Upon its release into the extracellular space, cytochrome c may act as an immune mediator during cell death processes, highlighting its multifaceted role in cellular biology. In this review, we explore the diverse structural and functional aspects of cytochrome c in physiological and pathological responses. We summarize how posttranslational modifications of cytochrome c (e.g., phosphorylation, acetylation, tyrosine nitration, and oxidation), binding proteins (e.g., HIGD1A, CHCHD2, ITPR1, and nucleophosmin), and mutations (e.g., G41S, Y48H, and A51V) affect its function. Furthermore, we provide an overview of the latest advanced technologies utilized for detecting cytochrome c, along with potential therapeutic approaches related to this protein. These strategies hold tremendous promise in personalized health care, presenting opportunities for targeted interventions in a wide range of conditions, including neurodegenerative disorders, cardiovascular diseases, and cancer.
Collapse
Affiliation(s)
- Zhuan Zhou
- Department of Surgery, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Tasnim Arroum
- Center for Molecular Medicine and Genetics, Wayne State University, Detroit, MI, 48201, USA
| | - Xu Luo
- Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Rui Kang
- Department of Surgery, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Yong J Lee
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Los Angeles, CA, 90048, USA
| | - Daolin Tang
- Department of Surgery, UT Southwestern Medical Center, Dallas, TX, 75390, USA.
| | - Maik Hüttemann
- Center for Molecular Medicine and Genetics, Wayne State University, Detroit, MI, 48201, USA.
- Department of Biochemistry, Microbiology, and Immunology, Wayne State University, Detroit, MI, 48201, USA.
| | - Xinxin Song
- Department of Surgery, UT Southwestern Medical Center, Dallas, TX, 75390, USA.
| |
Collapse
|
3
|
Yu L, Min Z, Liu M, Xin Y, Liu A, Kuang J, Wu W, Wu J, He H, Xin J, Blankenship RE, Tian C, Xu X. A cytochrome c 551 mediates the cyclic electron transport chain of the anoxygenic phototrophic bacterium Roseiflexus castenholzii. PLANT COMMUNICATIONS 2024; 5:100715. [PMID: 37710959 PMCID: PMC10873879 DOI: 10.1016/j.xplc.2023.100715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 06/27/2023] [Accepted: 09/08/2023] [Indexed: 09/16/2023]
Abstract
Roseiflexus castenholzii is a gram-negative filamentous phototrophic bacterium that carries out anoxygenic photosynthesis through a cyclic electron transport chain (ETC). The ETC is composed of a reaction center (RC)-light-harvesting (LH) complex (rcRC-LH); an alternative complex III (rcACIII), which functionally replaces the cytochrome bc1/b6f complex; and the periplasmic electron acceptor auracyanin (rcAc). Although compositionally and structurally different from the bc1/b6f complex, rcACIII plays similar essential roles in oxidizing menaquinol and transferring electrons to the rcAc. However, rcACIII-mediated electron transfer (which includes both an intraprotein route and a downstream route) has not been clearly elucidated, nor have the details of cyclic ETC. Here, we identify a previously unknown monoheme cytochrome c (cyt c551) as a novel periplasmic electron acceptor of rcACIII. It reduces the light-excited rcRC-LH to complete a cyclic ETC. We also reveal the molecular mechanisms involved in the ETC using electron paramagnetic resonance (EPR), spectroelectrochemistry, and enzymatic and structural analyses. We find that electrons released from rcACIII-oxidized menaquinol are transferred to two alternative periplasmic electron acceptors (rcAc and cyt c551), which eventually reduce the rcRC to form the complete cyclic ETC. This work serves as a foundation for further studies of ACIII-mediated electron transfer in anoxygenic photosynthesis and broadens our understanding of the diversity and molecular evolution of prokaryotic ETCs.
Collapse
Affiliation(s)
- Lu Yu
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China
| | - Zhenzhen Min
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences and Affiliated Hospital, Key Laboratory of Aging and Cancer Biology of Zhejiang Province, Hangzhou Normal University, Hangzhou 311121, China
| | - Menghua Liu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences and Affiliated Hospital, Key Laboratory of Aging and Cancer Biology of Zhejiang Province, Hangzhou Normal University, Hangzhou 311121, China
| | - Yueyong Xin
- Photosynthesis Research Center, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China
| | - Aokun Liu
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China
| | - Jian Kuang
- The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, Center for Bioanalytical Chemistry, Hefei National Laboratory of Physical Science at Microscale, University of Science and Technology of China, Hefei 230026, China
| | - Wenping Wu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences and Affiliated Hospital, Key Laboratory of Aging and Cancer Biology of Zhejiang Province, Hangzhou Normal University, Hangzhou 311121, China
| | - Jingyi Wu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences and Affiliated Hospital, Key Laboratory of Aging and Cancer Biology of Zhejiang Province, Hangzhou Normal University, Hangzhou 311121, China
| | - Huimin He
- Photosynthesis Research Center, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China
| | - Jiyu Xin
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences and Affiliated Hospital, Key Laboratory of Aging and Cancer Biology of Zhejiang Province, Hangzhou Normal University, Hangzhou 311121, China
| | - Robert E Blankenship
- Departments of Biology and Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Changlin Tian
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China; The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, Center for Bioanalytical Chemistry, Hefei National Laboratory of Physical Science at Microscale, University of Science and Technology of China, Hefei 230026, China
| | - Xiaoling Xu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences and Affiliated Hospital, Key Laboratory of Aging and Cancer Biology of Zhejiang Province, Hangzhou Normal University, Hangzhou 311121, China; Photosynthesis Research Center, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China.
| |
Collapse
|
4
|
Calisto F, Todorovic S, Louro RO, Pereira MM. Exploring substrate interaction in respiratory alternative complex III from Rhodothermus marinus. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148983. [PMID: 37127243 DOI: 10.1016/j.bbabio.2023.148983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 04/04/2023] [Accepted: 04/20/2023] [Indexed: 05/03/2023]
Abstract
Rhodothermus marinus is a thermohalophilic organism that has optimized its microaerobic metabolism at 65 °C. We have been exploring its respiratory chain and observed the existence of a quinone:cytochrome c oxidoreductase complex, named Alternative Complex III, structurally different from the bc1 complex. In the present work, we took profit from nanodiscs and liposomes technology to investigate ACIII activity in membrane-mimicking systems. In addition, we studied the interaction of ACIII with menaquinone, its potential electron acceptors (HiPIP and cytochrome c) and the caa3 oxygen reductase.
