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Lee M, Magante K, Gómez-Garzón C, Payne SM, Smith AT. Structural determinants of Vibrio cholerae FeoB nucleotide promiscuity. J Biol Chem 2024; 300:107663. [PMID: 39128725 PMCID: PMC11406355 DOI: 10.1016/j.jbc.2024.107663] [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: 05/31/2024] [Revised: 07/17/2024] [Accepted: 08/04/2024] [Indexed: 08/13/2024] Open
Abstract
Ferrous iron (Fe2+) is required for the growth and virulence of many pathogenic bacteria, including Vibrio cholerae (Vc), the causative agent of the disease cholera. For this bacterium, Feo is the primary system that transports Fe2+ into the cytosol. FeoB, the main component of this system, is regulated by a soluble cytosolic domain termed NFeoB. Recent reanalysis has shown that NFeoBs can be classified as either GTP-specific or NTP-promiscuous, but the structural and mechanistic bases for these differences were not known. To explore this intriguing property of FeoB, we solved the X-ray crystal structures of VcNFeoB in both the apo and the GDP-bound forms. Surprisingly, this promiscuous NTPase displayed a canonical NFeoB G-protein fold like GTP-specific NFeoBs. Using structural bioinformatics, we hypothesized that residues surrounding the nucleobase could be important for both nucleotide affinity and specificity. We then solved the X-ray crystal structures of N150T VcNFeoB in the apo and GDP-bound forms to reveal H-bonding differences surrounding the guanine nucleobase. Interestingly, isothermal titration calorimetry revealed similar binding thermodynamics of the WT and N150T proteins to guanine nucleotides, while the behavior in the presence of adenine nucleotides was dramatically different. AlphaFold models of VcNFeoB in the presence of ADP and ATP showed important conformational changes that contribute to nucleotide specificity among FeoBs. Combined, these results provide a structural framework for understanding FeoB nucleotide promiscuity, which could be an adaptive measure utilized by pathogens to ensure adequate levels of intracellular iron across multiple metabolic landscapes.
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Affiliation(s)
- Mark Lee
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore, Maryland, USA
| | - Kate Magante
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore, Maryland, USA
| | - Camilo Gómez-Garzón
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas, USA
| | - Shelley M Payne
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas, USA; John Ring LaMontagne Center for Infectious Disease, University of Texas at Austin, Austin, Texas, USA
| | - Aaron T Smith
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore, Maryland, USA.
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2
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Chilamakuru NB, Vn AD, G VB, Pallaprolu N, Dande A, Nair D, Pemmadi RV, Reddy Y P, Peraman R. New synergistic benzoquinone scaffolds as inhibitors of mycobacterial cytochrome bc1 complex to treat multi-drug resistant tuberculosis. Eur J Med Chem 2024; 272:116479. [PMID: 38733886 DOI: 10.1016/j.ejmech.2024.116479] [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: 03/18/2024] [Revised: 04/25/2024] [Accepted: 05/04/2024] [Indexed: 05/13/2024]
Abstract
Through a comprehensive molecular docking study, a unique series of naphthoquinones clubbed azetidinone scaffolds was arrived with promising binding affinity to Mycobacterial Cytbc1 complex, a drug target chosen to kill multi-drug resistant Mycobacterium tuberculosis (MDR-Mtb). Five compounds from series-2, 2a, 2c, 2g, 2h, and 2j, showcased significant in vitro anti-tubercular activities against Mtb H37Rv and MDR clinical isolates. Further, synergistic studies of these compounds in combination with INH and RIF revealed a potent bactericidal effect of compound 2a at concentration of 0.39 μg/mL, and remaining (2c, 2g, 2h, and 2j) at 0.78 μg/mL. Exploration into the mechanism study through chemo-stress assay and proteome profiling uncovered the down-regulation of key proteins of electron-transport chain and Cytbc1 inhibition pathway. Metabolomics corroborated these proteome findings, and heightened further understanding of the underlying mechanism. Notably, in vitro and in vivo animal toxicity studies demonstrated minimal toxicity, thus underscoring the potential of these compounds as promising anti-TB agents in combination with RIF and INH. These active compounds adhered to Lipinski's Rule of Five, indicating the suitability of these compounds for drug development. Particular significance of molecules NQ02, 2a, and 2h, which have been patented (Published 202141033473).
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Affiliation(s)
- Naresh Babu Chilamakuru
- Research Scholar, Manipal Academy of Higher Education, Manipal, 576104, Karnataka, India; RERDS-CPR, Raghavendra Institute of Pharmaceutical Education and Research Campus, Ananthapuramu, 515721, Andhra Pradesh, India
| | - Azger Dusthackeer Vn
- ICMR-National Institute for Research in Tuberculosis (NIRT), Chennai, 600031, Tamil Nadu, India
| | - Varadaraj Bhat G
- Department of Pharmaceutical Chemistry, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
| | - Nikhil Pallaprolu
- Department of Pharmaceutical Analysis, National Institute of Pharmaceutical Education and Research (NIPER), Hajipur 844102, Bihar, India
| | - Aishwarya Dande
- Department of Pharmaceutical Analysis, National Institute of Pharmaceutical Education and Research (NIPER), Hajipur 844102, Bihar, India
| | - Dina Nair
- ICMR-National Institute for Research in Tuberculosis (NIRT), Chennai, 600031, Tamil Nadu, India
| | - Raghuveer Varma Pemmadi
- RERDS-CPR, Raghavendra Institute of Pharmaceutical Education and Research Campus, Ananthapuramu, 515721, Andhra Pradesh, India; Department of Pharmaceutical Chemistry, A.K.R.G College of Pharmacy, Nallajerla, Andhra Pradesh 534112.
