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Meinhold S, Zdanowicz R, Giese C, Glockshuber R. Dimerization of a 5-kDa domain defines the architecture of the 5-MDa gammaproteobacterial pyruvate dehydrogenase complex. SCIENCE ADVANCES 2024; 10:eadj6358. [PMID: 38324697 PMCID: PMC10849603 DOI: 10.1126/sciadv.adj6358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 01/11/2024] [Indexed: 02/09/2024]
Abstract
The Escherichia coli pyruvate dehydrogenase complex (PDHc) is a ~5 MDa assembly of the catalytic subunits pyruvate dehydrogenase (E1), dihydrolipoamide acetyltransferase (E2), and dihydrolipoamide dehydrogenase (E3). The PDHc core is a cubic complex of eight E2 homotrimers. Homodimers of the peripheral subunits E1 and E3 associate with the core by binding to the peripheral subunit binding domain (PSBD) of E2. Previous reports indicated that 12 E1 dimers and 6 E3 dimers bind to the 24-meric E2 core. Using an assembly arrested E2 homotrimer (E23), we show that two of the three PSBDs in the E23 dimerize, that each PSBD dimer cooperatively binds two E1 dimers, and that E3 dimers only bind to the unpaired PSBD in E23. This mechanism is preserved in wild-type PDHc, with an E1 dimer:E2 monomer:E3 dimer stoichiometry of 16:24:8. The conserved PSBD dimer interface indicates that PSBD dimerization is the previously unrecognized architectural determinant of gammaproteobacterial PDHc megacomplexes.
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Affiliation(s)
| | | | - Christoph Giese
- ETH Zürich, Institute of Molecular Biology and Biophysics, Otto-Stern-Weg 5, 8093 Zürich, Switzerland
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2
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Szabo E, Nagy B, Czajlik A, Komlodi T, Ozohanics O, Tretter L, Ambrus A. Mitochondrial Alpha-Keto Acid Dehydrogenase Complexes: Recent Developments on Structure and Function in Health and Disease. Subcell Biochem 2024; 104:295-381. [PMID: 38963492 DOI: 10.1007/978-3-031-58843-3_13] [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] [Indexed: 07/05/2024]
Abstract
The present work delves into the enigmatic world of mitochondrial alpha-keto acid dehydrogenase complexes discussing their metabolic significance, enzymatic operation, moonlighting activities, and pathological relevance with links to underlying structural features. This ubiquitous family of related but diverse multienzyme complexes is involved in carbohydrate metabolism (pyruvate dehydrogenase complex), the citric acid cycle (α-ketoglutarate dehydrogenase complex), and amino acid catabolism (branched-chain α-keto acid dehydrogenase complex, α-ketoadipate dehydrogenase complex); the complexes all function at strategic points and also participate in regulation in these metabolic pathways. These systems are among the largest multienzyme complexes with at times more than 100 protein chains and weights ranging up to ~10 million Daltons. Our chapter offers a wealth of up-to-date information on these multienzyme complexes for a comprehensive understanding of their significance in health and disease.
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Affiliation(s)
- Eszter Szabo
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Balint Nagy
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Andras Czajlik
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Timea Komlodi
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Oliver Ozohanics
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Laszlo Tretter
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Attila Ambrus
- Department of Biochemistry, Semmelweis University, Budapest, Hungary.
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3
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Kilian M, Bischofs IB. Co-evolution at protein-protein interfaces guides inference of stoichiometry of oligomeric protein complexes by de novo structure prediction. Mol Microbiol 2023; 120:763-782. [PMID: 37777474 DOI: 10.1111/mmi.15169] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 09/10/2023] [Accepted: 09/11/2023] [Indexed: 10/02/2023]
Abstract
The quaternary structure with specific stoichiometry is pivotal to the specific function of protein complexes. However, determining the structure of many protein complexes experimentally remains a major bottleneck. Structural bioinformatics approaches, such as the deep learning algorithm Alphafold2-multimer (AF2-multimer), leverage the co-evolution of amino acids and sequence-structure relationships for accurate de novo structure and contact prediction. Pseudo-likelihood maximization direct coupling analysis (plmDCA) has been used to detect co-evolving residue pairs by statistical modeling. Here, we provide evidence that combining both methods can be used for de novo prediction of the quaternary structure and stoichiometry of a protein complex. We achieve this by augmenting the existing AF2-multimer confidence metrics with an interpretable score to identify the complex with an optimal fraction of native contacts of co-evolving residue pairs at intermolecular interfaces. We use this strategy to predict the quaternary structure and non-trivial stoichiometries of Bacillus subtilis spore germination protein complexes with unknown structures. Co-evolution at intermolecular interfaces may therefore synergize with AI-based de novo quaternary structure prediction of structurally uncharacterized bacterial protein complexes.
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Affiliation(s)
- Max Kilian
- Max-Planck-Institute for Terrestrial Microbiology, Marburg, Germany
- BioQuant Center for Quantitative Analysis of Molecular and Cellular Biosystems, Heidelberg University, Heidelberg, Germany
- Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg, Germany
| | - Ilka B Bischofs
- Max-Planck-Institute for Terrestrial Microbiology, Marburg, Germany
- BioQuant Center for Quantitative Analysis of Molecular and Cellular Biosystems, Heidelberg University, Heidelberg, Germany
- Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg, Germany
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4
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Schmid D, Li TR, Goldfuss B, Tiefenbacher K. Exploring the Glycosylation Reaction Inside the Resorcin[4]arene Capsule. J Org Chem 2023; 88:14515-14526. [PMID: 37796244 DOI: 10.1021/acs.joc.3c01547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/06/2023]
Abstract
In the past decade, there has been an increased interest in applying supramolecular capsule and cage catalysis to the current challenges in synthetic organic chemistry. In this context, we recently reported the resorcin[4]arene capsule-catalyzed conversion of α-glycosyl halides into β-glycosides with high selectivity. Interestingly, this methodology enabled the formation of a wide range of β-pyranosides as well as β-furanosides, although these two donor classes exhibit different reactivities and usually require different reaction conditions and catalysts. Evidence was provided that a proton wire plays a key role in this reaction by enabling dual activation of the glycosyl donor and acceptor. Here, we describe a detailed investigation of several aspects of this reactivity. Besides a mechanistic study, we elucidated the size limitation, the origin of catalytic turnover, and the electrophile scope of nonglycosylic halides. Moreover, a screening of the sensitivity to changes in the reaction conditions provides guidelines to facilitate reproducibility. Furthermore, we demonstrate the compatibility with environmentally benign solvent alternatives, including the renewable solvent limonene.
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Affiliation(s)
- Dario Schmid
- Department of Chemistry, University of Basel, Mattenstrasse 24a, 4058 Basel, Switzerland
| | - Tian-Ren Li
- Department of Chemistry, University of Basel, Mattenstrasse 24a, 4058 Basel, Switzerland
| | - Bernd Goldfuss
- Institut für Organische Chemie, Universität zu Köln, Greinstrasse 4, 50939 Köln, Germany
| | - Konrad Tiefenbacher
- Department of Chemistry, University of Basel, Mattenstrasse 24a, 4058 Basel, Switzerland
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 24, 4058 Basel, Switzerland
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5
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Abstract
A survey of protein databases indicates that the majority of enzymes exist in oligomeric forms, with about half of those found in the UniProt database being homodimeric. Understanding why many enzymes are in their dimeric form is imperative. Recent developments in experimental and computational techniques have allowed for a deeper comprehension of the cooperative interactions between the subunits of dimeric enzymes. This review aims to succinctly summarize these recent advancements by providing an overview of experimental and theoretical methods, as well as an understanding of cooperativity in substrate binding and the molecular mechanisms of cooperative catalysis within homodimeric enzymes. Focus is set upon the beneficial effects of dimerization and cooperative catalysis. These advancements not only provide essential case studies and theoretical support for comprehending dimeric enzyme catalysis but also serve as a foundation for designing highly efficient catalysts, such as dimeric organic catalysts. Moreover, these developments have significant implications for drug design, as exemplified by Paxlovid, which was designed for the homodimeric main protease of SARS-CoV-2.
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Affiliation(s)
- Ke-Wei Chen
- Lab of Computional Chemistry and Drug Design, State Key Laboratory of Chemical Oncogenomics, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Tian-Yu Sun
- Shenzhen Bay Laboratory, Shenzhen 518132, China
| | - Yun-Dong Wu
- Lab of Computional Chemistry and Drug Design, State Key Laboratory of Chemical Oncogenomics, Peking University Shenzhen Graduate School, Shenzhen 518055, China
- Shenzhen Bay Laboratory, Shenzhen 518132, China
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6
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Yang L, Wagner T, Mechaly A, Boyko A, Bruch EM, Megrian D, Gubellini F, Alzari PM, Bellinzoni M. High resolution cryo-EM and crystallographic snapshots of the actinobacterial two-in-one 2-oxoglutarate dehydrogenase. Nat Commun 2023; 14:4851. [PMID: 37563123 PMCID: PMC10415282 DOI: 10.1038/s41467-023-40253-6] [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: 02/23/2023] [Accepted: 07/19/2023] [Indexed: 08/12/2023] Open
Abstract
Actinobacteria possess unique ways to regulate the oxoglutarate metabolic node. Contrary to most organisms in which three enzymes compose the 2-oxoglutarate dehydrogenase complex (ODH), actinobacteria rely on a two-in-one protein (OdhA) in which both the oxidative decarboxylation and succinyl transferase steps are carried out by the same polypeptide. Here we describe high-resolution cryo-EM and crystallographic snapshots of representative enzymes from Mycobacterium smegmatis and Corynebacterium glutamicum, showing that OdhA is an 800-kDa homohexamer that assembles into a three-blade propeller shape. The obligate trimeric and dimeric states of the acyltransferase and dehydrogenase domains, respectively, are critical for maintaining the overall assembly, where both domains interact via subtle readjustments of their interfaces. Complexes obtained with substrate analogues, reaction products and allosteric regulators illustrate how these domains operate. Furthermore, we provide additional insights into the phosphorylation-dependent regulation of this enzymatic machinery by the signalling protein OdhI.
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Affiliation(s)
- Lu Yang
- Institut Pasteur, Université Paris Cité, CNRS UMR3528, Unité de Microbiologie Structurale, F-75015, Paris, France
- Wuhan Institute of Biological Products Co. Ltd., Wuhan, 430207, PR China
| | - Tristan Wagner
- Institut Pasteur, Université Paris Cité, CNRS UMR3528, Unité de Microbiologie Structurale, F-75015, Paris, France
- Microbial Metabolism Group, Max Planck Institute for Marine Microbiology, Celsiusstraße 1, D-28359, Bremen, Germany
| | - Ariel Mechaly
- Institut Pasteur, Université Paris Cité, Plateforme de Cristallographie, F-75015, Paris, France
| | - Alexandra Boyko
- Institut Pasteur, Université Paris Cité, CNRS UMR3528, Unité de Microbiologie Structurale, F-75015, Paris, France
- BostonGene, Yerevan, Armenia
| | - Eduardo M Bruch
- Institut Pasteur, Université Paris Cité, CNRS UMR3528, Unité de Microbiologie Structurale, F-75015, Paris, France
- Sanofi, In vitro Biology, Integrated Drug Discovery, 350 Water St, Cambridge, MA, 02141, USA
| | - Daniela Megrian
- Institut Pasteur, Université Paris Cité, CNRS UMR3528, Unité de Microbiologie Structurale, F-75015, Paris, France
| | - Francesca Gubellini
- Institut Pasteur, Université Paris Cité, CNRS UMR3528, Unité de Microbiologie Structurale, F-75015, Paris, France
| | - Pedro M Alzari
- Institut Pasteur, Université Paris Cité, CNRS UMR3528, Unité de Microbiologie Structurale, F-75015, Paris, France
| | - Marco Bellinzoni
- Institut Pasteur, Université Paris Cité, CNRS UMR3528, Unité de Microbiologie Structurale, F-75015, Paris, France.