Collapse
Affiliation(s)
- Filipa Calisto
- University of Lisbon, Faculty of Sciences, Department of Chemistry and Biochemistry and BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8, 1749-016 Lisboa, Portugal
| | - Smilja Todorovic
- Instituto de Tecnologia Química e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157 Oeiras, Portugal
| | - Ricardo O Louro
- Instituto de Tecnologia Química e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157 Oeiras, Portugal
| | - Manuela M Pereira
- University of Lisbon, Faculty of Sciences, Department of Chemistry and Biochemistry and BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8, 1749-016 Lisboa, Portugal.
| |
Collapse
|
5
|
Van Stappen C, Deng Y, Liu Y, Heidari H, Wang JX, Zhou Y, Ledray AP, Lu Y. Designing Artificial Metalloenzymes by Tuning of the Environment beyond the Primary Coordination Sphere. Chem Rev 2022; 122:11974-12045. [PMID: 35816578 DOI: 10.1021/acs.chemrev.2c00106] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Metalloenzymes catalyze a variety of reactions using a limited number of natural amino acids and metallocofactors. Therefore, the environment beyond the primary coordination sphere must play an important role in both conferring and tuning their phenomenal catalytic properties, enabling active sites with otherwise similar primary coordination environments to perform a diverse array of biological functions. However, since the interactions beyond the primary coordination sphere are numerous and weak, it has been difficult to pinpoint structural features responsible for the tuning of activities of native enzymes. Designing artificial metalloenzymes (ArMs) offers an excellent basis to elucidate the roles of these interactions and to further develop practical biological catalysts. In this review, we highlight how the secondary coordination spheres of ArMs influence metal binding and catalysis, with particular focus on the use of native protein scaffolds as templates for the design of ArMs by either rational design aided by computational modeling, directed evolution, or a combination of both approaches. In describing successes in designing heme, nonheme Fe, and Cu metalloenzymes, heteronuclear metalloenzymes containing heme, and those ArMs containing other metal centers (including those with non-native metal ions and metallocofactors), we have summarized insights gained on how careful controls of the interactions in the secondary coordination sphere, including hydrophobic and hydrogen bonding interactions, allow the generation and tuning of these respective systems to approach, rival, and, in a few cases, exceed those of native enzymes. We have also provided an outlook on the remaining challenges in the field and future directions that will allow for a deeper understanding of the secondary coordination sphere a deeper understanding of the secondary coordintion sphere to be gained, and in turn to guide the design of a broader and more efficient variety of ArMs.
Collapse
Affiliation(s)
- Casey Van Stappen
- Department of Chemistry, University of Texas at Austin, 105 East 24th Street, Austin, Texas 78712, United States
| | - Yunling Deng
- Department of Chemistry, University of Texas at Austin, 105 East 24th Street, Austin, Texas 78712, United States
| | - Yiwei Liu
- Department of Chemistry, University of Illinois, Urbana-Champaign, 505 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Hirbod Heidari
- Department of Chemistry, University of Texas at Austin, 105 East 24th Street, Austin, Texas 78712, United States
| | - Jing-Xiang Wang
- Department of Chemistry, University of Texas at Austin, 105 East 24th Street, Austin, Texas 78712, United States
| | - Yu Zhou
- Department of Chemistry, University of Texas at Austin, 105 East 24th Street, Austin, Texas 78712, United States
| | - Aaron P Ledray
- Department of Chemistry, University of Texas at Austin, 105 East 24th Street, Austin, Texas 78712, United States
| | - Yi Lu
- Department of Chemistry, University of Texas at Austin, 105 East 24th Street, Austin, Texas 78712, United States.,Department of Chemistry, University of Illinois, Urbana-Champaign, 505 South Mathews Avenue, Urbana, Illinois 61801, United States
| |
Collapse
|
6
|
McCuskey SR, Chatsirisupachai J, Zeglio E, Parlak O, Panoy P, Herland A, Bazan GC, Nguyen TQ. Current Progress of Interfacing Organic Semiconducting Materials with Bacteria. Chem Rev 2021; 122:4791-4825. [PMID: 34714064 DOI: 10.1021/acs.chemrev.1c00487] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Microbial bioelectronics require interfacing microorganisms with electrodes. The resulting abiotic/biotic platforms provide the basis of a range of technologies, including energy conversion and diagnostic assays. Organic semiconductors (OSCs) provide a unique strategy to modulate the interfaces between microbial systems and external electrodes, thereby improving the performance of these incipient technologies. In this review, we explore recent progress in the field on how OSCs, and related materials capable of charge transport, are being used within the context of microbial systems, and more specifically bacteria. We begin by examining the electrochemical communication modes in bacteria and the biological basis for charge transport. Different types of synthetic organic materials that have been designed and synthesized for interfacing and interrogating bacteria are discussed next, followed by the most commonly used characterization techniques for evaluating transport in microbial, synthetic, and hybrid systems. A range of applications is subsequently examined, including biological sensors and energy conversion systems. The review concludes by summarizing what has been accomplished so far and suggests future design approaches for OSC bioelectronics materials and technologies that hybridize characteristic properties of microbial and OSC systems.
Collapse
Affiliation(s)
- Samantha R McCuskey
- Department of Chemistry, National University of Singapore, Singapore 119077, Singapore
| | - Jirat Chatsirisupachai
- Center for Polymers and Organic Solids & Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States.,Department of Materials Science and Engineering, School of Molecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology, Wangchan, Rayong 21210, Thailand
| | - Erica Zeglio
- Division of Micro and Nanosystems, School of Electrical Engineering and Computer Science, KTH Royal Institute of Technology, Stockholm 17177, Sweden
| | - Onur Parlak
- Dermatology and Venereology Division, Department of Medicine(Solna), Karolinska Institute, Stockholm 17177, Sweden.,AIMES Center of Integrated Medical and Engineering Sciences, Department of Neuroscience, Karolinska Institute, Stockholm 17177, Sweden
| | - Patchareepond Panoy
- Center for Polymers and Organic Solids & Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States.,Department of Materials Science and Engineering, School of Molecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology, Wangchan, Rayong 21210, Thailand
| | - Anna Herland
- Division of Micro and Nanosystems, School of Electrical Engineering and Computer Science, KTH Royal Institute of Technology, Stockholm 17177, Sweden.,AIMES Center of Integrated Medical and Engineering Sciences, Department of Neuroscience, Karolinska Institute, Stockholm 17177, Sweden
| | - Guillermo C Bazan
- Department of Chemistry, National University of Singapore, Singapore 119077, Singapore
| | - Thuc-Quyen Nguyen
- Center for Polymers and Organic Solids & Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
| |
Collapse
|
7
|
Coin G, Latour JM. Nitrene transfers mediated by natural and artificial iron enzymes. J Inorg Biochem 2021; 225:111613. [PMID: 34634542 DOI: 10.1016/j.jinorgbio.2021.111613] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/30/2021] [Accepted: 09/13/2021] [Indexed: 12/19/2022]
Abstract
Amines are ubiquitous in biology and pharmacy. As a consequence, introducing N functionalities in organic molecules is attracting strong continuous interest. The past decade has witnessed the emergence of very efficient and selective catalytic systems achieving this goal thanks to engineered hemoproteins. In this review, we examine how these enzymes have been engineered focusing rather on the rationale behind it than the methodology employed. These studies are put in perspective with respect to in vitro and in vivo nitrene transfer processes performed by cytochromes P450. An emphasis is put on mechanistic aspects which are confronted to current molecular knowledge of these reactions. Forthcoming developments are delineated.