| | - Padmanabha Reddy Y
- RERDS-CPR, Raghavendra Institute of Pharmaceutical Education and Research Campus, Ananthapuramu, 515721, Andhra Pradesh, India
| | - Ramalingam Peraman
- RERDS-CPR, Raghavendra Institute of Pharmaceutical Education and Research Campus, Ananthapuramu, 515721, Andhra Pradesh, India; Department of Pharmaceutical Analysis, National Institute of Pharmaceutical Education and Research (NIPER), Hajipur 844102, Bihar, India.
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3
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Lee M, Magante K, Gómez-Garzón C, Payne SM, Smith AT. Structural Determinants of Vibrio cholerae FeoB Nucleotide Promiscuity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.22.595361. [PMID: 38826458 PMCID: PMC11142208 DOI: 10.1101/2024.05.22.595361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Ferrous iron (Fe2+) is required for the growth and virulence of many pathogenic bacteria, including Vibrio cholerae (Vc), the causative agent of the disease cholera. For this bacterium, Feo is the primary system that transports Fe2+ into the cytosol. FeoB, the main component of this system, is regulated by a soluble cytosolic domain termed NFeoB. Recent reanalysis has shown that NFeoBs can be classified as either GTP-specific or NTP-promiscuous, but the structural and mechanistic bases for these differences were not known. To explore this intriguing property of FeoB, we solved the X-ray crystal structures of VcNFeoB in both the apo and GDP-bound forms. Surprisingly, this promiscuous NTPase displayed a canonical NFeoB G-protein fold like GTP-specific NFeoBs. Using structural bioinformatics, we hypothesized that residues surrounding the nucleobase could be important for both nucleotide affinity and specificity. We then solved the X-ray crystal structures of N150T VcNFeoB in the apo and GDP-bound forms to reveal H-bonding differences surround the guanine nucleobase. Interestingly, isothermal titration calorimetry revealed similar binding thermodynamics of the WT and N150T proteins to guanine nucleotides, while the behavior in the presence of adenine nucleotides was dramatically different. AlphaFold models of VcNFeoB in the presence of ADP and ATP showed important conformational changes that contribute to nucleotide specificity among FeoBs. Combined, these results provide a structural framework for understanding FeoB nucleotide promiscuity, which could be an adaptive measure utilized by pathogens to ensure adequate levels of intracellular iron across multiple metabolic landscapes.
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Affiliation(s)
- Mark Lee
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore, Maryland, 21250 USA
| | - Kate Magante
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore, Maryland, 21250 USA
| | - Camilo Gómez-Garzón
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas, 78712 USA
| | - Shelley M. Payne
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas, 78712 USA
- John Ring LaMontagne Center for Infectious Disease, University of Texas at Austin, Austin, Texas, 78712 USA
| | - Aaron T. Smith
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore, Maryland, 21250 USA
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Di Trani JM, Gheorghita AA, Turner M, Brzezinski P, Ädelroth P, Vahidi S, Howell PL, Rubinstein JL. Structure of the bc1- cbb3 respiratory supercomplex from Pseudomonas aeruginosa. Proc Natl Acad Sci U S A 2023; 120:e2307093120. [PMID: 37751552 PMCID: PMC10556555 DOI: 10.1073/pnas.2307093120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 08/14/2023] [Indexed: 09/28/2023] Open
Abstract
Energy conversion by electron transport chains occurs through the sequential transfer of electrons between protein complexes and intermediate electron carriers, creating the proton motive force that enables ATP synthesis and membrane transport. These protein complexes can also form higher order assemblies known as respiratory supercomplexes (SCs). The electron transport chain of the opportunistic pathogen Pseudomonas aeruginosa is closely linked with its ability to invade host tissue, tolerate harsh conditions, and resist antibiotics but is poorly characterized. Here, we determine the structure of a P. aeruginosa SC that forms between the quinol:cytochrome c oxidoreductase (cytochrome bc1) and one of the organism's terminal oxidases, cytochrome cbb3, which is found only in some bacteria. Remarkably, the SC structure also includes two intermediate electron carriers: a diheme cytochrome c4 and a single heme cytochrome c5. Together, these proteins allow electron transfer from ubiquinol in cytochrome bc1 to oxygen in cytochrome cbb3. We also present evidence that different isoforms of cytochrome cbb3 can participate in formation of this SC without changing the overall SC architecture. Incorporating these different subunit isoforms into the SC would allow the bacterium to adapt to different environmental conditions. Bioinformatic analysis focusing on structural motifs in the SC suggests that cytochrome bc1-cbb3 SCs also exist in other bacterial pathogens.