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7
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Li TR, Piccini G, Tiefenbacher K. Supramolecular Capsule-Catalyzed Highly β-Selective Furanosylation Independent of the S N1/S N2 Reaction Pathway. J Am Chem Soc 2023; 145:4294-4303. [PMID: 36751707 DOI: 10.1021/jacs.2c13641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
The resorcin[4]arene capsule was found to catalyze β-selective furanosylation reactions for a variety of different furanosyl donors: α-d- and α-l-arabinosyl-, α-l-fucosyl-, α-d-ribosyl-, α-d-xylosyl-, and even α-d-lyxosyl fluorides. The scope is only limited by the inherently finite volume inside the closed capsular catalyst. The catalyst is readily available on a multi-100 g scale and can be recycled for at least seven rounds without significant loss in activity, yield, and selectivity. The mechanistic investigations indicated that the furanosylation mechanism is shifted toward an SN1 reaction on the mechanistic continuum between the prototypical SN1 and SN2 substitution types, as compared to the pyranosylation reaction inside the same catalyst. This is especially true for the lyxosyl donor, as indicated by the nucleophile reaction order of 0.26, and supported by metadynamics calculations. The mechanistic shift toward SN1 is of high interest as it indicates that this catalyst not only enables β-selective furanosylations and pyranoslyations independently of the substrate configuration but in addition also independently of the operating mechanism. To our knowledge, there is no alternative catalyst available that displays such properties.
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Affiliation(s)
- Tian-Ren Li
- Department of Chemistry, University of Basel, Mattenstrasse 24a, 4058 Basel, Switzerland
- NCCR Molecular Systems Engineering, BPR 1095, Mattenstrasse 24a, 4058 Basel, Switzerland
| | - GiovanniMaria Piccini
- Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 2, 52074 Aachen, Germany
| | - Konrad Tiefenbacher
- Department of Chemistry, University of Basel, Mattenstrasse 24a, 4058 Basel, Switzerland
- NCCR Molecular Systems Engineering, BPR 1095, Mattenstrasse 24a, 4058 Basel, Switzerland
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, 4058 Basel, Switzerland
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8
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Solovjeva ON. New Role of Water in Transketolase Catalysis. Int J Mol Sci 2023; 24:ijms24032068. [PMID: 36768400 PMCID: PMC9917271 DOI: 10.3390/ijms24032068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Revised: 01/13/2023] [Accepted: 01/16/2023] [Indexed: 01/21/2023] Open
Abstract
Transketolase catalyzes the interconversion of keto and aldo sugars. Its coenzyme is thiamine diphosphate. The binding of keto sugar with thiamine diphosphate is possible only after C2 deprotonation of its thiazole ring. It is believed that deprotonation occurs due to the direct transfer of a proton to the amino group of its aminopyrimidine ring. Using mass spectrometry, it is shown that a water molecule is directly involved in the deprotonation process. After the binding of thiamine diphosphate with transketolase and its subsequent cleavage, a thiamine diphosphate molecule is formed with a mass increased by one oxygen molecule. After fragmentation, a thiamine diphosphate molecule is formed with a mass reduced by one and two hydrogen atoms, that is, HO and H2O are split off. Based on these data, it is assumed that after the formation of holotransketolase, water is covalently bound to thiamine diphosphate, and carbanion is formed as a result of its elimination. This may be a common mechanism for other thiamine enzymes. The participation of a water molecule in the catalysis of the one-substrate transketolase reaction and a possible reason for the effect of the acceptor substrate on the affinity of the donor substrate for active sites are also shown.
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Affiliation(s)
- Olga N Solovjeva
- Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119234 Moscow, Russia
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9
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Kanagaraj K, Rebek J, Yu Y. Self-assembled hexameric capsule: A highly β-selective O-glycosylation reaction enabled via proton wire mechanism. GREEN SYNTHESIS AND CATALYSIS 2022. [DOI: 10.1016/j.gresc.2022.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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10
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Prajapati S, Rabe von Pappenheim F, Tittmann K. Frontiers in the enzymology of thiamin diphosphate-dependent enzymes. Curr Opin Struct Biol 2022; 76:102441. [PMID: 35988322 DOI: 10.1016/j.sbi.2022.102441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Revised: 07/07/2022] [Accepted: 07/11/2022] [Indexed: 11/25/2022]
Abstract
Enzymes that use thiamin diphosphate (ThDP), the biologically active derivative of vitamin B1, as a cofactor play important roles in cellular metabolism in all domains of life. The analysis of ThDP enzymes in the past decades have provided a general framework for our understanding of enzyme catalysis of this protein family. In this review, we will discuss recent advances in the field that include the observation of "unusual" reactions and reaction intermediates that highlight the chemical versatility of the thiamin cofactor. Further topics cover the structural basis of cooperativity of ThDP enzymes, novel insights into the mechanism and structure of selected enzymes, and the discovery of "superassemblies" as reported, for example, acetohydroxy acid synthase. Finally, we summarize recent findings in the structural organisation and mode of action of 2-keto acid dehydrogenase multienzyme complexes and discuss future directions of this exciting research field.
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Affiliation(s)
- Sabin Prajapati
- Department of Molecular Enzymology, Göttingen Center of Molecular Biosciences, Georg-August University Göttingen, Julia-Lermontowa-Weg 3, D-37077 Göttingen, Germany; Max-Planck-Institute for Multidisciplinary Sciences, Am Fassberg 11, D-37077 Göttingen, Germany.
| | - Fabian Rabe von Pappenheim
- Department of Molecular Enzymology, Göttingen Center of Molecular Biosciences, Georg-August University Göttingen, Julia-Lermontowa-Weg 3, D-37077 Göttingen, Germany; Max-Planck-Institute for Multidisciplinary Sciences, Am Fassberg 11, D-37077 Göttingen, Germany.
| | - Kai Tittmann
- Department of Molecular Enzymology, Göttingen Center of Molecular Biosciences, Georg-August University Göttingen, Julia-Lermontowa-Weg 3, D-37077 Göttingen, Germany; Max-Planck-Institute for Multidisciplinary Sciences, Am Fassberg 11, D-37077 Göttingen, Germany.
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11
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Gokcan H, Bedoyan JK, Isayev O. Simulations of Pathogenic E1α Variants: Allostery and Impact on Pyruvate Dehydrogenase Complex-E1 Structure and Function. J Chem Inf Model 2022; 62:3463-3475. [PMID: 35797142 DOI: 10.1021/acs.jcim.2c00630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Pyruvate dehydrogenase complex (PDC) deficiency is a major cause of primary lactic acidemia resulting in high morbidity and mortality, with limited therapeutic options. The E1 component of the mitochondrial multienzyme PDC (PDC-E1) is a symmetric dimer of heterodimers (αβ/α'β') encoded by the PDHA1 and PDHB genes, with two symmetric active sites each consisting of highly conserved phosphorylation loops A and B. PDHA1 mutations are responsible for 82-88% of cases. Greater than 85% of E1α residues with disease-causing missense mutations (DMMs) are solvent-inaccessible, with ∼30% among those involved in subunit-subunit interface contact (SSIC). We performed molecular dynamics simulations of wild-type (WT) PDC-E1 and E1 variants with E1α DMMs at R349 and W185 (residues involved in SSIC), to investigate their impact on human PDC-E1 structure. We evaluated the change in E1 structure and dynamics and examined their implications on E1 function with the specific DMMs. We found that the dynamics of phosphorylation Loop A, which is crucial for E1 biological activity, changes with DMMs that are at least about 15 Å away. Because communication is essential for PDC-E1 activity (with alternating active sites), we also investigated the possible communication network within WT PDC-E1 via centrality analysis. We observed that DMMs altered/disrupted the communication network of PDC-E1. Collectively, these results indicate allosteric effect in PDC-E1, with implications for the development of novel small-molecule therapeutics for specific recurrent E1α DMMs such as replacements of R349 responsible for ∼10% of PDC deficiency due to E1α DMMs.
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Affiliation(s)
- Hatice Gokcan
- Department of Chemistry, Mellon College of Science, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Jirair K Bedoyan
- Division of Genetic and Genomic Medicine, UPMC Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania 15224, United States.,Department of Pediatrics, University of Pittsburgh, Pittsburgh, Pennsylvania 15219, United States
| | - Olexandr Isayev
- Department of Chemistry, Mellon College of Science, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
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12
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Ducich NH, Mears JA, Bedoyan JK. Solvent accessibility of E1α and E1β residues with known missense mutations causing pyruvate dehydrogenase complex (PDC) deficiency: Impact on PDC-E1 structure and function. J Inherit Metab Dis 2022; 45:557-570. [PMID: 35038180 PMCID: PMC9297371 DOI: 10.1002/jimd.12477] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2021] [Revised: 01/11/2022] [Accepted: 01/12/2022] [Indexed: 11/08/2022]
Abstract
Pyruvate dehydrogenase complex deficiency is a major cause of primary lactic acidemia resulting in high morbidity and mortality, with limited therapeutic options. PDHA1 mutations are responsible for >82% of cases. The E1 component of PDC is a symmetric dimer of heterodimers (αβ/α'β') encoded by PDHA1 and PDHB. We measured solvent accessibility surface area (SASA), utilized nearest-neighbor analysis, incorporated sequence changes using mutagenesis tool in PyMOL, and performed molecular modeling with SWISS-MODEL, to investigate the impact of residues with disease-causing missense variants (DMVs) on E1 structure and function. We reviewed 166 and 13 genetically resolved cases due to PDHA1 and PDHB, respectively, from variant databases. We expanded on 102 E1α and 13 E1β nonduplicate DMVs. DMVs of E1α Arg112-Arg224 stretch (exons 5-7) and of E1α Arg residues constituted 40% and 39% of cases, respectively, with invariant Arg349 accounting for 22% of arginine replacements. SASA analysis showed that 86% and 84% of residues with nonduplicate DMVs of E1α and E1β, respectively, are solvent inaccessible ("buried"). Furthermore, 30% of E1α buried residues with DMVs are deleterious through perturbation of subunit-subunit interface contact (SSIC), with 73% located in the Arg112-Arg224 stretch. E1α Arg349 represented 74% of buried E1α Arg residues involved in SSIC. Structural perturbations resulting from residue replacements in some matched neighboring pairs of amino acids on different subunits involved in SSIC at 2.9-4.0 Å interatomic distance apart, exhibit similar clinical phenotype. Collectively, this work provides insight for future target-based advanced molecular modeling studies, with implications for development of novel therapeutics for specific recurrent DMVs of E1α.
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Affiliation(s)
- Nicole H. Ducich
- Case Western Reserve University (CWRU) School of Medicine, Cleveland, Ohio, USA
| | - Jason A. Mears
- Department of Pharmacology, CWRU, Cleveland, Ohio, USA
- Center for Mitochondrial Diseases, CWRU, Cleveland, Ohio, USA
| | - Jirair K. Bedoyan
- Division of Genetic and Genomic Medicine, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Pediatrics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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13
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Rindfleisch S, Krull M, Uranga J, Schmidt T, Rabe von Pappenheim F, Kirck LL, Balouri A, Schneider T, Chari A, Kluger R, Bourenkov G, Diederichsen U, Mata RA, Tittmann K. Ground-state destabilization by electrostatic repulsion is not a driving force in orotidine-5′-monophosphate decarboxylase catalysis. Nat Catal 2022. [DOI: 10.1038/s41929-022-00771-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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14
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Papageorgiou AC. Structural Characterization of Multienzyme Assemblies: An Overview. Methods Mol Biol 2022; 2487:51-72. [PMID: 35687229 DOI: 10.1007/978-1-0716-2269-8_4] [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] [Indexed: 06/15/2023]
Abstract
Multienzyme assemblies have attracted significant attention in recent years for use in industrial applications instead of single enzymes. Owing to their ability to catalyze cascade reactions, multienzyme assemblies have become inspirational tools for the in vitro construction of multienzyme molecular machines. The use of such molecular machines could offer several advantages such as fewer side reactions, a high product yield, a fast reaction speed, easy product separation, a tolerable toxic environment, and robust system operability compared to current microbial cell catalytic systems. Besides, they can provide all the benefits found in the use of enzymes, including reusability, catalytic efficiency, and specificity. Similar to single enzymes, multienzyme assemblies could offer economical and environmentally friendly alternatives to conventional catalysts and play a central role as biocatalysts in green chemistry applications. However, detailed characterization of multienzyme assemblies and a full understanding of their mechanistic details are required for their efficient use in industrial biotransformations. Since the determination of the first enzyme structure in 1965, structural information has played a pivotal role in the characterization of enzymes and elucidation of their structure-function relationship. Among the structural biology techniques, X-ray crystallography has provided key mechanistic details into multienzyme assemblies. Here, the structural characterization of multienzyme assemblies is reviewed and several examples are provided.