Collapse
Affiliation(s)
- Guillaume Coin
- Univ. Grenoble Alpes, CEA, CNRS, IRIG, DIESE, LCBM, pmb, F-38000 Grenoble, France; Univ. Grenoble Alpes, CNRS UMR 5250, DCM, CIRE, F-38000 Grenoble, France
| | - Jean-Marc Latour
- Univ. Grenoble Alpes, CEA, CNRS, IRIG, DIESE, LCBM, pmb, F-38000 Grenoble, France.
| |
Collapse
|
8
|
Huang H, Zhao D, Yang Z. Theoretical
s
tudy of enantioenriched aminohydroxylation of styrene catalyzed by an engineered hemoprotein. J PHYS ORG CHEM 2021. [DOI: 10.1002/poc.4280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Hong Huang
- School of Chemistry and Chemical Engineering Liaoning Normal University Dalian China
| | - Dong‐Xia Zhao
- School of Chemistry and Chemical Engineering Liaoning Normal University Dalian China
| | - Zhong‐Zhi Yang
- School of Chemistry and Chemical Engineering Liaoning Normal University Dalian China
| |
Collapse
|
9
|
The Monoheme c Subunit of Respiratory Alternative Complex III Is Not Essential for Electron Transfer to Cytochrome aa3 in Flavobacterium johnsoniae. Microbiol Spectr 2021; 9:e0013521. [PMID: 34190594 PMCID: PMC8552683 DOI: 10.1128/spectrum.00135-21] [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] [Indexed: 12/04/2022] Open
Abstract
Bacterial alternative complex III (ACIII) catalyzes menaquinol (MKH2) oxidation, presumably fulfilling the role of cytochromes bc1/b6f in organisms that lack these enzymes. The molecular mechanism of ACIII is unknown and so far the complex has remained inaccessible for genetic modifications. The recently solved cryo-electron microscopy (cryo-EM) structures of ACIII from Flavobacterium johnsoniae, Rhodothermus marinus, and Roseiflexus castenholzii revealed no structural similarity to cytochrome bc1/b6f and there were variations in the heme-containing subunits ActA and ActE. These data implicated intriguing alternative electron transfer paths connecting ACIII with its redox partner, and left the contributions of ActE and the terminal domain of ActA to the catalytic mechanism unclear. Here, we report genetic deletion and complementation of F. johnsoniae actA and actE and the functional implications of such modifications. Deletion of actA led to the loss of activity of cytochrome aa3 (a redox partner of ACIII in this bacterium), which confirmed that ACIII is the sole source of electrons for this complex. Deletion of actE did not impair the activity of cytochrome aa3, revealing that ActE is not required for electron transfer between ACIII and cytochrome aa3. Nevertheless, absence of ActE negatively impacted the cell growth rate, pointing toward another, yet unidentified, function of this subunit. Possible explanations for these observations, including a proposal of a split in electron paths at the ActA/ActE interface, are discussed. The described system for genetic manipulations in F. johnsoniae ACIII offers new tools for studying the molecular mechanism of operation of this enzyme. IMPORTANCE Energy conversion is a fundamental process of all organisms, realized by specialized protein complexes, one of which is alternative complex III (ACIII). ACIII is a functional analogue of well-known mitochondrial complex III, but operates according to a different, still unknown mechanism. To understand how ACIII interacts functionally with its protein partners, we developed a genetic system to mutate the Flavobacterium johnsoniae genes encoding ACIII subunits. Deletion and complementation of heme-containing subunits revealed that ACIII is the sole source of electrons for cytochrome aa3 and that one of the redox-active subunits (ActE) is dispensable for electron transfer between these complexes. This study sheds light on the operation of the supercomplex of ACIII and cytochrome aa3 and suggests a division in the electron path within ACIII. It also shows a way to manipulate protein expression levels for application in other members of the Bacteroidetes phylum.
Collapse
|
10
|
Garcia-Borràs M, Kan SBJ, Lewis RD, Tang A, Jimenez-Osés G, Arnold FH, Houk KN. Origin and Control of Chemoselectivity in Cytochrome c Catalyzed Carbene Transfer into Si-H and N-H bonds. J Am Chem Soc 2021; 143:7114-7123. [PMID: 33909977 DOI: 10.1021/jacs.1c02146] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A cytochrome c heme protein was recently engineered to catalyze the formation of carbon-silicon bonds via carbene insertion into Si-H bonds, a reaction that was not previously known to be catalyzed by a protein. High chemoselectivity toward C-Si bond formation over competing C-N bond formation was achieved, although this trait was not screened for during directed evolution. Using computational and experimental tools, we now establish that activity and chemoselectivity are modulated by conformational dynamics of a protein loop that covers the substrate access to the iron-carbene active species. Mutagenesis of residues computationally predicted to control the loop conformation altered the protein's chemoselectivity from preferred silylation to preferred amination of a substrate containing both N-H and Si-H functionalities. We demonstrate that information on protein structure and conformational dynamics, combined with knowledge of mechanism, leads to understanding of how non-natural and selective chemical transformations can be introduced into the biological world.
Collapse
Affiliation(s)
- Marc Garcia-Borràs
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States.,Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Carrer Maria Aurèlia Capmany 69, 17003 Girona, Spain
| | - S B Jennifer Kan
- Division of Chemistry and Chemical Engineering 210-41, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, United States
| | - Russell D Lewis
- Division of Biology and Bioengineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, United States
| | - Allison Tang
- Division of Chemistry and Chemical Engineering 210-41, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, United States
| | | | - Frances H Arnold
- Division of Biology and Bioengineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, United States.,Division of Chemistry and Chemical Engineering 210-41, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, United States
| | - K N Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| |
Collapse
|
11
|
Calisto F, Sousa FM, Sena FV, Refojo PN, Pereira MM. Mechanisms of Energy Transduction by Charge Translocating Membrane Proteins. Chem Rev 2021; 121:1804-1844. [PMID: 33398986 DOI: 10.1021/acs.chemrev.0c00830] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Life relies on the constant exchange of different forms of energy, i.e., on energy transduction. Therefore, organisms have evolved in a way to be able to harvest the energy made available by external sources (such as light or chemical compounds) and convert these into biological useable energy forms, such as the transmembrane difference of electrochemical potential (Δμ̃). Membrane proteins contribute to the establishment of Δμ̃ by coupling exergonic catalytic reactions to the translocation of charges (electrons/ions) across the membrane. Irrespectively of the energy source and consequent type of reaction, all charge-translocating proteins follow two molecular coupling mechanisms: direct- or indirect-coupling, depending on whether the translocated charge is involved in the driving reaction. In this review, we explore these two coupling mechanisms by thoroughly examining the different types of charge-translocating membrane proteins. For each protein, we analyze the respective reaction thermodynamics, electron transfer/catalytic processes, charge-translocating pathways, and ion/substrate stoichiometries.