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Affiliation(s)
- Justin M. Di Trani
- Molecular Medicine program, The Hospital for Sick Children, Toronto, ONM5G 0A4, Canada
| | - Andreea A. Gheorghita
- Molecular Medicine program, The Hospital for Sick Children, Toronto, ONM5G 0A4, Canada
- Department of Biochemistry, The University of Toronto, Toronto, ONM5S 1A8, Canada
| | - Madison Turner
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ONN1G 2W1, Canada
| | - Peter Brzezinski
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, StockholmSE-106 91, Sweden
| | - Pia Ädelroth
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, StockholmSE-106 91, Sweden
| | - Siavash Vahidi
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ONN1G 2W1, Canada
| | - P. Lynne Howell
- Molecular Medicine program, The Hospital for Sick Children, Toronto, ONM5G 0A4, Canada
- Department of Biochemistry, The University of Toronto, Toronto, ONM5S 1A8, Canada
| | - John L. Rubinstein
- Molecular Medicine program, The Hospital for Sick Children, Toronto, ONM5G 0A4, Canada
- Department of Biochemistry, The University of Toronto, Toronto, ONM5S 1A8, Canada
- Department of Medical Biophysics, The University of Toronto, Toronto, ONM5G 1L7, Canada
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5
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Wang C, Qiao S. Electron transfer mechanism of intracellular carbon-dependent DNRA inside anammox bacteria. WATER RESEARCH 2023; 244:120443. [PMID: 37572465 DOI: 10.1016/j.watres.2023.120443] [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] [Received: 06/10/2023] [Revised: 07/31/2023] [Accepted: 08/01/2023] [Indexed: 08/14/2023]
Abstract
Generally, anaerobic ammonium oxidation (anammox) converts nitrite (NO2-) and ammonium (NH4+) to nitrogen gas (N2) but generates some nitrate (NO3-) (equivalent to 11% of inlet total nitrogen (TN)). Although it reported that anammox bacteria could degrade NO3- via dissimilatory nitrate reduction to ammonium (DNRA) pathway using the intracellular carbon as the electron donor, it is still unclear the specific electron transfer mechanism in this intracellular carbon-dependent DNRA inside anammox bacteria, and whether the sole anammox bacteria could achieve higher TN removal efficiency more than the theoretical maximum of 89%. In this study, transcriptome analysis and metabolic inhibitor experiments demonstrated that NADH generated from the decomposition of the intracellular carbon (glycogen) supplied electrons for the NO3-conversion; the electrons were transferred from NADH to nitrate reductase (Nar) and nitrite reductase forming ammonium (NrfA) from ubiquinone (UQ) and complex III, respectively. Combining the intracellular carbon-dependent DNRA with normal anammox process, an average TN removal efficiency of 95% was achieved by the sole anammox bacteria in a sequencing batch reactor. Fluorescent in situ hybridization (FISH) images and real-time fluorescence quantitative PCR (qPCR) results illustrated anammox bacteria could survive and proliferate in the SBR. Our work improved the understanding of the electron transfer mechanism inside anammox bacteria, and further exploit its potential in nitrogen pollutants removal.
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Affiliation(s)
- Chao Wang
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Sen Qiao
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
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6
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Siletsky SA. Investigation of the Mechanism of Membrane Potential Generation by Heme-Copper Respiratory Oxidases in a Real Time Mode. BIOCHEMISTRY. BIOKHIMIIA 2023; 88:1513-1527. [PMID: 38105021 DOI: 10.1134/s0006297923100085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 08/15/2023] [Accepted: 08/15/2023] [Indexed: 12/19/2023]
Abstract
Heme-copper respiratory oxidases are highly efficient molecular machines. These membrane enzymes catalyze the final step of cellular respiration in eukaryotes and many prokaryotes: the transfer of electrons from cytochromes or quinols to molecular oxygen and oxygen reduction to water. The free energy released in this redox reaction is converted by heme-copper respiratory oxidases into the transmembrane gradient of the electrochemical potential of hydrogen ions H+). Heme-copper respiratory oxidases have a unique mechanism for generating H+, namely, a redox-coupled proton pump. A combination of direct electrometric method for measuring the kinetics of membrane potential generation with the methods of prestationary kinetics and site-directed mutagenesis in the studies of heme-copper oxidases allows to obtain a unique information on the translocation of protons inside the proteins in real time. The review summarizes the data of studies employing time-resolved electrometry to decipher the mechanisms of functioning of these important bioenergetic enzymes.