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15
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Zahn M, König G, Cuong Pham HV, Seroka B, Lazny R, Yang G, Ouerfelli O, Lotowski Z, Rohwerder T. Mechanistic details of the actinobacterial lyase-catalyzed degradation reaction of 2-hydroxyisobutyryl-CoA. J Biol Chem 2021; 298:101522. [PMID: 34952003 PMCID: PMC8760513 DOI: 10.1016/j.jbc.2021.101522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 12/16/2021] [Accepted: 12/19/2021] [Indexed: 11/28/2022] Open
Abstract
Actinobacterial 2-hydroxyacyl-CoA lyase reversibly catalyzes the thiamine diphosphate-dependent cleavage of 2-hydroxyisobutyryl-CoA to formyl-CoA and acetone. This enzyme has great potential for use in synthetic one-carbon assimilation pathways for sustainable production of chemicals, but lacks details of substrate binding and reaction mechanism for biochemical reengineering. We determined crystal structures of the tetrameric enzyme in the closed conformation with bound substrate, covalent postcleavage intermediate, and products, shedding light on active site architecture and substrate interactions. Together with molecular dynamics simulations of the covalent precleavage complex, the complete catalytic cycle is structurally portrayed, revealing a proton transfer from the substrate acyl Cβ hydroxyl to residue E493 that returns it subsequently to the postcleavage Cα-carbanion intermediate. Kinetic parameters obtained for mutants E493A, E493Q, and E493K confirm the catalytic role of E493 in the WT enzyme. However, the 10- and 50-fold reduction in lyase activity in the E493A and E493Q mutants, respectively, compared with WT suggests that water molecules may contribute to proton transfer. The putative catalytic glutamate is located on a short α-helix close to the active site. This structural feature appears to be conserved in related lyases, such as human 2-hydroxyacyl-CoA lyase 2. Interestingly, a unique feature of the actinobacterial 2-hydroxyacyl-CoA lyase is a large C-terminal lid domain that, together with active site residues L127 and I492, restricts substrate size to ≤C5 2-hydroxyacyl residues. These details about the catalytic mechanism and determinants of substrate specificity pave the ground for designing tailored catalysts for acyloin condensations for one-carbon and short-chain substrates in biotechnological applications.
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Affiliation(s)
- Michael Zahn
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth PO1 2DT, United Kingdom.
| | - Gerhard König
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth PO1 2DT, United Kingdom
| | - Huy Viet Cuong Pham
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Barbara Seroka
- Faculty of Chemistry, University of Bialystok, K. Ciolkowskiego 1K, 15-245 Bialystok, Poland
| | - Ryszard Lazny
- Faculty of Chemistry, University of Bialystok, K. Ciolkowskiego 1K, 15-245 Bialystok, Poland
| | - Guangli Yang
- Organic Synthesis Core Facility, Memorial Sloan Kettering Cancer Center (MSKCC), New York, NY 10065, USA
| | - Ouathek Ouerfelli
- Organic Synthesis Core Facility, Memorial Sloan Kettering Cancer Center (MSKCC), New York, NY 10065, USA
| | - Zenon Lotowski
- Faculty of Chemistry, University of Bialystok, K. Ciolkowskiego 1K, 15-245 Bialystok, Poland
| | - Thore Rohwerder
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.
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16
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Cui J, Tcherkez G. Potassium dependency of enzymes in plant primary metabolism. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2021; 166:522-530. [PMID: 34174657 DOI: 10.1016/j.plaphy.2021.06.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 06/10/2021] [Indexed: 06/13/2023]
Abstract
Potassium is a macroelement essential to many aspects of plant life, such as photosynthesis, phloem transport or cellular electrochemistry. Many enzymes in animals or microbes are known to be stimulated or activated by potassium (K+ ions). Several plant enzymes are also strictly K+-dependent, and this can be critical when plants are under K deficiency and thus intracellular K+ concentration is low. Although metabolic effects of low K conditions have been documented, there is presently no review focusing on roles of K+ for enzyme catalysis or activation in plants. In this mini-review, we compile the current knowledge on K+-requirement of plant enzymes and take advantage of structural data to present biochemical roles of K+. This information is instrumental to explain direct effects of low K+ content on metabolism and this is illustrated with recent metabolomics data.
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Affiliation(s)
- Jing Cui
- Research School of Biology, ANU Joint College of Sciences, Australian National University, 2601, Canberra, Australia
| | - Guillaume Tcherkez
- Research School of Biology, ANU Joint College of Sciences, Australian National University, 2601, Canberra, Australia; Institut de Recherche en Horticulture et Semences, INRAe Angers, Université d'Angers, 42 rue Georges Morel, 49070, Beaucouzé, France.
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17
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Nauton L, Hecquet L, Théry V. QM/MM Study of Human Transketolase: Thiamine Diphosphate Activation Mechanism and Complete Catalytic Cycle. J Chem Inf Model 2021; 61:3502-3515. [PMID: 34161071 DOI: 10.1021/acs.jcim.1c00190] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A computational model for human transketolase was proposed, showing that thiamine diphosphate activation was based on His110 in place of His481 reported in yeast transketolase. In addition, a complete catalytic reaction pathway was investigated using d-xylulose-5-phosphate and d-ribose-5-phosphate as substrates, showing at every step a perfect superimposition of our model with high-resolution crystallographic structures 3MOS, 4KXV, and 4KXX. This study shows that H2N4' of the active thiamine diphosphate "V form" no longer has a self-activating role but allows self-stabilization of the cofactor and of the Breslow intermediate. These advances in our knowledge of the human transketolase mechanism offer interesting prospects for the design of new drugs, this enzyme being involved in several diseases, and for a better understanding of the reactions catalyzed by transketolases from other sources.
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Affiliation(s)
- Lionel Nauton
- Université Clermont Auvergne, CNRS, Clermont Auvergne INP, ICCF, F-63000 Clermont-Ferrand, France
| | - Laurence Hecquet
- Université Clermont Auvergne, CNRS, Clermont Auvergne INP, ICCF, F-63000 Clermont-Ferrand, France
| | - Vincent Théry
- Université Clermont Auvergne, CNRS, Clermont Auvergne INP, ICCF, F-63000 Clermont-Ferrand, France
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18
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Cahlík A, Hellerstedt J, Mendieta-Moreno JI, Švec M, Santhini VM, Pascal S, Soler-Polo D, Erlingsson SI, Výborný K, Mutombo P, Marsalek O, Siri O, Jelínek P. Significance Of Nuclear Quantum Effects In Hydrogen Bonded Molecular Chains. ACS NANO 2021; 15:10357-10365. [PMID: 34033457 DOI: 10.1021/acsnano.1c02572] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
In hydrogen-bonded systems, nuclear quantum effects such as zero-point motion and tunneling can significantly affect their material properties through underlying physical and chemical processes. Presently, direct observation of the influence of nuclear quantum effects on the strength of hydrogen bonds with resulting structural and electronic implications remains elusive, leaving opportunities for deeper understanding to harness their fascinating properties. We studied hydrogen-bonded one-dimensional quinonediimine molecular networks which may adopt two isomeric electronic configurations via proton transfer. Herein, we demonstrate that concerted proton transfer promotes a delocalization of π-electrons along the molecular chain, which enhances the cohesive energy between molecular units, increasing the mechanical stability of the chain and giving rise to distinctive electronic in-gap states localized at the ends. These findings demonstrate the identification of a class of isomeric hydrogen-bonded molecular systems where nuclear quantum effects play a dominant role in establishing their chemical and physical properties. This identification is a step toward the control of mechanical and electronic properties of low-dimensional molecular materials via concerted proton tunneling.
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Affiliation(s)
- Aleš Cahlík
- Institute of Physics of the Czech Academy of Sciences, v.v.i., Cukrovarnicka 10, CZ-16200 Prague 6, Czech Republic
- Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, Břehová 78/7, CZ-11519 Prague 1, Czech Republic
- Regional Centre of Advanced Technologies and Materials, Palacký University, Šlechtitelů 27, CZ-78371 Olomouc, Czech Republic
| | - Jack Hellerstedt
- Institute of Physics of the Czech Academy of Sciences, v.v.i., Cukrovarnicka 10, CZ-16200 Prague 6, Czech Republic
| | - Jesús I Mendieta-Moreno
- Institute of Physics of the Czech Academy of Sciences, v.v.i., Cukrovarnicka 10, CZ-16200 Prague 6, Czech Republic
| | - Martin Švec
- Institute of Physics of the Czech Academy of Sciences, v.v.i., Cukrovarnicka 10, CZ-16200 Prague 6, Czech Republic
- Regional Centre of Advanced Technologies and Materials, Palacký University, Šlechtitelů 27, CZ-78371 Olomouc, Czech Republic
| | - Vijai M Santhini
- Institute of Physics of the Czech Academy of Sciences, v.v.i., Cukrovarnicka 10, CZ-16200 Prague 6, Czech Republic
- Regional Centre of Advanced Technologies and Materials, Palacký University, Šlechtitelů 27, CZ-78371 Olomouc, Czech Republic
| | - Simon Pascal
- Aix Marseille Univ, CNRS, CINaM, UMR 7325, Campus de Luminy, F-13288 Marseille Cedex 09 France
| | - Diego Soler-Polo
- Universidad Autónoma de Madrid, Campus Cantoblanco, ES-28049, Madrid, Spain
| | - Sigurdur I Erlingsson
- School of Science and Engineering, Reykjavik University, Menntavegi 1, IS-101 Reykjavik, Iceland
| | - Karel Výborný
- Institute of Physics of the Czech Academy of Sciences, v.v.i., Cukrovarnicka 10, CZ-16200 Prague 6, Czech Republic
| | - Pingo Mutombo
- Institute of Physics of the Czech Academy of Sciences, v.v.i., Cukrovarnicka 10, CZ-16200 Prague 6, Czech Republic
- Department of Petrochemistry and Refining, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Ondrej Marsalek
- Charles University, Faculty of Mathematics and Physics, Ke Karlovu 3, CZ-12116 Prague 2, Czech Republic
| | - Olivier Siri
- Aix Marseille Univ, CNRS, CINaM, UMR 7325, Campus de Luminy, F-13288 Marseille Cedex 09 France
| | - Pavel Jelínek
- Institute of Physics of the Czech Academy of Sciences, v.v.i., Cukrovarnicka 10, CZ-16200 Prague 6, Czech Republic
- Regional Centre of Advanced Technologies and Materials, Palacký University, Šlechtitelů 27, CZ-78371 Olomouc, Czech Republic
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19
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Structural basis for antibiotic action of the B 1 antivitamin 2'-methoxy-thiamine. Nat Chem Biol 2020; 16:1237-1245. [PMID: 32839604 DOI: 10.1038/s41589-020-0628-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 07/17/2020] [Indexed: 02/07/2023]
Abstract
The natural antivitamin 2'-methoxy-thiamine (MTh) is implicated in the suppression of microbial growth. However, its mode of action and enzyme-selective inhibition mechanism have remained elusive. Intriguingly, MTh inhibits some thiamine diphosphate (ThDP) enzymes, while being coenzymatically active in others. Here we report the strong inhibition of Escherichia coli transketolase activity by MTh and unravel its mode of action and the structural basis thereof. The unique 2'-methoxy group of MTh diphosphate (MThDP) clashes with a canonical glutamate required for cofactor activation in ThDP-dependent enzymes. This glutamate is forced into a stable, anticatalytic low-barrier hydrogen bond with a neighboring glutamate, disrupting cofactor activation. Molecular dynamics simulations of transketolases and other ThDP enzymes identify active-site flexibility and the topology of the cofactor-binding locale as key determinants for enzyme-selective inhibition. Human enzymes either retain enzymatic activity with MThDP or preferentially bind authentic ThDP over MThDP, while core bacterial metabolic enzymes are inhibited, demonstrating therapeutic potential.