Collapse
Affiliation(s)
- Filipa Calisto
- Instituto de Tecnologia Química e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157, Oeiras, Portugal.,BioISI-Biosystems & Integrative Sciences Institute, University of Lisboa, Faculty of Sciences, Campo Grande, 1749-016 Lisboa, Portugal
| | - Filipe M Sousa
- Instituto de Tecnologia Química e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157, Oeiras, Portugal.,BioISI-Biosystems & Integrative Sciences Institute, University of Lisboa, Faculty of Sciences, Campo Grande, 1749-016 Lisboa, Portugal
| | - Filipa V Sena
- Instituto de Tecnologia Química e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157, Oeiras, Portugal.,BioISI-Biosystems & Integrative Sciences Institute, University of Lisboa, Faculty of Sciences, Campo Grande, 1749-016 Lisboa, Portugal
| | - Patricia N Refojo
- Instituto de Tecnologia Química e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157, Oeiras, Portugal
| | - Manuela M Pereira
- Instituto de Tecnologia Química e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157, Oeiras, Portugal.,BioISI-Biosystems & Integrative Sciences Institute, University of Lisboa, Faculty of Sciences, Campo Grande, 1749-016 Lisboa, Portugal
| |
Collapse
|
12
|
González‐Arzola K, Velázquez‐Cruz A, Guerra‐Castellano A, Casado‐Combreras MÁ, Pérez‐Mejías G, Díaz‐Quintana A, Díaz‐Moreno I, De la Rosa MÁ. New moonlighting functions of mitochondrial cytochromecin the cytoplasm and nucleus. FEBS Lett 2019; 593:3101-3119. [DOI: 10.1002/1873-3468.13655] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/13/2019] [Accepted: 10/15/2019] [Indexed: 12/30/2022]
Affiliation(s)
- Katiuska González‐Arzola
- Institute for Chemical Research (IIQ) Scientific Research Centre Isla de la Cartuja (cicCartuja) University of Seville‐CSIC Spain
| | - Alejandro Velázquez‐Cruz
- Institute for Chemical Research (IIQ) Scientific Research Centre Isla de la Cartuja (cicCartuja) University of Seville‐CSIC Spain
| | - Alejandra Guerra‐Castellano
- Institute for Chemical Research (IIQ) Scientific Research Centre Isla de la Cartuja (cicCartuja) University of Seville‐CSIC Spain
| | - Miguel Á. Casado‐Combreras
- Institute for Chemical Research (IIQ) Scientific Research Centre Isla de la Cartuja (cicCartuja) University of Seville‐CSIC Spain
| | - Gonzalo Pérez‐Mejías
- Institute for Chemical Research (IIQ) Scientific Research Centre Isla de la Cartuja (cicCartuja) University of Seville‐CSIC Spain
| | - Antonio Díaz‐Quintana
- Institute for Chemical Research (IIQ) Scientific Research Centre Isla de la Cartuja (cicCartuja) University of Seville‐CSIC Spain
| | - Irene Díaz‐Moreno
- Institute for Chemical Research (IIQ) Scientific Research Centre Isla de la Cartuja (cicCartuja) University of Seville‐CSIC Spain
| | - Miguel Á. De la Rosa
- Institute for Chemical Research (IIQ) Scientific Research Centre Isla de la Cartuja (cicCartuja) University of Seville‐CSIC Spain
| |
Collapse
|
13
|
Leveson-Gower RB, Mayer C, Roelfes G. The importance of catalytic promiscuity for enzyme design and evolution. Nat Rev Chem 2019. [DOI: 10.1038/s41570-019-0143-x] [Citation(s) in RCA: 121] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
14
|
Featherston ER, Rose HR, McBride MJ, Taylor EM, Boal AK, Cotruvo JA. Biochemical and Structural Characterization of XoxG and XoxJ and Their Roles in Lanthanide-Dependent Methanol Dehydrogenase Activity. Chembiochem 2019; 20:2360-2372. [PMID: 31017712 PMCID: PMC6814260 DOI: 10.1002/cbic.201900184] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2019] [Indexed: 12/31/2022]
Abstract
Lanthanide (Ln)-dependent methanol dehydrogenases (MDHs) have recently been shown to be widespread in methylotrophic bacteria. Along with the core MDH protein, XoxF, these systems contain two other proteins, XoxG (a c-type cytochrome) and XoxJ (a periplasmic binding protein of unknown function), about which little is known. In this work, we have biochemically and structurally characterized these proteins from the methyltroph Methylobacterium extorquens AM1. In contrast to results obtained in an artificial assay system, assays of XoxFs metallated with LaIII , CeIII , and NdIII using their physiological electron acceptor, XoxG, display Ln-independent activities, but the Km for XoxG markedly increases from La to Nd. This result suggests that XoxG's redox properties are tuned specifically for lighter Lns in XoxF, an interpretation supported by the unusually low reduction potential of XoxG (+172 mV). The X-ray crystal structure of XoxG provides a structural basis for this reduction potential and insight into the XoxG-XoxF interaction. Finally, the X-ray crystal structure of XoxJ reveals a large hydrophobic cleft and suggests a role in the activation of XoxF. These studies enrich our understanding of the underlying chemical principles that enable the activity of XoxF with multiple lanthanides in vitro and in vivo.
Collapse
Affiliation(s)
- Emily R. Featherston
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA
| | - Hannah R. Rose
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA
| | - Molly J. McBride
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA
| | - Elle M. Taylor
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA
| | - Amie K. Boal
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Joseph A. Cotruvo
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA
| |
Collapse
|
15
|
Chen K, Huang X, Zhang SQ, Zhou AZ, Kan SBJ, Hong X, Arnold FH. Engineered Cytochrome c-Catalyzed Lactone-Carbene B-H Insertion. Synlett 2019; 30:378-382. [PMID: 30930550 PMCID: PMC6436545 DOI: 10.1055/s-0037-1611662] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Previous work has demonstrated that variants of a heme protein, Rhodothermus marinus cytochrome c (Rma cyt c), catalyze abiological carbene boron-hydrogen (B-H) bond insertion with high efficiency and selectivity. Here we investigated this carbon-boron bondforming chemistry with cyclic, lactone-based carbenes. Using directed evolution, we obtained a Rma cyt c variant BOR LAC that shows high selectivity and efficiency for B-H insertion of 5- and 6-membered lactone carbenes (up to 24,500 total turnovers and 97.1:2.9 enantiomeric ratio). The enzyme shows low activity with a 7-membered lactone carbene. Computational studies revealed a highly twisted geometry of the 7membered lactone carbene intermediate relative to 5- and 6-membered ones. Directed evolution of cytochrome c together with computational characterization of key iron-carbene intermediates has allowed us to expand the scope of enzymatic carbene B-H insertion to produce new lactone-based organoborons.
Collapse
Affiliation(s)
- Kai Chen
- Division of Chemistry and Chemical Engineering 210-41, California Institute of Technology, Pasadena, CA 91125, USA
| | - Xiongyi Huang
- Division of Chemistry and Chemical Engineering 210-41, California Institute of Technology, Pasadena, CA 91125, USA
| | - Shuo-Qing Zhang
- Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang 31007, P. R. of China
| | - Andrew Z Zhou
- Division of Chemistry and Chemical Engineering 210-41, California Institute of Technology, Pasadena, CA 91125, USA
| | - S B Jennifer Kan
- Division of Chemistry and Chemical Engineering 210-41, California Institute of Technology, Pasadena, CA 91125, USA
| | - Xin Hong
- Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang 31007, P. R. of China
| | - Frances H Arnold
- Division of Chemistry and Chemical Engineering 210-41, California Institute of Technology, Pasadena, CA 91125, USA
| |
Collapse
|
16
|
Alonso-Cotchico L, Roelfes G. A "Broad Spectrum" Carbene Transferase for Synthesis of Chiral α-Trifluoromethylated Organoborons. ACS CENTRAL SCIENCE 2019; 5:206-208. [PMID: 30834308 PMCID: PMC6396192 DOI: 10.1021/acscentsci.9b00015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
|
17
|
Huang X, Garcia-Borràs M, Miao K, Kan SBJ, Zutshi A, Houk KN, Arnold FH. A Biocatalytic Platform for Synthesis of Chiral α-Trifluoromethylated Organoborons. ACS CENTRAL SCIENCE 2019; 5:270-276. [PMID: 30834315 PMCID: PMC6396380 DOI: 10.1021/acscentsci.8b00679] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Indexed: 05/04/2023]
Abstract
There are few biocatalytic transformations that produce fluorine-containing molecules prevalent in modern pharmaceuticals. To expand the scope of biocatalysis for organofluorine synthesis, we have developed an enzymatic platform for highly enantioselective carbene B-H bond insertion to yield versatile α-trifluoromethylated (α-CF3) organoborons, an important class of organofluorine molecules that contain stereogenic centers bearing both CF3 and boron groups. In contrast to current "carbene transferase" enzymes that use a limited set of simple diazo compounds as carbene precursors, this system based on Rhodothermus marinus cytochrome c (Rma cyt c) can accept a broad range of trifluorodiazo alkanes and deliver versatile chiral α-CF3 organoborons with total turnovers up to 2870 and enantiomeric ratios up to 98.5:1.5. Computational modeling reveals that this broad diazo scope is enabled by an active-site environment that directs the alkyl substituent on the heme CF3-carbene intermediate toward the solvent-exposed face, thereby allowing the protein to accommodate diazo compounds with diverse structural features.