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Affiliation(s)
- Sergei A Siletsky
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
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7
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Iverson TM, Singh PK, Cecchini G. An evolving view of complex II-noncanonical complexes, megacomplexes, respiration, signaling, and beyond. J Biol Chem 2023; 299:104761. [PMID: 37119852 PMCID: PMC10238741 DOI: 10.1016/j.jbc.2023.104761] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 04/20/2023] [Accepted: 04/22/2023] [Indexed: 05/01/2023] Open
Abstract
Mitochondrial complex II is traditionally studied for its participation in two key respiratory processes: the electron transport chain and the Krebs cycle. There is now a rich body of literature explaining how complex II contributes to respiration. However, more recent research shows that not all of the pathologies associated with altered complex II activity clearly correlate with this respiratory role. Complex II activity has now been shown to be necessary for a range of biological processes peripherally related to respiration, including metabolic control, inflammation, and cell fate. Integration of findings from multiple types of studies suggests that complex II both participates in respiration and controls multiple succinate-dependent signal transduction pathways. Thus, the emerging view is that the true biological function of complex II is well beyond respiration. This review uses a semichronological approach to highlight major paradigm shifts that occurred over time. Special emphasis is given to the more recently identified functions of complex II and its subunits because these findings have infused new directions into an established field.
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Affiliation(s)
- T M Iverson
- Departments of Pharmacology, Vanderbilt University, Nashville, Tennessee, USA; Departments of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA; Center for Structural Biology, Vanderbilt University, Nashville, Tennessee, USA; Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee, USA.
| | - Prashant K Singh
- Departments of Pharmacology, Vanderbilt University, Nashville, Tennessee, USA; Center for Structural Biology, Vanderbilt University, Nashville, Tennessee, USA
| | - Gary Cecchini
- Molecular Biology Division, San Francisco VA Health Care System, San Francisco, California, USA; Department of Biochemistry & Biophysics, University of California, San Francisco, California, USA.
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8
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Wieferig JP, Kühlbrandt W. Analysis of the conformational heterogeneity of the Rieske iron-sulfur protein in complex III 2 by cryo-EM. IUCRJ 2023; 10:27-37. [PMID: 36598500 PMCID: PMC9812224 DOI: 10.1107/s2052252522010570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 11/02/2022] [Indexed: 06/17/2023]
Abstract
Movement of the Rieske domain of the iron-sulfur protein is essential for intramolecular electron transfer within complex III2 (CIII2) of the respiratory chain as it bridges a gap in the cofactor chain towards the electron acceptor cytochrome c. We present cryo-EM structures of CIII2 from Yarrowia lipolytica at resolutions up to 2.0 Å under different conditions, with different redox states of the cofactors of the high-potential chain. All possible permutations of three primary positions were observed, indicating that the two halves of the dimeric complex act independently. Addition of the substrate analogue decylubiquinone to CIII2 with a reduced high-potential chain increased the occupancy of the Qo site. The extent of Rieske domain interactions through hydrogen bonds to the cytochrome b and cytochrome c1 subunits varied depending on the redox state and substrate. In the absence of quinols, the reduced Rieske domain interacted more closely with cytochrome b and cytochrome c1 than in the oxidized state. Upon addition of the inhibitor antimycin A, the heterogeneity of the cd1-helix and ef-loop increased, which may be indicative of a long-range effect on the Rieske domain.
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Affiliation(s)
- Jan-Philip Wieferig
- Department of Structural Biology, Max Planck Institute of Biophysics, Max-von-Laue-Strasse 3, 60438 Frankfurt am Main, Germany
| | - Werner Kühlbrandt
- Department of Structural Biology, Max Planck Institute of Biophysics, Max-von-Laue-Strasse 3, 60438 Frankfurt am Main, Germany
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9
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Marmolejo-Garza A, Medeiros-Furquim T, Rao R, Eggen BJL, Boddeke E, Dolga AM. Transcriptomic and epigenomic landscapes of Alzheimer's disease evidence mitochondrial-related pathways. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2022; 1869:119326. [PMID: 35839870 DOI: 10.1016/j.bbamcr.2022.119326] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 07/06/2022] [Accepted: 07/07/2022] [Indexed: 02/06/2023]
Abstract
Alzheimers disease (AD) is the main cause of dementia and it is defined by cognitive decline coupled to extracellular deposit of amyloid-beta protein and intracellular hyperphosphorylation of tau protein. Historically, efforts to target such hallmarks have failed in numerous clinical trials. In addition to these hallmark-targeted approaches, several clinical trials focus on other AD pathological processes, such as inflammation, mitochondrial dysfunction, and oxidative stress. Mitochondria and mitochondrial-related mechanisms have become an attractive target for disease-modifying strategies, as mitochondrial dysfunction prior to clinical onset has been widely described in AD patients and AD animal models. Mitochondrial function relies on both the nuclear and mitochondrial genome. Findings from omics technologies have shed light on AD pathophysiology at different levels (e.g., epigenome, transcriptome and proteome). Most of these studies have focused on the nuclear-encoded components. The first part of this review provides an updated overview of the mechanisms that regulate mitochondrial gene expression and function. The second part of this review focuses on evidence of mitochondrial dysfunction in AD. We have focused on published findings and datasets that study AD. We analyzed published data and provide examples for mitochondrial-related pathways. These pathways are strikingly dysregulated in AD neurons and glia in sex-, cell- and disease stage-specific manners. Analysis of mitochondrial omics data highlights the involvement of mitochondria in AD, providing a rationale for further disease modeling and drug targeting.