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20
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The Two-Species Model of transketolase explains donor substrate-binding, inhibition and heat-activation. Sci Rep 2020; 10:4148. [PMID: 32139871 PMCID: PMC7057962 DOI: 10.1038/s41598-020-61175-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 02/22/2020] [Indexed: 11/23/2022] Open
Abstract
We recently characterised a low-activity form of E. coli transketolase, TKlow, which also binds the cofactor thiamine pyrophosphate (TPP) with an affinity up to two-orders of magnitude lower than the previously known high TPP-affinity and high-activity form, TKhigh, in the presence of Mg2+. We observed previously that partial oxidation was responsible for increased TKhigh activity, while low-activity TKlow was unmodified. In the present study, the fluorescence-based cofactor-binding assay was adapted to detect binding of the β-hydroxypyruvate (HPA) donor substrate to wild-type transketolase and a variant, S385Y/D469T/R520Q, that is active towards aromatic aldehydes. Transketolase HPA affinity again revealed the two distinct forms of transketolase at a TKhigh:TKlow ratio that matched those observed previously via TPP binding to each variant. The HPA dissociation constant of TKlow was comparable to the substrate-inhibition dissociation constant, KiHPA, determined previously. We provide evidence that KiHPA is a convolution of binding to the low-activity TKlow-TKlow dimer, and the TKlow subunit of the partially-active TKhigh-TKlow mixed dimer, where HPA binding to the TKlow subunit of the mixed dimer results in inhibition of the active TKhigh subunit. Heat-activation of transketolase was similarly investigated and found to convert the TKlow subunit of the mixed dimer to have TKhigh-like properties, but without oxidation.
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21
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Mendoza F, Medina FE, Jiménez VA, Jaña GA. Catalytic Role of Gln202 in the Carboligation Reaction Mechanism of Yeast AHAS: A QM/MM Study. J Chem Inf Model 2019; 60:915-922. [DOI: 10.1021/acs.jcim.9b00863] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Fernanda Mendoza
- Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello, Autopista Concepción-Talcahuano, 7100 Talcahuano, Chile
| | - Fabiola E. Medina
- Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello, Autopista Concepción-Talcahuano, 7100 Talcahuano, Chile
| | - Verónica A. Jiménez
- Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello, Autopista Concepción-Talcahuano, 7100 Talcahuano, Chile
| | - Gonzalo A. Jaña
- Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello, Autopista Concepción-Talcahuano, 7100 Talcahuano, Chile
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22
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Wilkinson HC, Dalby PA. Novel insights into transketolase activation by cofactor binding identifies two native species subpopulations. Sci Rep 2019; 9:16116. [PMID: 31695144 PMCID: PMC6834573 DOI: 10.1038/s41598-019-52647-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 10/21/2019] [Indexed: 12/02/2022] Open
Abstract
Transketolase (TK) cofactor binding has been studied extensively over many years, yet certain mysteries remain, such as a lack of consensus on the cooperativity of thiamine pyrophosphate (TPP) binding into the two active sites, in the presence and absence of the divalent cation, Mg2+. Using a novel fluorescence-based assay, we determined directly the dissociation constants and cooperativity of TPP binding and provide the first comprehensive study over a broad range of cofactor concentrations. We confirmed the high-affinity dissociation constants and revealed a dependence of both the affinity and cooperativity of binding on [Mg2+], which explained the previous lack of consensus. A second, discrete and previously uncharacterised low-affinity TPP binding-site was also observed, and hence indicated the existence of two forms of TK with high- (TKhigh) and low-affinity (TKlow). The relative proportions of each dimer were independent of the monomer-dimer transition, as probed by analytical ultracentrifugation at various [TK]. Mass spectrometry revealed that chemical oxidation of TKlow led to the formation of TKhigh, which was 22-fold more active than TKlow. Finally, we propose a two-species model of transketolase activation that describes the interconversions between apo-/holo-TKhigh and TKlow, and the potential to significantly improve biocatalytic activity by populating only the most active form.
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Affiliation(s)
- Henry C Wilkinson
- Department of Biochemical Engineering, University College London, London, WC1E 6BT, UK
| | - Paul A Dalby
- Department of Biochemical Engineering, University College London, London, WC1E 6BT, UK.
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23
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Structure optimization and bioactivity evaluation of ThDP analogs targeting cyanobacterial pyruvate dehydrogenase E1. Bioorg Med Chem 2019; 27:115159. [PMID: 31699453 DOI: 10.1016/j.bmc.2019.115159] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 10/02/2019] [Accepted: 10/08/2019] [Indexed: 11/22/2022]
Abstract
Harmful cyanobacteria bloom (HCB) has occurred frequently in recent years and it is urgent to develop novel algicides to deal with this problem. In this paper, a series of novel thiamin diphosphate (ThDP) analogs 5a-5g were designed and synthesized targeting cyanobacterial pyruvate dehydrogenase complex E1 (Cy-PDHc E1). Our results showed that compounds 5a-5g have higher inhibitory activities against Cy-PDHc E1 (IC50 9.56-3.48 µM) and higher inhibitory activities against two model cyanobacteria strains Synechocystis sp PCC6803 (EC50 2.03-1.58 µM) and Microcystis aeruginosa FACHB905 (EC50 1.86-0.95 µM). Especially, compound 5b displayed highest inhibitory activities (IC50 = 3.48 µM) against Cy-PDHc E1 and powerful inhibitory activities against cyanobacteria Synechocystis sp PCC6803 (EC50 = 1.58 µM) and Microcystis aeruginosa FACHB905 (EC50 = 1.04 µM). Moreover, the inhibitory activities of compound 5b were even higher than those of copper sulfate (EC50 = 2.02 and 1.71 µM separately) which has been widely used as algicide against cyanobacteria PCC6803 and FACHB905. The more important was that compound 5b display much higher inhibitory selectivity between Cy-PDHc E1 (Inhibitory rate 97.4%) and porcine PDHc E1 (Inhibitory rate 11.8%) under the same concentration (100 μM). The inhibition kinetic experiment and molecular docking research showed that compound 5b can inhibit Cy-PDHc E1 by occupying the ThDP-binding pocket and then blocking Cy-PDHc E1 bound to ThDP as competitive inhibitor. The imagines of SEM and TEM showed that cellular microstructures were heavily destroyed under compound 5b stress. Our results demonstrated compound 5b could be taken as a potential lead compound targeting Cy-PDHc E1 to obtain environment-friendly algicide for harmful cyanobacterial blooms control.
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24
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Dai S, Funk LM, von Pappenheim FR, Sautner V, Paulikat M, Schröder B, Uranga J, Mata RA, Tittmann K. Low-barrier hydrogen bonds in enzyme cooperativity. Nature 2019; 573:609-613. [PMID: 31534226 DOI: 10.1038/s41586-019-1581-9] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 08/12/2019] [Indexed: 11/09/2022]
Abstract
The underlying molecular mechanisms of cooperativity and allosteric regulation are well understood for many proteins, with haemoglobin and aspartate transcarbamoylase serving as prototypical examples1,2. The binding of effectors typically causes a structural transition of the protein that is propagated through signalling pathways to remote sites and involves marked changes on the tertiary and sometimes even the quaternary level1-5. However, the origin of these signals and the molecular mechanism of long-range signalling at an atomic level remain unclear5-8. The different spatial scales and timescales in signalling pathways render experimental observation challenging; in particular, the positions and movement of mobile protons cannot be visualized by current methods of structural analysis. Here we report the experimental observation of fluctuating low-barrier hydrogen bonds as switching elements in cooperativity pathways of multimeric enzymes. We have observed these low-barrier hydrogen bonds in ultra-high-resolution X-ray crystallographic structures of two multimeric enzymes, and have validated their assignment using computational calculations. Catalytic events at the active sites switch between low-barrier hydrogen bonds and ordinary hydrogen bonds in a circuit that consists of acidic side chains and water molecules, transmitting a signal through the collective repositioning of protons by behaving as an atomistic Newton's cradle. The resulting communication synchronizes catalysis in the oligomer. Our studies provide several lines of evidence and a working model for not only the existence of low-barrier hydrogen bonds in proteins, but also a connection to enzyme cooperativity. This finding suggests new principles of drug and enzyme design, in which sequences of residues can be purposefully included to enable long-range communication and thus the regulation of engineered biomolecules.
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Affiliation(s)
- Shaobo Dai
- Department of Molecular Enzymology, Göttingen Centre for Molecular Biosciences and Albrecht-von-Haller Institute, Georg-August University Göttingen, Göttingen, Germany.,Department of Structural Dynamics, Max-Planck-Institute for Biophysical Chemistry Göttingen, Göttingen, Germany
| | - Lisa-Marie Funk
- Department of Molecular Enzymology, Göttingen Centre for Molecular Biosciences and Albrecht-von-Haller Institute, Georg-August University Göttingen, Göttingen, Germany.,Department of Structural Dynamics, Max-Planck-Institute for Biophysical Chemistry Göttingen, Göttingen, Germany
| | - Fabian Rabe von Pappenheim
- Department of Molecular Enzymology, Göttingen Centre for Molecular Biosciences and Albrecht-von-Haller Institute, Georg-August University Göttingen, Göttingen, Germany.,Department of Structural Dynamics, Max-Planck-Institute for Biophysical Chemistry Göttingen, Göttingen, Germany
| | - Viktor Sautner
- Department of Molecular Enzymology, Göttingen Centre for Molecular Biosciences and Albrecht-von-Haller Institute, Georg-August University Göttingen, Göttingen, Germany.,Department of Structural Dynamics, Max-Planck-Institute for Biophysical Chemistry Göttingen, Göttingen, Germany
| | - Mirko Paulikat
- Institute of Physical Chemistry, Georg-August University Göttingen, Göttingen, Germany
| | - Benjamin Schröder
- Institute of Physical Chemistry, Georg-August University Göttingen, Göttingen, Germany
| | - Jon Uranga
- Institute of Physical Chemistry, Georg-August University Göttingen, Göttingen, Germany
| | - Ricardo A Mata
- Institute of Physical Chemistry, Georg-August University Göttingen, Göttingen, Germany.
| | - Kai Tittmann
- Department of Molecular Enzymology, Göttingen Centre for Molecular Biosciences and Albrecht-von-Haller Institute, Georg-August University Göttingen, Göttingen, Germany. .,Department of Structural Dynamics, Max-Planck-Institute for Biophysical Chemistry Göttingen, Göttingen, Germany.