Collapse
Affiliation(s)
- Xiongyi Huang
- Division
of Chemistry and Chemical Engineering, California
Institute of Technology, Pasadena, California 91125, United States
| | - Marc Garcia-Borràs
- Department
of Chemistry and Biochemistry, University
of California, Los Angeles, California 90095, United States
| | - Kun Miao
- Division
of Chemistry and Chemical Engineering, California
Institute of Technology, Pasadena, California 91125, United States
| | - S. B. Jennifer Kan
- Division
of Chemistry and Chemical Engineering, California
Institute of Technology, Pasadena, California 91125, United States
| | - Arjun Zutshi
- Division
of Chemistry and Chemical Engineering, California
Institute of Technology, Pasadena, California 91125, United States
| | - K. N. Houk
- Department
of Chemistry and Biochemistry, University
of California, Los Angeles, California 90095, United States
| | - Frances H. Arnold
- Division
of Chemistry and Chemical Engineering, California
Institute of Technology, Pasadena, California 91125, United States
| |
Collapse
|
18
|
Cho I, Prier CK, Jia Z, Zhang RK, Görbe T, Arnold FH. Enantioselective Aminohydroxylation of Styrenyl Olefins Catalyzed by an Engineered Hemoprotein. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201812968] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Inha Cho
- Division of Chemistry and Chemical Engineering MC 210-41 California Institute of Technology 1200 East California Blvd Pasadena CA 91125 USA
| | - Christopher K. Prier
- Division of Chemistry and Chemical Engineering MC 210-41 California Institute of Technology 1200 East California Blvd Pasadena CA 91125 USA
- Current address: Merck Research Laboratories, Merck & Co. P.O. Box 2000 Rahway NJ 07065 USA
| | - Zhi‐Jun Jia
- Division of Chemistry and Chemical Engineering MC 210-41 California Institute of Technology 1200 East California Blvd Pasadena CA 91125 USA
| | - Ruijie K. Zhang
- Division of Chemistry and Chemical Engineering MC 210-41 California Institute of Technology 1200 East California Blvd Pasadena CA 91125 USA
| | - Tamás Görbe
- Division of Chemistry and Chemical Engineering MC 210-41 California Institute of Technology 1200 East California Blvd Pasadena CA 91125 USA
- Current address: School of Engineering Sciences in Chemistry Biotechnology, and Health KTH Royal Institute of Technology, Science for Life Laboratory 23 Tomtebodavägen 17165 Solna Sweden
| | - Frances H. Arnold
- Division of Chemistry and Chemical Engineering MC 210-41 California Institute of Technology 1200 East California Blvd Pasadena CA 91125 USA
| |
Collapse
|
19
|
Cho I, Prier CK, Jia ZJ, Zhang RK, Görbe T, Arnold FH. Enantioselective Aminohydroxylation of Styrenyl Olefins Catalyzed by an Engineered Hemoprotein. Angew Chem Int Ed Engl 2019; 58:3138-3142. [PMID: 30600873 DOI: 10.1002/anie.201812968] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Indexed: 12/14/2022]
Abstract
Chiral 1,2-amino alcohols are widely represented in biologically active compounds from neurotransmitters to antivirals. While many synthetic methods have been developed for accessing amino alcohols, the direct aminohydroxylation of alkenes to unprotected, enantioenriched amino alcohols remains a challenge. Using directed evolution, we have engineered a hemoprotein biocatalyst based on a thermostable cytochrome c that directly transforms alkenes to amino alcohols with high enantioselectivity (up to 2500 TTN and 90 % ee) under anaerobic conditions with O-pivaloylhydroxylamine as an aminating reagent. The reaction is proposed to proceed via a reactive iron-nitrogen species generated in the enzyme active site, enabling tuning of the catalyst's activity and selectivity by protein engineering.
Collapse
Affiliation(s)
- Inha Cho
- Division of Chemistry and Chemical Engineering MC 210-41, California Institute of Technology, 1200 East California Blvd, Pasadena, CA, 91125, USA
| | - Christopher K Prier
- Division of Chemistry and Chemical Engineering MC 210-41, California Institute of Technology, 1200 East California Blvd, Pasadena, CA, 91125, USA.,Current address: Merck Research Laboratories, Merck & Co., P.O. Box 2000, Rahway, NJ, 07065, USA
| | - Zhi-Jun Jia
- Division of Chemistry and Chemical Engineering MC 210-41, California Institute of Technology, 1200 East California Blvd, Pasadena, CA, 91125, USA
| | - Ruijie K Zhang
- Division of Chemistry and Chemical Engineering MC 210-41, California Institute of Technology, 1200 East California Blvd, Pasadena, CA, 91125, USA
| | - Tamás Görbe
- Division of Chemistry and Chemical Engineering MC 210-41, California Institute of Technology, 1200 East California Blvd, Pasadena, CA, 91125, USA.,Current address: School of Engineering Sciences in Chemistry, Biotechnology, and Health, KTH Royal Institute of Technology, Science for Life Laboratory 23, Tomtebodavägen, 17165, Solna, Sweden
| | - Frances H Arnold
- Division of Chemistry and Chemical Engineering MC 210-41, California Institute of Technology, 1200 East California Blvd, Pasadena, CA, 91125, USA
| |
Collapse
|
20
|
Lewis RD, Garcia-Borràs M, Chalkley MJ, Buller AR, Houk KN, Kan SBJ, Arnold FH. Catalytic iron-carbene intermediate revealed in a cytochrome c carbene transferase. Proc Natl Acad Sci U S A 2018; 115:7308-7313. [PMID: 29946033 PMCID: PMC6048479 DOI: 10.1073/pnas.1807027115] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Recently, heme proteins have been discovered and engineered by directed evolution to catalyze chemical transformations that are biochemically unprecedented. Many of these nonnatural enzyme-catalyzed reactions are assumed to proceed through a catalytic iron porphyrin carbene (IPC) intermediate, although this intermediate has never been observed in a protein. Using crystallographic, spectroscopic, and computational methods, we have captured and studied a catalytic IPC intermediate in the active site of an enzyme derived from thermostable Rhodothermus marinus (Rma) cytochrome c High-resolution crystal structures and computational methods reveal how directed evolution created an active site for carbene transfer in an electron transfer protein and how the laboratory-evolved enzyme achieves perfect carbene transfer stereoselectivity by holding the catalytic IPC in a single orientation. We also discovered that the IPC in Rma cytochrome c has a singlet ground electronic state and that the protein environment uses geometrical constraints and noncovalent interactions to influence different IPC electronic states. This information helps us to understand the impressive reactivity and selectivity of carbene transfer enzymes and offers insights that will guide and inspire future engineering efforts.