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Affiliation(s)
- Alejandro Marmolejo-Garza
- Department of Molecular Pharmacology, Faculty of Science and Engineering, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, the Netherlands; Department of Biomedical Sciences of Cells & Systems, Section Molecular Neurobiology, Faculty of Medical Sciences, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Tiago Medeiros-Furquim
- Department of Molecular Pharmacology, Faculty of Science and Engineering, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, the Netherlands; Department of Biomedical Sciences of Cells & Systems, Section Molecular Neurobiology, Faculty of Medical Sciences, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Ramya Rao
- Department of Molecular Pharmacology, Faculty of Science and Engineering, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, the Netherlands
| | - Bart J L Eggen
- Department of Biomedical Sciences of Cells & Systems, Section Molecular Neurobiology, Faculty of Medical Sciences, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Erik Boddeke
- Department of Biomedical Sciences of Cells & Systems, Section Molecular Neurobiology, Faculty of Medical Sciences, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands; Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen N, Denmark.
| | - Amalia M Dolga
- Department of Molecular Pharmacology, Faculty of Science and Engineering, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, the Netherlands.
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Spring S, Rohde M, Bunk B, Spröer C, Will SE, Neumann-Schaal M. New insights into the energy metabolism and taxonomy of Deferribacteres revealed by the characterization of a new isolate from a hypersaline microbial mat. Environ Microbiol 2022; 24:2543-2575. [PMID: 35415868 DOI: 10.1111/1462-2920.15999] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 04/04/2022] [Indexed: 12/13/2022]
Abstract
Strain L21-Ace-BEST , isolated from a lithifying cyanobacterial mat, could be assigned to a novel species and genus within the Deferribacteres. It is an important model organism for the study of anaerobic acetate degradation under hypersaline conditions. The metabolism of strain L21-Ace-BEST was characterized by biochemical studies, comparative genome analyses, and the evaluation of gene expression patterns. The central metabolic pathway is the citric acid cycle, which is mainly controlled by the enzyme succinyl-CoA:acetate-CoA transferase. The potential use of a reversed oxidative citric acid cycle to fix CO2 has been revealed through genome analysis. However, no autotrophic growth was detected in this strain, whereas sulfide and H2 can be used mixotrophically. Preferred electron acceptors for the anaerobic oxidation of acetate are nitrate, fumarate and DMSO, while oxygen can be utilized only under microoxic conditions. Aerotolerant growth by fermentation was observed at higher oxygen concentrations. The redox cycling of sulfur/sulfide enables the generation of reducing power for the assimilation of acetate during growth and could prevent the over-reduction of cells in stationary phase. Extracellular electron transfer appears to be an essential component of the respiratory metabolism in this clade of Deferribacteres and may be involved in the reduction of nitrite to ammonium. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Stefan Spring
- Department Microorganisms, Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Manfred Rohde
- Central Facility for Microscopy, Helmholtz Centre for Infection Research, HZI, Braunschweig, Germany
| | - Boyke Bunk
- Department Bioinformatics, Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Cathrin Spröer
- Department Bioinformatics, Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Sabine Eva Will
- Research Group Metabolomics, Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Meina Neumann-Schaal
- Research Group Metabolomics, Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
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11
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Vasilev C, Swainsbury DJK, Cartron ML, Martin EC, Kumar S, Hobbs JK, Johnson MP, Hitchcock A, Hunter CN. FRET measurement of cytochrome bc 1 and reaction centre complex proximity in live Rhodobacter sphaeroides cells. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2022; 1863:148508. [PMID: 34793767 DOI: 10.1016/j.bbabio.2021.148508] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 10/27/2021] [Accepted: 11/09/2021] [Indexed: 11/30/2022]
Abstract
In the model purple phototrophic bacterium Rhodobacter (Rba.) sphaeroides, solar energy is converted via coupled electron and proton transfer reactions within the intracytoplasmic membranes (ICMs), infoldings of the cytoplasmic membrane that form spherical 'chromatophore' vesicles. These bacterial 'organelles' are ideal model systems for studying how the organisation of the photosynthetic complexes therein shape membrane architecture. In Rba. sphaeroides, light-harvesting 2 (LH2) complexes transfer absorbed excitation energy to dimeric reaction centre (RC)-LH1-PufX complexes. The PufX polypeptide creates a channel that allows the lipid soluble electron carrier quinol, produced by RC photochemistry, to diffuse to the cytochrome bc1 complex, where quinols are oxidised to quinones, with the liberated protons used to generate a transmembrane proton gradient and the electrons returned to the RC via cytochrome c2. Proximity between cytochrome bc1 and RC-LH1-PufX minimises quinone/quinol/cytochrome c2 diffusion distances within this protein-crowded membrane, however this distance has not yet been measured. Here, we tag the RC and cytochrome bc1 with yellow or cyan fluorescent proteins (YFP/CFP) and record the lifetimes of YFP/CFP Förster resonance energy transfer (FRET) pairs in whole cells. FRET analysis shows that that these complexes lie on average within 6 nm of each other. Complementary high-resolution atomic force microscopy (AFM) of intact, purified chromatophores verifies the close association of cytochrome bc1 complexes with RC-LH1-PufX dimers. Our results provide a structural basis for the close kinetic coupling between RC-LH1-PufX and cytochrome bc1 observed by spectroscopy, and explain how quinols/quinones and cytochrome c2 shuttle on a millisecond timescale between these complexes, sustaining efficient photosynthetic electron flow.