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25
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Worthy HL, Auhim HS, Jamieson WD, Pope JR, Wall A, Batchelor R, Johnson RL, Watkins DW, Rizkallah P, Castell OK, Jones DD. Positive functional synergy of structurally integrated artificial protein dimers assembled by Click chemistry. Commun Chem 2019. [DOI: 10.1038/s42004-019-0185-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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26
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Mehrabi P, Di Pietrantonio C, Kim TH, Sljoka A, Taverner K, Ing C, Kruglyak N, Pomès R, Pai EF, Prosser RS. Substrate-Based Allosteric Regulation of a Homodimeric Enzyme. J Am Chem Soc 2019; 141:11540-11556. [PMID: 31188575 DOI: 10.1021/jacs.9b03703] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Many enzymes operate through half-of-the sites reactivity wherein a single protomer is catalytically engaged at one time. In the case of the homodimeric enzyme, fluoroacetate dehalogenase, substrate binding triggers closing of a regulatory cap domain in the empty protomer, preventing substrate access to the remaining active site. However, the empty protomer serves a critical role by acquiring more disorder upon substrate binding, thereby entropically favoring the forward reaction. Empty protomer dynamics are also allosterically coupled to the bound protomer, driving conformational exchange at the active site and progress along the reaction coordinate. Here, we show that at high concentrations, a second substrate binds along the substrate-access channel of the occupied protomer, thereby dampening interprotomer dynamics and inhibiting catalysis. While a mutation (K152I) abrogates second site binding and removes inhibitory effects, it also precipitously lowers the maximum catalytic rate, implying a role for the allosteric pocket at low substrate concentrations, where only a single substrate engages the enzyme at one time. We show that this outer pocket first desolvates the substrate, whereupon it is deposited in the active site. Substrate binding to the active site then triggers the empty outer pocket to serve as an interprotomer allosteric conduit, enabling enhanced dynamics and sampling of activation states needed for catalysis. These allosteric networks and the ensuing changes resulting from second substrate binding are delineated using rigidity-based allosteric transmission theory and validated by nuclear magnetic resonance and functional studies. The results illustrate the role of dynamics along allosteric networks in facilitating function.
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Affiliation(s)
- Pedram Mehrabi
- Department of Medical Biophysics , University of Toronto , Toronto , Ontario M5G 1L7 , Canada.,Department for Atomically Resolved Dynamics , Max-Planck-Institute for Structure and Dynamics of Matter , Luruper Chaussee 149 , 22761 Hamburg , Germany.,Campbell Family Institute for Cancer Research, Princess Margaret Cancer Centre , Toronto , Ontario M5G 1L7 , Canada
| | - Christopher Di Pietrantonio
- Department of Chemistry , University of Toronto, UTM , 3359 Mississauga Road North , Mississauga , Ontario L5L 1C6 , Canada
| | - Tae Hun Kim
- Department of Chemistry , University of Toronto, UTM , 3359 Mississauga Road North , Mississauga , Ontario L5L 1C6 , Canada.,Program in Molecular Medicine, Research Institute, The Hospital for Sick Children , Toronto , Ontario M5G 0A4 , Canada
| | - Adnan Sljoka
- Department of Chemistry , University of Toronto, UTM , 3359 Mississauga Road North , Mississauga , Ontario L5L 1C6 , Canada.,CREST, Japan Science and Technology Agency (JST), Department of Informatics, School of Science and Technology , Kwansei Gakuin University , Sanda 669-1337 , Japan.,Center for Advanced Intelligence Project, RIKEN , 1-4-1 Nihombashi, Chuo-ku , Tokyo 103-0027 , Japan
| | - Keith Taverner
- Department of Chemistry , University of Toronto, UTM , 3359 Mississauga Road North , Mississauga , Ontario L5L 1C6 , Canada
| | - Christopher Ing
- Program in Molecular Medicine, Research Institute, The Hospital for Sick Children , Toronto , Ontario M5G 0A4 , Canada.,Department of Biochemistry , University of Toronto , 1 King's College Circle , Toronto , Ontario M5S 1A8 , Canada
| | - Natasha Kruglyak
- Campbell Family Institute for Cancer Research, Princess Margaret Cancer Centre , Toronto , Ontario M5G 1L7 , Canada.,Department of Biochemistry , University of Toronto , 1 King's College Circle , Toronto , Ontario M5S 1A8 , Canada
| | - Régis Pomès
- Program in Molecular Medicine, Research Institute, The Hospital for Sick Children , Toronto , Ontario M5G 0A4 , Canada.,Department of Biochemistry , University of Toronto , 1 King's College Circle , Toronto , Ontario M5S 1A8 , Canada
| | - Emil F Pai
- Department of Medical Biophysics , University of Toronto , Toronto , Ontario M5G 1L7 , Canada.,Campbell Family Institute for Cancer Research, Princess Margaret Cancer Centre , Toronto , Ontario M5G 1L7 , Canada.,Department of Biochemistry , University of Toronto , 1 King's College Circle , Toronto , Ontario M5S 1A8 , Canada
| | - R Scott Prosser
- Department of Medical Biophysics , University of Toronto , Toronto , Ontario M5G 1L7 , Canada.,Department of Chemistry , University of Toronto, UTM , 3359 Mississauga Road North , Mississauga , Ontario L5L 1C6 , Canada.,Department of Biochemistry , University of Toronto , 1 King's College Circle , Toronto , Ontario M5S 1A8 , Canada
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Feng J, He H, Zhou Y, Guo X, Liu H, Cai M, Wang F, Feng L, He H. Design, synthesis and biological evaluation of novel inhibitors against cyanobacterial pyruvate dehydrogenase multienzyme complex E1. Bioorg Med Chem 2019; 27:2413-2420. [DOI: 10.1016/j.bmc.2019.01.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 01/18/2019] [Accepted: 01/21/2019] [Indexed: 01/06/2023]
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Saá JM, Lillo VJ, Mansilla J. Catalysis by Networks of Cooperative Hydrogen Bonds. NONCOVALENT INTERACTIONS IN CATALYSIS 2019. [DOI: 10.1039/9781788016490-00066] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The main paradigm of today's chemistry is sustainability. In pursuing sustainability, we need to learn from chemical processes carried out by Nature and realize that Nature does not use either strong acids, or strong bases or fancy reagents to achieve outstanding chemical processes. Instead, enzyme activity leans on the cooperation of several chemical entities to avoid strong acids or bases or to achieve such an apparently simple goal as transferring a proton from an NuH unit to an E unit (NuH + E → Nu–EH). Hydrogen bond catalysis emerged strongly two decades ago in trying to imitate Nature and avoid metal catalysis. Now to mount another step in pursuing the goal of sustainability, the focus is upon cooperativity between the different players involved in catalysis. This chapter looks at the concept of cooperativity and, more specifically, (a) examines the role of cooperative hydrogen bonded arrays of the general type NuH⋯(NuH)n⋯NuH (i.e. intermolecular cooperativity) to facilitate general acid–base catalysis, not only in the solution phase but also under solvent-free and catalyst-free conditions, and, most important, (b) analyzes the capacity of designer chiral organocatalysts displaying intramolecular networks of cooperative hydrogen bonds (NCHBs) to facilitate enantioselective synthesis by bringing conformational rigidity to the catalyst in addition to simultaneously increasing the acidity of key hydrogen atoms so to achieve better complementarity in the highly polarized transition states.
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Affiliation(s)
- José M. Saá
- Department de Química, Universitat de les Illes Balears Crta. de Valldemossa km 7.5 07122 Palma de Mallorca Illes Balears Spain
| | - Victor J. Lillo
- Department de Química, Universitat de les Illes Balears Crta. de Valldemossa km 7.5 07122 Palma de Mallorca Illes Balears Spain
| | - Javier Mansilla
- Department de Química, Universitat de les Illes Balears Crta. de Valldemossa km 7.5 07122 Palma de Mallorca Illes Balears Spain
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29
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Drakulic S, Rai J, Petersen SV, Golas MM, Sander B. Folding and assembly defects of pyruvate dehydrogenase deficiency-related variants in the E1α subunit of the pyruvate dehydrogenase complex. Cell Mol Life Sci 2018; 75:3009-3026. [PMID: 29445841 PMCID: PMC11105750 DOI: 10.1007/s00018-018-2775-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 01/31/2018] [Accepted: 02/06/2018] [Indexed: 12/18/2022]
Abstract
The pyruvate dehydrogenase complex (PDC) bridges glycolysis and the citric acid cycle. In human, PDC deficiency leads to severe neurodevelopmental delay and progressive neurodegeneration. The majority of cases are caused by variants in the gene encoding the PDC subunit E1α. The molecular effects of the variants, however, remain poorly understood. Using yeast as a eukaryotic model system, we have studied the substitutions A189V, M230V, and R322C in yeast E1α (corresponding to the pathogenic variants A169V, M210V, and R302C in human E1α) and evaluated how substitutions of single amino acid residues within different functional E1α regions affect PDC structure and activity. The E1α A189V substitution located in the heterodimer interface showed a more compact conformation with significant underrepresentation of E1 in PDC and impaired overall PDC activity. The E1α M230V substitution located in the tetramer and heterodimer interface showed a relatively more open conformation and was particularly affected by low thiamin pyrophosphate concentrations. The E1α R322C substitution located in the phosphorylation loop of E1α resulted in PDC lacking E3 subunits and abolished overall functional activity. Furthermore, we show for the E1α variant A189V that variant E1α accumulates in the Hsp60 chaperonin, but can be released upon ATP supplementation. Our studies suggest that pathogenic E1α variants may be associated with structural changes of PDC and impaired folding of E1α.
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Affiliation(s)
- Srdja Drakulic
- Department of Biomedicine, Aarhus University, 8000, Aarhus C, Denmark
| | - Jay Rai
- Centre for Stochastic Geometry and Advanced Bioimaging, Aarhus University, 8000, Aarhus C, Denmark
| | | | - Monika M Golas
- Department of Biomedicine, Aarhus University, 8000, Aarhus C, Denmark.
- Department of Human Genetics, Hannover Medical School, 30625 Hannover, Germany.
| | - Bjoern Sander
- Centre for Stochastic Geometry and Advanced Bioimaging, Aarhus University, 8000, Aarhus C, Denmark.
- Institute of Pathology, Hannover Medical School, 30625 Hannover, Germany.
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Wielgus-Kutrowska B, Grycuk T, Bzowska A. Part-of-the-sites binding and reactivity in the homooligomeric enzymes - facts and artifacts. Arch Biochem Biophys 2018; 642:31-45. [PMID: 29408402 DOI: 10.1016/j.abb.2018.01.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 01/13/2018] [Accepted: 01/17/2018] [Indexed: 01/18/2023]
Abstract
For a number of enzymes composed of several subunits with the same amino acid sequence, it was documented, or suggested, that binding of a ligand, or catalysis, is carried out by a single subunit. This phenomenon may be the result of a pre-existent asymmetry of subunits or a limiting case of the negative cooperativity, and is sometimes called "half-of-the-sites binding (or reactivity)" for dimers and could be called "part-of-the-sites binding (or reactivity)" for higher oligomers. In this article, we discuss molecular mechanisms that may result in "part-of-the-sites binding (and reactivity)", offer possible explanations why it may have a beneficial role in enzyme function, and point to experimental problems in documenting this behaviour. We describe some cases, for which such a mechanism was first reported and later disproved. We also give several examples of enzymes, for which this mechanism seems to be well documented, and profitable. A majority of enzymes identified in this study as half-of-the-sites binding (or reactive) use it in the flip-flop version, in which "half-of-the-sites" refers to a particular moment in time. In general, the various variants of the mechanism seems to be employed often by oligomeric enzymes for allosteric regulation to enhance the efficiency of enzymatic reactions in many key metabolic pathways.
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Affiliation(s)
- Beata Wielgus-Kutrowska
- Division of Biophysics, Institute of Experimental Physics, Department of Physics, University of Warsaw, Pasteura 5, Warsaw, 02-093, Poland.
| | - Tomasz Grycuk
- Division of Biophysics, Institute of Experimental Physics, Department of Physics, University of Warsaw, Pasteura 5, Warsaw, 02-093, Poland
| | - Agnieszka Bzowska
- Division of Biophysics, Institute of Experimental Physics, Department of Physics, University of Warsaw, Pasteura 5, Warsaw, 02-093, Poland.