Collapse
Affiliation(s)
- Russell D Lewis
- Division of Biology and Bioengineering, California Institute of Technology, Pasadena, CA 91125
| | - Marc Garcia-Borràs
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095
| | - Matthew J Chalkley
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Andrew R Buller
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
| | - K N Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095;
| | - S B Jennifer Kan
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Frances H Arnold
- Division of Biology and Bioengineering, California Institute of Technology, Pasadena, CA 91125;
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
| |
Collapse
|
21
|
Structural basis for energy transduction by respiratory alternative complex III. Nat Commun 2018; 9:1728. [PMID: 29712914 PMCID: PMC5928083 DOI: 10.1038/s41467-018-04141-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 04/02/2018] [Indexed: 01/30/2023] Open
Abstract
Electron transfer in respiratory chains generates the electrochemical potential that serves as energy source for the cell. Prokaryotes can use a wide range of electron donors and acceptors and may have alternative complexes performing the same catalytic reactions as the mitochondrial complexes. This is the case for the alternative complex III (ACIII), a quinol:cytochrome c/HiPIP oxidoreductase. In order to understand the catalytic mechanism of this respiratory enzyme, we determined the structure of ACIII from Rhodothermus marinus at 3.9 Å resolution by single-particle cryo-electron microscopy. ACIII presents a so-far unique structure, for which we establish the arrangement of the cofactors (four iron–sulfur clusters and six c-type hemes) and propose the location of the quinol-binding site and the presence of two putative proton pathways in the membrane. Altogether, this structure provides insights into a mechanism for energy transduction and introduces ACIII as a redox-driven proton pump. Some prokaryotes use alternative respiratory chain complexes, such as the alternative complex III (ACIII), to generate energy. Here authors provide the cryoEM structure of ACIII from Rhodothermus marinus which shows the arrangement of cofactors and provides insights into the mechanism for energy transduction.
Collapse
|
22
|
Jennifer Kan SB, Huang X, Gumulya Y, Chen K, Arnold FH. Genetically programmed chiral organoborane synthesis. Nature 2017; 552:132-136. [PMID: 29186119 PMCID: PMC5819735 DOI: 10.1038/nature24996] [Citation(s) in RCA: 204] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Accepted: 11/02/2017] [Indexed: 12/20/2022]
Abstract
Recent advances in enzyme engineering and design have expanded nature's catalytic repertoire to functions that are new to biology. However, only a subset of these engineered enzymes can function in living systems. Finding enzymatic pathways that form chemical bonds that are not found in biology is particularly difficult in the cellular environment, as this depends on the discovery not only of new enzyme activities, but also of reagents that are both sufficiently reactive for the desired transformation and stable in vivo. Here we report the discovery, evolution and generalization of a fully genetically encoded platform for producing chiral organoboranes in bacteria. Escherichia coli cells harbouring wild-type cytochrome c from Rhodothermus marinus (Rma cyt c) were found to form carbon-boron bonds in the presence of borane-Lewis base complexes, through carbene insertion into boron-hydrogen bonds. Directed evolution of Rma cyt c in the bacterial catalyst provided access to 16 novel chiral organoboranes. The catalyst is suitable for gram-scale biosynthesis, providing up to 15,300 turnovers, a turnover frequency of 6,100 h-1, a 99:1 enantiomeric ratio and 100% chemoselectivity. The enantiopreference of the biocatalyst could also be tuned to provide either enantiomer of the organoborane products. Evolved in the context of whole-cell catalysts, the proteins were more active in the whole-cell system than in purified forms. This study establishes a DNA-encoded and readily engineered bacterial platform for borylation; engineering can be accomplished at a pace that rivals the development of chemical synthetic methods, with the ability to achieve turnovers that are two orders of magnitude (over 400-fold) greater than those of known chiral catalysts for the same class of transformation. This tunable method for manipulating boron in cells could expand the scope of boron chemistry in living systems.
Collapse
Affiliation(s)
| | | | - Yosephine Gumulya
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, MC 210-41, Pasadena, CA 91125, United States
| | - Kai Chen
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, MC 210-41, Pasadena, CA 91125, United States
| | - Frances H. Arnold
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, MC 210-41, Pasadena, CA 91125, United States
| |
Collapse
|
23
|
Design of artificial metalloproteins/metalloenzymes by tuning noncovalent interactions. J Biol Inorg Chem 2017; 23:7-25. [DOI: 10.1007/s00775-017-1506-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2017] [Accepted: 09/20/2017] [Indexed: 12/12/2022]
|
24
|
Bhatnagar A, Bandyopadhyay D. Characterization of cysteine thiol modifications based on protein microenvironments and local secondary structures. Proteins 2017; 86:192-209. [DOI: 10.1002/prot.25424] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 11/09/2017] [Accepted: 11/10/2017] [Indexed: 12/20/2022]
Affiliation(s)
- Akshay Bhatnagar
- Department of Biological Sciences; Birla Institute of Technology and Science, Pilani; Hyderabad India
| | - Debashree Bandyopadhyay
- Department of Biological Sciences; Birla Institute of Technology and Science, Pilani; Hyderabad India
| |
Collapse
|
25
|
Refojo PN, Calisto F, Ribeiro MA, Teixeira M, Pereira MM. The monoheme cytochrome c subunit of Alternative Complex III is a direct electron donor to caa3 oxygen reductase in Rhodothermus marinus. Biol Chem 2017; 398:1037-1044. [DOI: 10.1515/hsz-2016-0323] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 01/23/2017] [Indexed: 11/15/2022]
Abstract
Abstract
Alternative Complex III (ACIII) is an example of the robustness and flexibility of prokaryotic respiratory chains. It performs quinol:cytochrome c oxidoreductase activity, being functionally equivalent to the bc1 complex but structurally unrelated. In this work we further explored ACIII investigating the role of its monoheme cytochrome c subunit (ActE). We expressed and characterized the individually isolated ActE, which allowed us to suggest that ActE is a lipoprotein and to show its function as a direct electron donor to the caa3 oxygen reductase.