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Affiliation(s)
- Cvetelin Vasilev
- School of Biosciences, University of Sheffield, Sheffield, S10 2TN, United Kingdom.
| | - David J K Swainsbury
- School of Biosciences, University of Sheffield, Sheffield, S10 2TN, United Kingdom
| | - Michael L Cartron
- School of Biosciences, University of Sheffield, Sheffield, S10 2TN, United Kingdom
| | - Elizabeth C Martin
- School of Biosciences, University of Sheffield, Sheffield, S10 2TN, United Kingdom
| | - Sandip Kumar
- Department of Physics and Astronomy, University of Sheffield, Sheffield, S3 7HR, United Kingdom; Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Jamie K Hobbs
- Department of Physics and Astronomy, University of Sheffield, Sheffield, S3 7HR, United Kingdom
| | - Matthew P Johnson
- School of Biosciences, University of Sheffield, Sheffield, S10 2TN, United Kingdom
| | - Andrew Hitchcock
- School of Biosciences, University of Sheffield, Sheffield, S10 2TN, United Kingdom
| | - C Neil Hunter
- School of Biosciences, University of Sheffield, Sheffield, S10 2TN, United Kingdom
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12
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Andrei A, Di Renzo MA, Öztürk Y, Meisner A, Daum N, Frank F, Rauch J, Daldal F, Andrade SLA, Koch HG. The CopA2-Type P 1B-Type ATPase CcoI Serves as Central Hub for cbb 3-Type Cytochrome Oxidase Biogenesis. Front Microbiol 2021; 12:712465. [PMID: 34589071 PMCID: PMC8475189 DOI: 10.3389/fmicb.2021.712465] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 07/12/2021] [Indexed: 11/13/2022] Open
Abstract
Copper (Cu)-transporting P1B-type ATPases are ubiquitous metal transporters and crucial for maintaining Cu homeostasis in all domains of life. In bacteria, the P1B-type ATPase CopA is required for Cu-detoxification and exports excess Cu(I) in an ATP-dependent reaction from the cytosol into the periplasm. CopA is a member of the CopA1-type ATPase family and has been biochemically and structurally characterized in detail. In contrast, less is known about members of the CopA2-type ATPase family, which are predicted to transport Cu(I) into the periplasm for cuproprotein maturation. One example is CcoI, which is required for the maturation of cbb 3-type cytochrome oxidase (cbb 3-Cox) in different species. Here, we reconstituted purified CcoI of Rhodobacter capsulatus into liposomes and determined Cu transport using solid-supported membrane electrophysiology. The data demonstrate ATP-dependent Cu(I) translocation by CcoI, while no transport is observed in the presence of a non-hydrolysable ATP analog. CcoI contains two cytosolically exposed N-terminal metal binding sites (N-MBSs), which are both important, but not essential for Cu delivery to cbb 3-Cox. CcoI and cbb 3-Cox activity assays in the presence of different Cu concentrations suggest that the glutaredoxin-like N-MBS1 is primarily involved in regulating the ATPase activity of CcoI, while the CopZ-like N-MBS2 is involved in Cu(I) acquisition. The interaction of CcoI with periplasmic Cu chaperones was analyzed by genetically fusing CcoI to the chaperone SenC. The CcoI-SenC fusion protein was fully functional in vivo and sufficient to provide Cu for cbb 3-Cox maturation. In summary, our data demonstrate that CcoI provides the link between the cytosolic and periplasmic Cu chaperone networks during cbb 3-Cox assembly.