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31
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Handa S, Dempsey DR, Ramamoorthy D, Cook N, Guida WC, Spradling TJ, White JK, Woodcock HL, Merkler DJ. Mechanistic Studies of 1-Deoxy-D-Xylulose-5-Phosphate Synthase from Deinococcus radiodurans. ACTA ACUST UNITED AC 2018; 4. [PMID: 29552677 PMCID: PMC5851014 DOI: 10.21767/2471-8084.100051] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The non-mevalonate dependent (NMVA) pathway for the biosynthesis of isopentenyl pyrophosphate and dimethylallyl pyrophosphate is the sole source of these terpenoids for the production of isoprenoids in the apicomplexan parasites, in many eubacteria, and in plants. The absence of this pathway in higher organisms has opened a new platform for the development of novel antibiotics and anti-malarials. The enzyme catalyzing the first step of the NMVA pathway is 1-deoxy-D-xylulose-5-phosphate synthase (DXPS). DXPS catalyzes the thiamine pyrophosphate- and Mg (II)-dependent conjugation of pyruvate and D-glyceraldehyde-3-phosphate to form 1-deoxy-D-xylulose-5-phosphate and CO2. The kinetic mechanism of DXPS from Deinococcus radiodurans most consistent with our data is random sequential as shown using a combination of kinetic analysis and product and dead-end inhibition studies. The role of active site amino acids, identified by sequence alignment to other DXPS proteins, was probed by constructing and analyzing the catalytic efficacy of a set of targeted site-directed mutants.
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Affiliation(s)
- Sumit Handa
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Daniel R Dempsey
- Departments of Medicine, Biological Chemistry and Molecular Pharmacology, Harvard Medical School and Brigham and Women's Hospital, Boston, UK
| | | | - Nanci Cook
- Department of Chemistry, University of South Florida, USA
| | - Wayne C Guida
- Department of Chemistry, University of South Florida, USA
| | | | - Justin K White
- Department of Chemistry, University of South Florida, USA
| | - H Lee Woodcock
- Department of Chemistry, University of South Florida, USA
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32
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Wineman-Fisher V, Simkovich R, Huppert D, Trujillo K, Remington SJ, Miller Y. Mutagenic induction of an ultra-fast water-chain proton wire. Phys Chem Chem Phys 2018; 18:23089-95. [PMID: 27492977 DOI: 10.1039/c6cp05071a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Replacement of the hydroxyl group of a hydrophilic sidechain by an H atom in the proton wire of GFP induces formation of a water-chain proton wire. Surprisingly, this "non-native" water chain functions as a proton wire with response times within 10 ps of the wild type protein. This remarkable rate retention is understood as a natural consequence of the well-known Grotthuss mechanism of proton transfer in water.
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Affiliation(s)
- Vered Wineman-Fisher
- Department of Chemistry, Ben-Gurion University of the Negev, P.O. Box 653, Be'er Sheva 84105, Israel. and Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beér-Sheva 84105, Israel
| | - Ron Simkovich
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv 69978, Israel
| | - Dan Huppert
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv 69978, Israel
| | - Kristina Trujillo
- Department of Physics and Institute of Molecular Biology, University of Oregon, Eugene, USA
| | - S James Remington
- Department of Physics and Institute of Molecular Biology, University of Oregon, Eugene, USA
| | - Yifat Miller
- Department of Chemistry, Ben-Gurion University of the Negev, P.O. Box 653, Be'er Sheva 84105, Israel. and Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beér-Sheva 84105, Israel
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Abstract
The family of 2-oxoacid dehydrogenase complexes (2-OADC), typified by the pyruvate dehydrogenase multi-enzyme complex (PDC) as its most prominent member, are massive molecular machines (Mr, 4-10 million) controlling key steps in glucose homeostasis (PDC), citric acid cycle flux (OGDC, 2-oxoglutarate dehydrogenase) and the metabolism of the branched-chain amino acids, leucine, isoleucine and valine (BCOADC, branched-chain 2-OADC). These highly organised mitochondrial arrays, composed of multiple copies of three separate enzymes, have been widely studied as paradigms for the analysis of enzyme cooperativity, substrate channelling, protein-protein interactions and the regulation of activity by phosphorylation . This chapter will highlight recent advances in our understanding of the structure-function relationships, the overall organisation and the transport and assembly of PDC in particular, focussing on both native and recombinant forms of the complex and their individual components or constituent domains. Biophysical approaches, including X-ray crystallography (MX), nuclear magnetic resonance spectroscopy (NMR), cryo-EM imaging, analytical ultracentrifugation (AUC) and small angle X-ray and neutron scattering (SAXS and SANS), have all contributed significant new information on PDC subunit organisation, stoichiometry, regulatory mechanisms and mode of assembly. Moreover, the recognition of specific genetic defects linked to PDC deficiency, in combination with the ability to analyse recombinant PDCs housing both novel naturally-occurring and engineered mutations, have all stimulated renewed interest in these classical metabolic assemblies. In addition, the role played by PDC, and its constituent proteins, in certain disease states will be briefly reviewed, focussing on the development of new and exciting areas of medical and immunological research.
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Affiliation(s)
- Olwyn Byron
- School of Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - John Gordon Lindsay
- Institute of Molecular, Cell and Systems Biology, Davidson Building, College of Medicine, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK.
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Prakash M, Subramanian V. Ab initio and density functional theory (DFT) studies on triflic acid with water and protonated water clusters. J Mol Model 2016; 22:293. [PMID: 27888404 DOI: 10.1007/s00894-016-3158-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Accepted: 11/08/2016] [Indexed: 02/04/2023]
Abstract
The structure, stability and infrared spectral signatures of triflic acid (TA) with water clusters (Wn) and protonated water clusters (TAH+Wn, n = 1 - 6) were computed using DFT and MP2 methods. Our calculations show that a minimum of three water molecules are necessary to stabilize the dissociated zwitterionic form of TA. It can be seen from the results that there is no significant movement of protons in smaller (n = 1 and 2) and linear (n = 1 - 6) types of water clusters. Further, the geometries of TAWn clusters first form a neutral pair (NP) to contact ion pair (CIP), then form a solvent separated ion pair (SSIP) in a water hexamer. These findings reveal that proton transfer may take place through NP to CIP and then CIP to SSIP. The calculated binding energies (BEs) of ion pair clusters is always higher than that of NP clusters (i.e., more stable than the NP). Existing excess proton linear chain clusters transfer a proton to adjacent water molecules via a Grotthuss mechanism, whereas the same isomers in the branched motifs do not conduct protons. Examination of geometrical parameters and infrared frequencies reveals hydronium ion (H3O+ also called Eigen cation) formation in both TAWn and protonated TAWn clusters. The stability of Eigen water clusters is three times higher than that of other non-Eigen water clusters. Our study shows clearly that formation of ion pairs in TAWn and TAH+Wn clusters greatly favors proton transfer to neighboring water molecules and also enhances the stability of these complexes.
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Affiliation(s)
- M Prakash
- Department of Chemistry and Research Institute, SRM University, Kattankulathur, 603203, Tamil Nadu, India
- Chemical Laboratory, CSIR-Central Leather Research Institute, Adyar, Chennai, 600 020, India
| | - V Subramanian
- Chemical Laboratory, CSIR-Central Leather Research Institute, Adyar, Chennai, 600 020, India.
- Academy of Scientific and Innovative Research (AcSIR), CSIR-CLRI Campus, Chennai, 600 020, India.
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Brezovsky J, Babkova P, Degtjarik O, Fortova A, Gora A, Iermak I, Rezacova P, Dvorak P, Smatanova IK, Prokop Z, Chaloupkova R, Damborsky J. Engineering a de Novo Transport Tunnel. ACS Catal 2016. [DOI: 10.1021/acscatal.6b02081] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Jan Brezovsky
- Loschmidt
Laboratories, Department of Experimental Biology and Research Centre
for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Petra Babkova
- Loschmidt
Laboratories, Department of Experimental Biology and Research Centre
for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Oksana Degtjarik
- Faculty
of Science, University of South Bohemia in Ceske Budejovice, Branisovska 1760, 37005 Ceske Budejovice, Czech Republic
- Center for Nanobiology and Structural Biology ASCR, Zamek 136, 37333 Nove Hrady, Czech Republic
| | - Andrea Fortova
- Loschmidt
Laboratories, Department of Experimental Biology and Research Centre
for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Artur Gora
- Loschmidt
Laboratories, Department of Experimental Biology and Research Centre
for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Iuliia Iermak
- Faculty
of Science, University of South Bohemia in Ceske Budejovice, Branisovska 1760, 37005 Ceske Budejovice, Czech Republic
- Center for Nanobiology and Structural Biology ASCR, Zamek 136, 37333 Nove Hrady, Czech Republic
| | - Pavlina Rezacova
- Institute of Organic Chemistry and Biochemistry ASCR, v.v.i. Flemingovo nam. 2, 166 10 Prague 6, Czech Republic
- Institute of Molecular Genetics of the ASCR, v.v.i. Videnska 1083, 142 20 Prague 4, Czech Republic
| | - Pavel Dvorak
- Loschmidt
Laboratories, Department of Experimental Biology and Research Centre
for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Ivana Kuta Smatanova
- Faculty
of Science, University of South Bohemia in Ceske Budejovice, Branisovska 1760, 37005 Ceske Budejovice, Czech Republic
- Center for Nanobiology and Structural Biology ASCR, Zamek 136, 37333 Nove Hrady, Czech Republic
| | - Zbynek Prokop
- Loschmidt
Laboratories, Department of Experimental Biology and Research Centre
for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Radka Chaloupkova
- Loschmidt
Laboratories, Department of Experimental Biology and Research Centre
for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Jiri Damborsky
- Loschmidt
Laboratories, Department of Experimental Biology and Research Centre
for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
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36
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Yan Z, Maruyama A, Arakawa T, Fushinobu S, Wakagi T. Crystal structures of archaeal 2-oxoacid:ferredoxin oxidoreductases from Sulfolobus tokodaii. Sci Rep 2016; 6:33061. [PMID: 27619895 PMCID: PMC5020499 DOI: 10.1038/srep33061] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 08/16/2016] [Indexed: 11/22/2022] Open
Abstract
As the first three-dimensional structure of the two-subunit type 2-oxoacid:ferredoxin oxidoreductases (OFOR) from archaea, we solved the crystal structures of STK_23000/STK_22980 (StOFOR1) and STK_24350/STK_24330 (StOFOR2) from Sulfolobus tokodaii. They showed similar overall structures, consisting of two a- and b-subunit heterodimers containing thiamin pyrophosphate (TPP) cofactor and [4Fe-4S] cluster, but lack an intramolecular ferredoxin domain. Unlike other OFORs, StOFORs can utilize both pyruvate and 2-oxoglutarate, playing a key role in the central metabolism. In the structure of StOFOR2 in unreacted pyruvate complex form, carboxylate group of pyruvate is recognized by Arg344 and Thr257 from the a-subunit, which are conserved in pyruvate:ferredoxin oxidoreductase from Desulfovbrio africanus (DaPFOR). In the structure of StOFOR1 co-crystallized with 2-oxobutyrate, electron density corresponding to a 1-hydroxypropyl group (post-decarboxylation state) was observed at the thiazole ring of TPP. The binding pockets of the StOFORs surrounding the methyl or propyl group of the ligands are wider than that of DaPFOR. Mutational analyses indicated that several residues were responsible for the broad 2-oxoacid specificity of StOFORs. We also constructed a possible complex structural model by placing a Zn(2+)-containing dicluster ferredoxin of S. tokodaii into the large pocket of StOFOR2, providing insight into the electron transfer between the two redox proteins.