Collapse
|
26
|
Kan SBJ, Lewis RD, Chen K, Arnold FH. Directed evolution of cytochrome c for carbon-silicon bond formation: Bringing silicon to life. Science 2017; 354:1048-1051. [PMID: 27885032 DOI: 10.1126/science.aah6219] [Citation(s) in RCA: 384] [Impact Index Per Article: 54.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 10/11/2016] [Indexed: 01/20/2023]
Abstract
Enzymes that catalyze carbon-silicon bond formation are unknown in nature, despite the natural abundance of both elements. Such enzymes would expand the catalytic repertoire of biology, enabling living systems to access chemical space previously only open to synthetic chemistry. We have discovered that heme proteins catalyze the formation of organosilicon compounds under physiological conditions via carbene insertion into silicon-hydrogen bonds. The reaction proceeds both in vitro and in vivo, accommodating a broad range of substrates with high chemo- and enantioselectivity. Using directed evolution, we enhanced the catalytic function of cytochrome c from Rhodothermus marinus to achieve more than 15-fold higher turnover than state-of-the-art synthetic catalysts. This carbon-silicon bond-forming biocatalyst offers an environmentally friendly and highly efficient route to producing enantiopure organosilicon molecules.
Collapse
Affiliation(s)
- S B Jennifer Kan
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Russell D Lewis
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Kai Chen
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Frances H Arnold
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
| |
Collapse
|
27
|
Ducharme J, Auclair K. Enzymes Beat Chemists in the Formation of an Unnatural Bond. Chembiochem 2017; 18:432-434. [PMID: 28026102 DOI: 10.1002/cbic.201600692] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Indexed: 11/12/2022]
Abstract
A fundamental difference? A heme protein known to catalyze electron transfers was engineered into an enzyme that catalyzes the formation of C-Si bonds with >99 % ee. The new enzyme uses diazoesters as carbene donors for the insertion of various silanes into the Si-H bond. This is the first reported organosilicon-producing enzyme.
Collapse
Affiliation(s)
- Julie Ducharme
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, QC, H3A 0B8, Canada
| | - Karine Auclair
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, QC, H3A 0B8, Canada
| |
Collapse
|
28
|
Affiliation(s)
| | - Martin Oestreich
- Institut für Chemie, Technische Universität Berlin, 10623 Berlin, Germany
| |
Collapse
|
29
|
Melo AMP, Teixeira M. Supramolecular organization of bacterial aerobic respiratory chains: From cells and back. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1857:190-7. [PMID: 26546715 DOI: 10.1016/j.bbabio.2015.11.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 10/31/2015] [Accepted: 11/02/2015] [Indexed: 10/22/2022]
Abstract
Aerobic respiratory chains from all life kingdoms are composed by several complexes that have been deeply characterized in their isolated form. These membranous complexes link the oxidation of reducing substrates to the reduction of molecular oxygen, in a process that conserves energy by ion translocation between both sides of the mitochondrial or prokaryotic cytoplasmatic membranes. In recent years there has been increasing evidence that those complexes are organized as supramolecular structures, the so-called supercomplexes and respirasomes, being available for eukaryotes strong data namely obtained by electron microscopy and single particle analysis. A parallel study has been developed for prokaryotes, based on blue native gels and mass spectrometry analysis, showing that in these more simple unicellular organisms such supercomplexes also exist, involving not only typical aerobic-respiration associated complexes, but also anaerobic-linked enzymes. After a short overview of the data on eukaryotic supercomplexes, we will analyse comprehensively the different types of prokaryotic aerobic respiratory supercomplexes that have been thus far suggested, in both bacteria and archaea. This article is part of a Special Issue entitled Organization and dynamics of bioenergetic systems in bacteria, edited by Prof Conrad Mullineaux.
Collapse
Affiliation(s)
- Ana M P Melo
- Instituto Superior de Agronomia, Universidade de Lisboa, Tapada da Ajuda, 1349-017, Lisboa, Portugal.
| | - Miguel Teixeira
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157, Oeiras, Portugal
| |
Collapse
|
30
|
Molinas MF, Benavides L, Castro MA, Murgida DH. Stability, redox parameters and electrocatalytic activity of a cytochrome domain from a new subfamily. Bioelectrochemistry 2015; 105:25-33. [DOI: 10.1016/j.bioelechem.2015.05.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 04/21/2015] [Accepted: 05/03/2015] [Indexed: 11/24/2022]
|
31
|
Dantas JM, Campelo LM, Duke NEC, Salgueiro CA, Pokkuluri PR. The structure of PccH from Geobacter sulfurreducens - a novel low reduction potential monoheme cytochrome essential for accepting electrons from an electrode. FEBS J 2015; 282:2215-31. [PMID: 25786707 DOI: 10.1111/febs.13269] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 02/09/2015] [Accepted: 03/13/2015] [Indexed: 11/27/2022]
Abstract
The structure of cytochrome c (GSU3274) designated as PccH from Geobacter sulfurreducens was determined at a resolution of 2.0 Å. PccH is a small (15 kDa) cytochrome containing one c-type heme, found to be essential for the growth of G. sulfurreducens with respect to accepting electrons from graphite electrodes poised at -300 mV versus standard hydrogen electrode. with fumarate as the terminal electron acceptor. The structure of PccH is unique among the monoheme cytochromes described to date. The structural fold of PccH can be described as forming two lobes with the heme sandwiched in a cleft between the two lobes. In addition, PccH has a low reduction potential of -24 mV at pH 7, which is unusual for monoheme cytochromes. Based on difference in structure, together with sequence phylogenetic analysis, we propose that PccH can be regarded as a first characterized example of a new subclass of class I monoheme cytochromes. The low reduction potential of PccH may enable the protein to be redox active at the typically negative potential ranges encountered by G. sulfurreducens. Because PccH is predicted to be located in the periplasm of this bacterium, it could not be involved in the first step of accepting electrons from the electrode but is very likely involved in the downstream electron transport events in the periplasm.
Collapse
Affiliation(s)
- Joana M Dantas
- UCIBIO - REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| | - Luísa M Campelo
- UCIBIO - REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| | - Norma E C Duke
- Biosciences Division, Argonne National Laboratory, Lemont, IL, USA
| | - Carlos A Salgueiro
- UCIBIO - REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| | - P Raj Pokkuluri
- Biosciences Division, Argonne National Laboratory, Lemont, IL, USA
| |
Collapse
|
32
|
Genomic analysis of Melioribacter roseus, facultatively anaerobic organotrophic bacterium representing a novel deep lineage within Bacteriodetes/Chlorobi group. PLoS One 2013; 8:e53047. [PMID: 23301019 PMCID: PMC3534657 DOI: 10.1371/journal.pone.0053047] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Accepted: 11/23/2012] [Indexed: 11/23/2022] Open
Abstract
Melioribacter roseus is a moderately thermophilic facultatively anaerobic organotrophic bacterium representing a novel deep branch within Bacteriodetes/Chlorobi group. To better understand the metabolic capabilities and possible ecological functions of M. roseus and get insights into the evolutionary history of this bacterial lineage, we sequenced the genome of the type strain P3M-2T. A total of 2838 open reading frames was predicted from its 3.30 Mb genome. The whole proteome analysis supported phylum-level classification of M. roseus since most of the predicted proteins had closest matches in Bacteriodetes, Proteobacteria, Chlorobi, Firmicutes and deeply-branching bacterium Caldithrix abyssi, rather than in one particular phylum. Consistent with the ability of the bacterium to grow on complex carbohydrates, the genome analysis revealed more than one hundred glycoside hydrolases, glycoside transferases, polysaccharide lyases and carbohydrate esterases. The reconstructed central metabolism revealed pathways enabling the fermentation of complex organic substrates, as well as their complete oxidation through aerobic and anaerobic respiration. Genes encoding the photosynthetic and nitrogen-fixation machinery of green sulfur bacteria, as well as key enzymes of autotrophic carbon fixation pathways, were not identified. The M. roseus genome supports its affiliation to a novel phylum Ignavibateriae, representing the first step on the evolutionary pathway from heterotrophic ancestors of Bacteriodetes/Chlorobi group towards anaerobic photoautotrophic Chlorobi.