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Affiliation(s)
- Andreea Andrei
- Institut für Biochemie und Molekularbiologie, ZBMZ, Faculty of Medicine, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany.,Faculty of Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Maria Agostina Di Renzo
- Institute for Biochemistry, Faculty of Chemistry and Pharmacy, Albert-Ludwigs-University Freiburg, Freiburg, Germany.,Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, Freiburg, Germany.,Faculty of Chemistry and Pharmacy, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Yavuz Öztürk
- Institut für Biochemie und Molekularbiologie, ZBMZ, Faculty of Medicine, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Alexandra Meisner
- Institut für Biochemie und Molekularbiologie, ZBMZ, Faculty of Medicine, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Noel Daum
- Institut für Biochemie und Molekularbiologie, ZBMZ, Faculty of Medicine, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Fabian Frank
- Institute for Biochemistry, Faculty of Chemistry and Pharmacy, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Juna Rauch
- Institut für Biochemie und Molekularbiologie, ZBMZ, Faculty of Medicine, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Fevzi Daldal
- Department of Biology, University of Pennsylvania, Philadelphia, PA, United States
| | - Susana L A Andrade
- Institute for Biochemistry, Faculty of Chemistry and Pharmacy, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Hans-Georg Koch
- Institut für Biochemie und Molekularbiologie, ZBMZ, Faculty of Medicine, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
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13
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Di Trani JM, Liu Z, Whitesell L, Brzezinski P, Cowen LE, Rubinstein JL. Rieske head domain dynamics and indazole-derivative inhibition of Candida albicans complex III. Structure 2021; 30:129-138.e4. [PMID: 34525326 DOI: 10.1016/j.str.2021.08.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 07/06/2021] [Accepted: 08/17/2021] [Indexed: 11/26/2022]
Abstract
Electron transfer between respiratory complexes drives transmembrane proton translocation, which powers ATP synthesis and membrane transport. The homodimeric respiratory complex III (CIII2) oxidizes ubiquinol to ubiquinone, transferring electrons to cytochrome c and translocating protons through a mechanism known as the Q cycle. The Q cycle involves ubiquinol oxidation and ubiquinone reduction at two different sites within each CIII monomer, as well as movement of the head domain of the Rieske subunit. We determined structures of Candida albicans CIII2 by cryoelectron microscopy (cryo-EM), revealing endogenous ubiquinone and visualizing the continuum of Rieske head domain conformations. Analysis of these conformations does not indicate cooperativity in the Rieske head domain position or ligand binding in the two CIIIs of the CIII2 dimer. Cryo-EM with the indazole derivative Inz-5, which inhibits fungal CIII2 and is fungicidal when administered with fungistatic azole drugs, showed that Inz-5 inhibition alters the equilibrium of Rieske head domain positions.
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Affiliation(s)
- Justin M Di Trani
- Molecular Medicine Program, The Hospital for Sick Children, Toronto, ON, Canada
| | - Zhongle Liu
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Luke Whitesell
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Peter Brzezinski
- Department of Biochemistry and Biophysics, Arrhenius Laboratories for Natural Science, Stockholm University, Stockholm, Sweden.
| | - Leah E Cowen
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada.
| | - John L Rubinstein
- Molecular Medicine Program, The Hospital for Sick Children, Toronto, ON, Canada; Department of Biochemistry, University of Toronto, Toronto, ON, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada.
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14
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Brzezinski P, Moe A, Ädelroth P. Structure and Mechanism of Respiratory III-IV Supercomplexes in Bioenergetic Membranes. Chem Rev 2021; 121:9644-9673. [PMID: 34184881 PMCID: PMC8361435 DOI: 10.1021/acs.chemrev.1c00140] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Indexed: 12/12/2022]
Abstract
In the final steps of energy conservation in aerobic organisms, free energy from electron transfer through the respiratory chain is transduced into a proton electrochemical gradient across a membrane. In mitochondria and many bacteria, reduction of the dioxygen electron acceptor is catalyzed by cytochrome c oxidase (complex IV), which receives electrons from cytochrome bc1 (complex III), via membrane-bound or water-soluble cytochrome c. These complexes function independently, but in many organisms they associate to form supercomplexes. Here, we review the structural features and the functional significance of the nonobligate III2IV1/2 Saccharomyces cerevisiae mitochondrial supercomplex as well as the obligate III2IV2 supercomplex from actinobacteria. The analysis is centered around the Q-cycle of complex III, proton uptake by CytcO, as well as mechanistic and structural solutions to the electronic link between complexes III and IV.
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Affiliation(s)
- Peter Brzezinski
- Department of Biochemistry and Biophysics,
The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Agnes Moe
- Department of Biochemistry and Biophysics,
The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Pia Ädelroth
- Department of Biochemistry and Biophysics,
The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
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15
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Garg N, Taylor AJ, Pastorelli F, Flannery SE, Jackson PJ, Johnson MP, Kelly DJ. Genes Linking Copper Trafficking and Homeostasis to the Biogenesis and Activity of the cbb 3-Type Cytochrome c Oxidase in the Enteric Pathogen Campylobacter jejuni. Front Microbiol 2021; 12:683260. [PMID: 34248902 PMCID: PMC8267372 DOI: 10.3389/fmicb.2021.683260] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Accepted: 05/26/2021] [Indexed: 11/13/2022] Open
Abstract
Bacterial C-type haem-copper oxidases in the cbb 3 family are widespread in microaerophiles, which exploit their high oxygen-binding affinity for growth in microoxic niches. In microaerophilic pathogens, C-type oxidases can be essential for infection, yet little is known about their biogenesis compared to model bacteria. Here, we have identified genes involved in cbb 3-oxidase (Cco) assembly and activity in the Gram-negative pathogen Campylobacter jejuni, the commonest cause of human food-borne bacterial gastroenteritis. Several genes of unknown function downstream of the oxidase structural genes ccoNOQP were shown to be essential (cj1483c and cj1486c) or important (cj1484c and cj1485c) for Cco activity; Cj1483 is a CcoH homologue, but Cj1484 (designated CcoZ) has structural similarity to MSMEG_4692, involved in Qcr-oxidase supercomplex formation in Mycobacterium smegmatis. Blue-native polyacrylamide gel electrophoresis of detergent solubilised membranes revealed three major bands, one of which contained CcoZ along with Qcr and oxidase subunits. Deletion of putative copper trafficking genes ccoI (cj1155c) and ccoS (cj1154c) abolished Cco activity, which was partially restored by addition of copper during growth, while inactivation of cj0369c encoding a CcoG homologue led to a partial reduction in Cco activity. Deletion of an operon encoding PCu A C (Cj0909) and Sco (Cj0911) periplasmic copper chaperone homologues reduced Cco activity, which was partially restored in the cj0911 mutant by exogenous copper. Phenotypic analyses of gene deletions in the cj1161c-1166c cluster, encoding several genes involved in intracellular metal homeostasis, showed that inactivation of copA (cj1161c), or copZ (cj1162c) led to both elevated intracellular Cu and reduced Cco activity, effects exacerbated at high external Cu. Our work has therefore identified (i) additional Cco subunits, (ii) a previously uncharacterized set of genes linking copper trafficking and Cco activity, and (iii) connections with Cu homeostasis in this important pathogen.