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Affiliation(s)
- Zhen Yan
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Akane Maruyama
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Takatoshi Arakawa
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Shinya Fushinobu
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Takayoshi Wakagi
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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Buddrus L, Andrews ESV, Leak DJ, Danson MJ, Arcus VL, Crennell SJ. Crystal structure of pyruvate decarboxylase from Zymobacter palmae. Acta Crystallogr F Struct Biol Commun 2016; 72:700-6. [PMID: 27599861 PMCID: PMC5012210 DOI: 10.1107/s2053230x16012012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 07/23/2016] [Indexed: 11/10/2022] Open
Abstract
Pyruvate decarboxylase (PDC; EC 4.1.1.1) is a thiamine pyrophosphate- and Mg(2+) ion-dependent enzyme that catalyses the non-oxidative decarboxylation of pyruvate to acetaldehyde and carbon dioxide. It is rare in bacteria, but is a key enzyme in homofermentative metabolism, where ethanol is the major product. Here, the previously unreported crystal structure of the bacterial pyruvate decarboxylase from Zymobacter palmae is presented. The crystals were shown to diffract to 2.15 Å resolution. They belonged to space group P21, with unit-cell parameters a = 204.56, b = 177.39, c = 244.55 Å and Rr.i.m. = 0.175 (0.714 in the highest resolution bin). The structure was solved by molecular replacement using PDB entry 2vbi as a model and the final R values were Rwork = 0.186 (0.271 in the highest resolution bin) and Rfree = 0.220 (0.300 in the highest resolution bin). Each of the six tetramers is a dimer of dimers, with each monomer sharing its thiamine pyrophosphate across the dimer interface, and some contain ethylene glycol mimicking the substrate pyruvate in the active site. Comparison with other bacterial PDCs shows a correlation of higher thermostability with greater tetramer interface area and number of interactions.
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Affiliation(s)
- Lisa Buddrus
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, England
| | - Emma S. V. Andrews
- School of Science, Faculty of Science and Engineering, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand
| | - David J. Leak
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, England
| | - Michael J. Danson
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, England
| | - Vickery L. Arcus
- School of Science, Faculty of Science and Engineering, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand
| | - Susan J. Crennell
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, England
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Liu Y, Li Y, Wang X. Acetohydroxyacid synthases: evolution, structure, and function. Appl Microbiol Biotechnol 2016; 100:8633-49. [DOI: 10.1007/s00253-016-7809-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 07/28/2016] [Accepted: 08/12/2016] [Indexed: 10/21/2022]
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39
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Leng Y, Fu L, Ye L, Li B, Xu X, Xing X, He J, Song Y, Leng C, Guo Y, Ji X, Lu Z. Protein-directed synthesis of highly monodispersed, spherical gold nanoparticles and their applications in multidimensional sensing. Sci Rep 2016; 6:28900. [PMID: 27353703 PMCID: PMC4926111 DOI: 10.1038/srep28900] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 06/10/2016] [Indexed: 12/11/2022] Open
Abstract
An in-situ reduction method has been reported to prepare gold nanoparticles (GNPs) of 40–110 nm by using the green reducing agents of proteins, which are activated by H2O2 and the superoxide anion (). The protein of collagen turns HAuCl4 to the aqueous Au(I) ainions, which are further reduced by other proteins to be highly monodispersed and spherical GNPs of different sizes. The GNPs reduced by different proteins are found to be with the exposed {100} facets, the distinctive UV-vis absorption spectra and various colors (See Fig. 1). By means of extracting the color responses, such as red, green and blue (RGB) alterations, an in-situ reduction method-based multidimensional sensing platform is fabricated in the process of GNPs synthesis. Without further modification of GNPs, nine common proteins are found to be well detected and discriminated at different concentrations. Moreover, this sensing platform also demonstrates great potentials in qualitative and semiquantitative analysis on the individuals of these proteins with high sensitivity. Furthermore, the validation of this multidimensional sensing platform has been carried out by analysis on the spiked proteins in human urine and the target proteins in complex matrix (e.g. lysozyme in human tear).
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Affiliation(s)
- Yumin Leng
- College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061, China
| | - Ling Fu
- College of Agricultural Engineering, Nanyang Normal University, Nanyang 473061, China
| | - Liqun Ye
- College of Chemistry and Pharmaceutical Engineering, Nanyang Normal University, Nanyang 473061, China
| | - Bo Li
- College of Chemistry and Pharmaceutical Engineering, Nanyang Normal University, Nanyang 473061, China
| | - Xiumei Xu
- College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061, China
| | - Xiaojing Xing
- College of Chemistry and Pharmaceutical Engineering, Nanyang Normal University, Nanyang 473061, China
| | - Junbao He
- College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061, China
| | - Yuling Song
- College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061, China
| | - Chaoliang Leng
- College of Agricultural Engineering, Nanyang Normal University, Nanyang 473061, China
| | - Yongming Guo
- College of Chemistry and Pharmaceutical Engineering, Nanyang Normal University, Nanyang 473061, China
| | - Xiaoxu Ji
- College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061, China
| | - Zhiwen Lu
- College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061, China
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Jirgis ENM, Bashiri G, Bulloch EMM, Johnston JM, Baker EN. Structural Views along the Mycobacterium tuberculosis MenD Reaction Pathway Illuminate Key Aspects of Thiamin Diphosphate-Dependent Enzyme Mechanisms. Structure 2016; 24:1167-77. [PMID: 27291649 DOI: 10.1016/j.str.2016.04.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 04/19/2016] [Accepted: 04/27/2016] [Indexed: 01/19/2023]
Abstract
Menaquinone (MQ) is an essential component of the respiratory chains of many pathogenic organisms, including Mycobacterium tuberculosis (Mtb). The first committed step in MQ biosynthesis is catalyzed by 2-succinyl-5-enolpyruvyl-6-hydroxy-3-cyclohexadiene-1-carboxylate synthase (MenD), a thiamin diphosphate (ThDP)-dependent enzyme. Catalysis proceeds through two covalent intermediates as the substrates 2-oxoglutarate and isochorismate are successively added to the cofactor before final cleavage of the product. We have determined a series of crystal structures of Mtb-MenD that map the binding of both substrates, visualizing each step in the MenD catalytic cycle, including both intermediates. ThDP binding induces a marked asymmetry between the coupled active sites of each dimer, and possible mechanisms of communication can be identified. The crystal structures also reveal conformational features of the two intermediates that facilitate reaction but prevent premature product release. These data fully map chemical space to inform early-stage drug discovery targeting MenD.
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Affiliation(s)
- Ehab N M Jirgis
- Maurice Wilkins Centre for Molecular Biodiscovery, School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland 1010, New Zealand
| | - Ghader Bashiri
- Maurice Wilkins Centre for Molecular Biodiscovery, School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland 1010, New Zealand
| | - Esther M M Bulloch
- Maurice Wilkins Centre for Molecular Biodiscovery, School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland 1010, New Zealand
| | - Jodie M Johnston
- Maurice Wilkins Centre for Molecular Biodiscovery, School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland 1010, New Zealand.
| | - Edward N Baker
- Maurice Wilkins Centre for Molecular Biodiscovery, School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland 1010, New Zealand.
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41
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Nauton L, Hélaine V, Théry V, Hecquet L. Insights into the Thiamine Diphosphate Enzyme Activation Mechanism: Computational Model for Transketolase Using a Quantum Mechanical/Molecular Mechanical Method. Biochemistry 2016; 55:2144-52. [PMID: 26998737 DOI: 10.1021/acs.biochem.5b00787] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We propose the first computational model for transketolase (TK), a thiamine diphosphate (ThDP)-dependent enzyme, using a quantum mechanical/molecular mechanical method on the basis of crystallographic TK structures from yeast and Escherichia coli, together with experimental kinetic data reported in the literature with wild-type and mutant TK. This model allowed us to define a new route for ThDP activation in the enzyme environment. We evidenced a strong interaction between ThDP and Glu418B of the TK active site, itself stabilized by Glu162A. The crucial point highlighted here is that deprotonation of ThDP C2 is not performed by ThDP N4' as reported in the literature, but by His481B, involving a HOH688A molecule bridge. Thus, ThDP N4' is converted from an amino form to an iminium form, ensuring the stabilization of the C2 carbanion or carbene. Finally, ThDP activation proceeds via an intermolecular process and not by an intramolecular one as reported in the literature. More generally, this proposed ThDP activation mechanism can be applied to some other ThDP-dependent enzymes and used to define the entire TK mechanism with donor and acceptor substrates more accurately.
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Affiliation(s)
- Lionel Nauton
- Université Clermont Auvergne, Université Blaise-Pascal , Institut de Chimie de Clermont-Ferrand, BP 10448, F-63000 Clermont-Ferrand, France.,CNRS , UMR 6296, ICCF, F-63178 Aubiere, France
| | - Virgil Hélaine
- Université Clermont Auvergne, Université Blaise-Pascal , Institut de Chimie de Clermont-Ferrand, BP 10448, F-63000 Clermont-Ferrand, France.,CNRS , UMR 6296, ICCF, F-63178 Aubiere, France
| | - Vincent Théry
- Université Clermont Auvergne, Université Blaise-Pascal , Institut de Chimie de Clermont-Ferrand, BP 10448, F-63000 Clermont-Ferrand, France.,CNRS , UMR 6296, ICCF, F-63178 Aubiere, France
| | - Laurence Hecquet
- Université Clermont Auvergne, Université Blaise-Pascal , Institut de Chimie de Clermont-Ferrand, BP 10448, F-63000 Clermont-Ferrand, France.,CNRS , UMR 6296, ICCF, F-63178 Aubiere, France
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42
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Neumann P, Tittmann K. Marvels of enzyme catalysis at true atomic resolution: distortions, bond elongations, hidden flips, protonation states and atom identities. Curr Opin Struct Biol 2014; 29:122-33. [PMID: 25460275 DOI: 10.1016/j.sbi.2014.11.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 10/31/2014] [Accepted: 11/03/2014] [Indexed: 10/24/2022]
Abstract
Although general principles of enzyme catalysis are fairly well understood nowadays, many important details of how exactly the substrate is bound and processed in an enzyme remain often invisible and as such elusive. In fortunate cases, structural analysis of enzymes can be accomplished at true atomic resolution thus making possible to shed light on otherwise concealed fine-structural traits of bound substrates, intermediates, cofactors and protein groups. We highlight recent structural studies of enzymes using ultrahigh-resolution X-ray protein crystallography showcasing its enormous potential as a tool in the elucidation of enzymatic mechanisms and in unveiling fundamental principles of enzyme catalysis. We discuss the observation of seemingly hyper-reactive, physically distorted cofactors and intermediates with elongated scissile substrate bonds, the detection of 'hidden' conformational and chemical equilibria and the analysis of protonation states with surprising findings. In delicate cases, atomic resolution is required to unambiguously disclose the identity of atoms as demonstrated for the metal cluster in nitrogenase. In addition to the pivotal structural findings and the implications for our understanding of enzyme catalysis, we further provide a practical framework for resolution enhancement through optimized data acquisition and processing.
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Affiliation(s)
- Piotr Neumann
- Abteilung für Molekulare Strukturbiologie, Institut für Mikrobiologie und Genetik, Göttinger Zentrum für Molekulare Biowissenschaften (GZMB), Justus-von-Liebig-Weg 11, Georg-August-Universität Göttingen, Göttingen D-37077, Germany.
| | - Kai Tittmann
- Abteilung Molekulare Enzymologie, Göttinger Zentrum für Molekulare Biowissenschaften (GZMB), Justus-von-Liebig-Weg 11, Georg-August-Universität Göttingen, Göttingen D-37077, Germany.