Collapse
|
33
|
Bonkovsky HL, Guo J, Hou W, Li T, Narang T, Thapar M. Porphyrin and Heme Metabolism and the Porphyrias. Compr Physiol 2013; 3:365-401. [DOI: 10.1002/cphy.c120006] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
34
|
Refojo PN, Teixeira M, Pereira MM. The Alternative complex III: properties and possible mechanisms for electron transfer and energy conservation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1817:1852-9. [PMID: 22609325 DOI: 10.1016/j.bbabio.2012.05.003] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Revised: 05/09/2012] [Accepted: 05/10/2012] [Indexed: 11/17/2022]
Abstract
Alternative complexes III (ACIII) are recently identified membrane-bound enzymes that replace functionally the cytochrome bc(1/)b(6)f complexes. In general, ACIII are composed of four transmembrane proteins and three peripheral subunits that contain iron-sulfur centers and C-type hemes. ACIII are built by a combination of modules present in different enzyme families, namely the complex iron-sulfur molybdenum containing enzymes. In this article a historical perspective on the investigation of ACIII is presented, followed by an overview of the present knowledge on these enzymes. Electron transfer pathways within the protein are discussed taking into account possible different locations (cytoplasmatic or periplasmatic) of the iron-sulfur containing protein and their contribution to energy conservation. In this way several hypotheses for energy conservation modes are raised including linear and bifurcating electron transfer pathways. This article is part of a Special Issue entitled: 17th European Bioenergetics Conference (EBEC 2012).
Collapse
|
35
|
Matsumoto Y, Tosha T, Pisliakov AV, Hino T, Sugimoto H, Nagano S, Sugita Y, Shiro Y. Crystal structure of quinol-dependent nitric oxide reductase from Geobacillus stearothermophilus. Nat Struct Mol Biol 2012; 19:238-45. [PMID: 22266822 DOI: 10.1038/nsmb.2213] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Accepted: 11/22/2011] [Indexed: 11/09/2022]
Abstract
The structure of quinol-dependent nitric oxide reductase (qNOR) from G. stearothermophilus, which catalyzes the reduction of NO to produce the major ozone-depleting gas N(2)O, has been characterized at 2.5 Å resolution. The overall fold of qNOR is similar to that of cytochrome c-dependent NOR (cNOR), and some structural features that are characteristic of cNOR, such as the calcium binding site and hydrophilic cytochrome c domain, are observed in qNOR, even though it harbors no heme c. In contrast to cNOR, structure-based mutagenesis and molecular dynamics simulation studies of qNOR suggest that a water channel from the cytoplasm can serve as a proton transfer pathway for the catalytic reaction. Further structural comparison of qNOR with cNOR and aerobic and microaerobic respiratory oxidases elucidates their evolutionary relationship and possible functional conversions.
Collapse
Affiliation(s)
- Yushi Matsumoto
- Biometal Science Laboratory, RIKEN SPring-8 Center, Sayo, Hyogo, Japan
| | | | | | | | | | | | | | | |
Collapse
|
36
|
Dell'acqua S, Moura I, Moura JJG, Pauleta SR. The electron transfer complex between nitrous oxide reductase and its electron donors. J Biol Inorg Chem 2011; 16:1241-54. [PMID: 21739254 DOI: 10.1007/s00775-011-0812-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Accepted: 06/20/2011] [Indexed: 11/25/2022]
Abstract
Identifying redox partners and the interaction surfaces is crucial for fully understanding electron flow in a respiratory chain. In this study, we focused on the interaction of nitrous oxide reductase (N(2)OR), which catalyzes the final step in bacterial denitrification, with its physiological electron donor, either a c-type cytochrome or a type 1 copper protein. The comparison between the interaction of N(2)OR from three different microorganisms, Pseudomonas nautica, Paracoccus denitrificans, and Achromobacter cycloclastes, with their physiological electron donors was performed through the analysis of the primary sequence alignment, electrostatic surface, and molecular docking simulations, using the bimolecular complex generation with global evaluation and ranking algorithm. The docking results were analyzed taking into account the experimental data, since the interaction is suggested to have either a hydrophobic nature, in the case of P. nautica N(2)OR, or an electrostatic nature, in the case of P. denitrificans N(2)OR and A. cycloclastes N(2)OR. A set of well-conserved residues on the N(2)OR surface were identified as being part of the electron transfer pathway from the redox partner to N(2)OR (Ala495, Asp519, Val524, His566 and Leu568 numbered according to the P. nautica N(2)OR sequence). Moreover, we built a model for Wolinella succinogenes N(2)OR, an enzyme that has an additional c-type-heme-containing domain. The structures of the N(2)OR domain and the c-type-heme-containing domain were modeled and the full-length structure was obtained by molecular docking simulation of these two domains. The orientation of the c-type-heme-containing domain relative to the N(2)OR domain is similar to that found in the other electron transfer complexes.
Collapse
Affiliation(s)
- Simone Dell'acqua
- REQUIMTE/CQFB, Departamento de Química, Universidade Nova de Lisboa, Caparica, Portugal
| | | | | | | |
Collapse
|
37
|
Banci L, Bertini I, Ciofi-Baffoni S, Kozyreva T, Mori M, Wang S. Sco proteins are involved in electron transfer processes. J Biol Inorg Chem 2010; 16:391-403. [DOI: 10.1007/s00775-010-0735-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Accepted: 11/09/2010] [Indexed: 12/01/2022]
|
38
|
Refojo PN, Sousa FL, Teixeira M, Pereira MM. The alternative complex III: a different architecture using known building modules. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:1869-76. [PMID: 20416271 DOI: 10.1016/j.bbabio.2010.04.012] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Revised: 03/05/2010] [Accepted: 04/13/2010] [Indexed: 11/16/2022]
Abstract
Until recently cytochrome bc(1) complexes were the only enzymes known to be able to transfer electrons from reduced quinones to cytochrome c. However, a complex with the same activity and with a unique subunit composition was purified from the membranes of Rhodothermus marinus. This complex, named alternative complex III (ACIII) was then biochemical, spectroscopic and genetically characterized. Later it was observed that the presence of ACIII was not exclusive of R. marinus being the genes coding for ACIII widespread, at least in the Bacteria domain. In this work, a comprehensive description of the current knowledge on ACIII is presented. The relation of ACIII with members of the complex iron-sulfur molybdoenzyme family is investigated by analyzing all the available completely sequenced genomes. It is concluded that ACIII is a new complex composed by a novel combination of modules already identified in other respiratory complexes.
Collapse
Affiliation(s)
- Patrícia N Refojo
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República, EAN, 2780-157 Oeiras, Portugal
| | | | | | | |
Collapse
|
39
|
Structure at 1.0 Å resolution of a high-potential iron–sulfur protein involved in the aerobic respiratory chain of Rhodothermus marinus. J Biol Inorg Chem 2009; 15:303-13. [DOI: 10.1007/s00775-009-0603-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|