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Affiliation(s)
- Nitanshu Garg
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, United Kingdom
| | - Aidan J Taylor
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, United Kingdom
| | - Federica Pastorelli
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, United Kingdom
| | - Sarah E Flannery
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, United Kingdom
| | - Phillip J Jackson
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, United Kingdom
| | - Matthew P Johnson
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, United Kingdom
| | - David J Kelly
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, United Kingdom
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16
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Fedotovskaya O, Albertsson I, Nordlund G, Hong S, Gennis RB, Brzezinski P, Ädelroth P. Identification of a cytochrome bc 1-aa 3 supercomplex in Rhodobacter sphaeroides. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2021; 1862:148433. [PMID: 33932366 DOI: 10.1016/j.bbabio.2021.148433] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 04/19/2021] [Accepted: 04/20/2021] [Indexed: 10/21/2022]
Abstract
Respiration is carried out by a series of membrane-bound complexes in the inner mitochondrial membrane or in the cytoplasmic membrane of bacteria. Increasing evidence shows that these complexes organize into larger supercomplexes. In this work, we identified a supercomplex composed of cytochrome (cyt.) bc1 and aa3-type cyt. c oxidase in Rhodobacter sphaeroides. We purified the supercomplex using a His-tag on either of these complexes. The results from activity assays, native and denaturing PAGE, size exclusion chromatography, electron microscopy, optical absorption spectroscopy and kinetic studies on the purified samples support the formation and coupled quinol oxidation:O2 reduction activity of the cyt. bc1-aa3 supercomplex. The potential role of the membrane-anchored cyt. cy as a component in supercomplexes was also investigated.
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Affiliation(s)
- Olga Fedotovskaya
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Ingrid Albertsson
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Gustav Nordlund
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Sangjin Hong
- Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, IL 61801, USA
| | - Robert B Gennis
- Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, IL 61801, USA
| | - Peter Brzezinski
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Pia Ädelroth
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden.
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17
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Steinberg R, Koch HG. The largely unexplored biology of small proteins in pro- and eukaryotes. FEBS J 2021; 288:7002-7024. [PMID: 33780127 DOI: 10.1111/febs.15845] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 03/11/2021] [Accepted: 03/26/2021] [Indexed: 12/29/2022]
Abstract
The large abundance of small open reading frames (smORFs) in prokaryotic and eukaryotic genomes and the plethora of smORF-encoded small proteins became only apparent with the constant advancements in bioinformatic, genomic, proteomic, and biochemical tools. Small proteins are typically defined as proteins of < 50 amino acids in prokaryotes and of less than 100 amino acids in eukaryotes, and their importance for cell physiology and cellular adaptation is only beginning to emerge. In contrast to antimicrobial peptides, which are secreted by prokaryotic and eukaryotic cells for combatting pathogens and competitors, small proteins act within the producing cell mainly by stabilizing protein assemblies and by modifying the activity of larger proteins. Production of small proteins is frequently linked to stress conditions or environmental changes, and therefore, cells seem to use small proteins as intracellular modifiers for adjusting cell metabolism to different intra- and extracellular cues. However, the size of small proteins imposes a major challenge for the cellular machinery required for protein folding and intracellular trafficking and recent data indicate that small proteins can engage distinct trafficking pathways. In the current review, we describe the diversity of small proteins in prokaryotes and eukaryotes, highlight distinct and common features, and illustrate how they are handled by the protein trafficking machineries in prokaryotic and eukaryotic cells. Finally, we also discuss future topics of research on this fascinating but largely unexplored group of proteins.
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Affiliation(s)
- Ruth Steinberg
- Institute for Biochemistry and Molecular Biology, Zentrum für Biochemie und Molekulare Medizin (ZMBZ), Faculty of Medicine, Albert-Ludwigs-Universität Freiburg, Germany
| | - Hans-Georg Koch
- Institute for Biochemistry and Molecular Biology, Zentrum für Biochemie und Molekulare Medizin (ZMBZ), Faculty of Medicine, Albert-Ludwigs-Universität Freiburg, Germany
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