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43
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van Zyl LJ, Schubert WD, Tuffin MI, Cowan DA. Structure and functional characterization of pyruvate decarboxylase from Gluconacetobacter diazotrophicus. BMC STRUCTURAL BIOLOGY 2014; 14:21. [PMID: 25369873 PMCID: PMC4428508 DOI: 10.1186/s12900-014-0021-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 09/25/2014] [Indexed: 11/10/2022]
Abstract
BACKGROUND Bacterial pyruvate decarboxylases (PDC) are rare. Their role in ethanol production and in bacterially mediated ethanologenic processes has, however, ensured a continued and growing interest. PDCs from Zymomonas mobilis (ZmPDC), Zymobacter palmae (ZpPDC) and Sarcina ventriculi (SvPDC) have been characterized and ZmPDC has been produced successfully in a range of heterologous hosts. PDCs from the Acetobacteraceae and their role in metabolism have not been characterized to the same extent. Examples include Gluconobacter oxydans (GoPDC), G. diazotrophicus (GdPDC) and Acetobacter pasteutrianus (ApPDC). All of these organisms are of commercial importance. RESULTS This study reports the kinetic characterization and the crystal structure of a PDC from Gluconacetobacter diazotrophicus (GdPDC). Enzyme kinetic analysis indicates a high affinity for pyruvate (K M 0.06 mM at pH 5), high catalytic efficiencies (1.3 • 10(6) M(-1) • s(-1) at pH 5), pHopt of 5.5 and Topt at 45°C. The enzyme is not thermostable (T½ of 18 minutes at 60°C) and the calculated number of bonds between monomers and dimers do not give clear indications for the relatively lower thermostability compared to other PDCs. The structure is highly similar to those described for Z. mobilis (ZmPDC) and A. pasteurianus PDC (ApPDC) with a rmsd value of 0.57 Å for Cα when comparing GdPDC to that of ApPDC. Indole-3-pyruvate does not serve as a substrate for the enzyme. Structural differences occur in two loci, involving the regions Thr341 to Thr352 and Asn499 to Asp503. CONCLUSIONS This is the first study of the PDC from G. diazotrophicus (PAL5) and lays the groundwork for future research into its role in this endosymbiont. The crystal structure of GdPDC indicates the enzyme to be evolutionarily closely related to homologues from Z. mobilis and A. pasteurianus and suggests strong selective pressure to keep the enzyme characteristics in a narrow range. The pH optimum together with reduced thermostability likely reflect the host organisms niche and conditions under which these properties have been naturally selected for. The lack of activity on indole-3-pyruvate excludes this decarboxylase as the enzyme responsible for indole acetic acid production in G. diazotrophicus.
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Affiliation(s)
- Leonardo J van Zyl
- Institute for Microbial Biotechnology and Metagenomics (IMBM), University of the Western Cape, Robert Sobukwe Road, Bellville, Cape Town, South Africa.
| | - Wolf-Dieter Schubert
- Department of Biochemistry, University of Pretoria, 2 Lynnwood Road, Pretoria, 0002, South Africa.
| | - Marla I Tuffin
- Institute for Microbial Biotechnology and Metagenomics (IMBM), University of the Western Cape, Robert Sobukwe Road, Bellville, Cape Town, South Africa.
| | - Don A Cowan
- Department of Genetics, University of Pretoria, Pretoria, 0002, South Africa.
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Khattak WA, Ullah MW, Ul-Islam M, Khan S, Kim M, Kim Y, Park JK. Developmental strategies and regulation of cell-free enzyme system for ethanol production: a molecular prospective. Appl Microbiol Biotechnol 2014; 98:9561-78. [PMID: 25359472 DOI: 10.1007/s00253-014-6154-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 10/09/2014] [Accepted: 10/12/2014] [Indexed: 10/24/2022]
Abstract
Most biomanufacturing systems developed for the production of biocommodities are based on whole-cell systems. However, with the advent of innovative technologies, the focus has shifted from whole-cell towards cell-free enzyme system. Since more than a century, researchers are using the cell-free extract containing the required enzymes and their respective cofactors in order to study the fundamental aspects of biological systems, particularly fermentation. Although yeast cell-free enzyme system is known since long ago, it is rarely been studied and characterized in detail. In this review, we hope to describe the major pitfalls encountered by whole-cell system and introduce possible solutions to them using cell-free enzyme systems. We have discussed the glycolytic and fermentative pathways and their regulation at both transcription and translational levels. Moreover, several strategies employed for development of cell-free enzyme system have been described with their potential merits and shortcomings associated with these developmental approaches. We also described in detail the various developmental approaches of synthetic cell-free enzyme system such as compartmentalization, metabolic channeling, protein fusion, and co-immobilization strategies. Additionally, we portrayed the novel cell-free enzyme technologies based on encapsulation and immobilization techniques and their development and commercialization. Through this review, we have presented the basics of cell-free enzyme system, the strategies involved in development and operation, and the advantages over conventional processes. Finally, we have addressed some potential directions for the future development and industrialization of cell-free enzyme system.
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Affiliation(s)
- Waleed Ahmad Khattak
- Department of Chemical Engineering, Kyungpook National University, Daegu, 7020-701, Korea
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45
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Tao Y, Ran X, Ren J, Qu X. Array-based sensing of proteins and bacteria by using multiple luminescent nanodots as fluorescent probes. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2014; 10:3667-3671. [PMID: 24840238 DOI: 10.1002/smll.201400661] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Indexed: 06/03/2023]
Abstract
Luminescent nanodots for protein sensing and discrimination of bacteria: Luminescent nanodots are applied as novel fluorescent probes in a sensing array. The sensing strategy uses graphene oxide (GO) for protein recognition, with displacement of fluorescent probes to generate the output. This sensing platform is a powerful tool to detect protein targets and discriminate bacteria.
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Affiliation(s)
- Yu Tao
- Laboratory of Chemical Biology, Division of Biological Inorganic Chemistry, State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Changchun, 130022, China; Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, Changchun, 130022, China
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46
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Patel MS, Nemeria NS, Furey W, Jordan F. The pyruvate dehydrogenase complexes: structure-based function and regulation. J Biol Chem 2014; 289:16615-23. [PMID: 24798336 DOI: 10.1074/jbc.r114.563148] [Citation(s) in RCA: 381] [Impact Index Per Article: 38.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The pyruvate dehydrogenase complexes (PDCs) from all known living organisms comprise three principal catalytic components for their mission: E1 and E2 generate acetyl-coenzyme A, whereas the FAD/NAD(+)-dependent E3 performs redox recycling. Here we compare bacterial (Escherichia coli) and human PDCs, as they represent the two major classes of the superfamily of 2-oxo acid dehydrogenase complexes with different assembly of, and interactions among components. The human PDC is subject to inactivation at E1 by serine phosphorylation by four kinases, an inactivation reversed by the action of two phosphatases. Progress in our understanding of these complexes important in metabolism is reviewed.
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Affiliation(s)
- Mulchand S Patel
- From the Department of Biochemistry, School of Medicine and Biomedical Sciences, University at Buffalo, the State University of New York, Buffalo, New York 14214,
| | - Natalia S Nemeria
- the Department of Chemistry, Rutgers, the State University of New Jersey, Newark, New Jersey 07102
| | - William Furey
- the Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, and the Veterans Affairs Medical Center, Pittsburgh, Pennsylvania 15240
| | - Frank Jordan
- the Department of Chemistry, Rutgers, the State University of New Jersey, Newark, New Jersey 07102,
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A dual conformation of the post-decarboxylation intermediate is associated with distinct enzyme states in mycobacterial KGD (α-ketoglutarate decarboxylase). Biochem J 2014; 457:425-34. [PMID: 24171907 DOI: 10.1042/bj20131142] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
α-Ketoacid dehydrogenases are large multi-enzyme machineries that orchestrate the oxidative decarboxylation of α-ketoacids with the concomitant production of acyl-CoA and NADH. The first reaction, catalysed by α-ketoacid decarboxylases (E1 enzymes), needs a thiamine diphosphate cofactor and represents the overall rate-limiting step. Although the catalytic cycles of E1 from the pyruvate dehydrogenase (E1p) and branched-chain α-ketoacid dehydrogenase (E1b) complexes have been elucidated, little structural information is available on E1o, the first component of the α-ketoglutarate dehydrogenase complex, despite the central role of this complex at the branching point between the TCA (tricarboxylic acid) cycle and glutamate metabolism. In the present study, we provide structural evidence that MsKGD, the E1o (α-ketoglutarate decarboxylase) from Mycobacterium smegmatis, shows two conformations of the post-decarboxylation intermediate, each one associated with a distinct enzyme state. We also provide an overall picture of the catalytic cycle, reconstructed by either crystallographic snapshots or modelling. The results of the present study show that the conformational change leading the enzyme from the initial (early) to the late state, although not required for decarboxylation, plays an essential role in catalysis and possibly in the regulation of mycobacterial E1o.
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48
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Bolze CS, Helbling RE, Owen RL, Pearson AR, Pompidor G, Dworkowski F, Fuchs MR, Furrer J, Golczak M, Palczewski K, Cascella M, Stocker A. Human cellular retinaldehyde-binding protein has secondary thermal 9-cis-retinal isomerase activity. J Am Chem Soc 2013; 136:137-46. [PMID: 24328211 DOI: 10.1021/ja411366w] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Cellular retinaldehyde-binding protein (CRALBP) chaperones 11-cis-retinal to convert opsin receptor molecules into photosensitive retinoid pigments of the eye. We report a thermal secondary isomerase activity of CRALBP when bound to 9-cis-retinal. UV/vis and (1)H NMR spectroscopy were used to characterize the product as 9,13-dicis-retinal. The X-ray structure of the CRALBP mutant R234W:9-cis-retinal complex at 1.9 Å resolution revealed a niche in the binding pocket for 9-cis-aldehyde different from that reported for 11-cis-retinal. Combined computational, kinetic, and structural data lead us to propose an isomerization mechanism catalyzed by a network of buried waters. Our findings highlight a specific role of water molecules in both CRALBP-assisted specificity toward 9-cis-retinal and its thermal isomerase activity yielding 9,13-dicis-retinal. Kinetic data from two point mutants of CRALBP support an essential role of Glu202 as the initial proton donor in this isomerization reaction.
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Affiliation(s)
- Christin S Bolze
- Department of Chemistry and Biochemistry, and ‡Graduate School for Cellular and Biomedical Sciences, University of Bern , Freiestrasse 3, 3012 Bern, Switzerland
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Karahka ML, Kreuzer HJ. Charge transport along proton wires. Biointerphases 2013; 8:13. [DOI: 10.1186/1559-4106-8-13] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2013] [Accepted: 06/07/2013] [Indexed: 11/10/2022] Open
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50
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Sheng X, Liu Y. Theoretical study of the catalytic mechanism of E1 subunit of pyruvate dehydrogenase multienzyme complex from Bacillus stearothermophilus. Biochemistry 2013; 52:8079-93. [PMID: 24171427 DOI: 10.1021/bi400577f] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Pyruvate dehydrogenase multienzyme complex (PDHc) is a member of a family of 2-oxo acid dehydrogenase (OADH) multienzyme complexes involved in several central points of oxidative metabolism, and the E1 subunit is the most important component in the entire PDHc catalytic system, which catalyzes the reversible transfer of an acetyl group from a pyruvate to the lipoyl group of E2 subunit lipoly domain. In this article, the catalytic mechanism of the E1 subunit has been systematically studied using density functional theory (DFT). Four possible pathways with different general acid/base catalysts in decarboxylation and reductive acylation processes were explored. Our calculation results indicate that the 4'-amino pyrimidine of ThDP and residue His128 are the most likely proton donors in the decarboxylation and reductive acylation processes, respectively. During the reaction, each C-C and C-S bond formation or cleavage process, except for the liberation of CO2, is always accompanied by a proton transfer between the substrates and proton donors. The liberation of CO2 is calculated to be the rate-limiting step for the overall reaction, with an energy barrier of 13.57 kcal/mol. The decarboxylation process is endothermic by 5.32 kcal/mol, whereas the reductive acylation process is exothermic with a value of 5.74 kcal/mol. The assignment of protonation states of the surrounding residues can greatly influence the reaction. Residues His128 and His271 play roles in positioning the first substrate pyruvate and second substrate lipoyl group, respectively.
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Affiliation(s)
- Xiang Sheng
- Key Laboratory of Theoretical and Computational Chemistry in Universities of Shandong, School of Chemistry and Chemical Engineering, Shandong University , Jinan, Shandong 250100, China
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