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Ohtsuka H, Shimasaki T, Aiba H. Response to leucine in Schizosaccharomyces pombe (fission yeast). FEMS Yeast Res 2022; 22:6553821. [PMID: 35325114 PMCID: PMC9041340 DOI: 10.1093/femsyr/foac020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 03/08/2022] [Accepted: 03/22/2022] [Indexed: 11/13/2022] Open
Abstract
Leucine (Leu) is a branched-chain, essential amino acid in animals, including humans. Fungi, including the fission yeast Schizosaccharomyces pombe, can biosynthesize Leu, but deletion of any of the genes in this biosynthesis leads to Leu auxotrophy. In this yeast, although a mutation in the Leu biosynthetic pathway, leu1-32, is clearly inconvenient for this species, it has increased its usefulness as a model organism in laboratories worldwide. Leu auxotrophy produces intracellular responses and phenotypes different from those of the prototrophic strains, depending on the growing environment, which necessitates a certain degree of caution in the analysis and interpretation of the experimental results. Under amino acid starvation, the amino acid-auxotrophic yeast induces cellular responses, which are conserved in higher organisms without the ability of synthesizing amino acids. This mini-review focuses on the roles of Leu in S. pombe and discusses biosynthetic pathways, contribution to experimental convenience using a plasmid specific for Leu auxotrophic yeast, signaling pathways, and phenotypes caused by Leu starvation. An accurate understanding of the intracellular responses brought about by Leu auxotrophy can contribute to research in various fields using this model organism and to the understanding of intracellular responses in higher organisms that cannot synthesize Leu.
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Affiliation(s)
- Hokuto Ohtsuka
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan
| | - Takafumi Shimasaki
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan
| | - Hirofumi Aiba
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan
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2
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Comparative Proteomic Analysis of Light-Induced Mycelial Brown Film Formation in Lentinula edodes. BIOMED RESEARCH INTERNATIONAL 2016; 2016:5837293. [PMID: 27868065 PMCID: PMC5102706 DOI: 10.1155/2016/5837293] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 09/21/2016] [Indexed: 11/18/2022]
Abstract
Light-induced brown film (BF) formation by the vegetative mycelium of Lentinula edodes is important for ensuring the quantity and quality of this edible mushroom. Nevertheless, the molecular mechanism underlying this phenotype is still unclear. In this study, a comparative proteomic analysis of mycelial BF formation in L. edodes was performed. Seventy-three protein spots with at least a twofold difference in abundance on two-dimensional electrophoresis (2DE) maps were observed, and 52 of them were successfully identified by matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry (MALDI-TOF/TOF/MS). These proteins were classified into the following functional categories: small molecule metabolic processes (39%), response to oxidative stress (5%), and organic substance catabolic processes (5%), followed by oxidation-reduction processes (3%), single-organism catabolic processes (3%), positive regulation of protein complex assembly (3%), and protein metabolic processes (3%). Interestingly, four of the proteins that were upregulated in response to light exposure were nucleoside diphosphate kinases. To our knowledge, this is the first proteomic analysis of the mechanism of BF formation in L. edodes. Our data will provide a foundation for future detailed investigations of the proteins linked to BF formation.
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3
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Characterization of two β-decarboxylating dehydrogenases from Sulfolobus acidocaldarius. Extremophiles 2016; 20:843-853. [DOI: 10.1007/s00792-016-0872-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 08/25/2016] [Indexed: 11/26/2022]
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Gráczer É, Szimler T, Garamszegi A, Konarev PV, Lábas A, Oláh J, Palló A, Svergun DI, Merli A, Závodszky P, Weiss MS, Vas M. Dual Role of the Active Site Residues of Thermus thermophilus 3-Isopropylmalate Dehydrogenase: Chemical Catalysis and Domain Closure. Biochemistry 2016; 55:560-74. [PMID: 26731489 DOI: 10.1021/acs.biochem.5b00839] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The key active site residues K185, Y139, D217, D241, D245, and N102 of Thermus thermophilus 3-isopropylmalate dehydrogenase (Tt-IPMDH) have been replaced, one by one, with Ala. A drastic decrease in the kcat value (0.06% compared to that of the wild-type enzyme) has been observed for the K185A and D241A mutants. Similarly, the catalytic interactions (Km values) of these two mutants with the substrate IPM are weakened by more than 1 order of magnitude. The other mutants retained some (1-13%) of the catalytic activity of the wild-type enzyme and do not exhibit appreciable changes in the substrate Km values. The pH dependence of the wild-type enzyme activity (pK = 7.4) is shifted toward higher values for mutants K185A and D241A (pK values of 8.4 and 8.5, respectively). For the other mutants, smaller changes have been observed. Consequently, K185 and D241 may constitute a proton relay system that can assist in the abstraction of a proton from the OH group of IPM during catalysis. Molecular dynamics simulations provide strong support for the neutral character of K185 in the resting state of the enzyme, which implies that K185 abstracts the proton from the substrate and D241 assists the process via electrostatic interactions with K185. Quantum mechanics/molecular mechanics calculations revealed a significant increase in the activation energy of the hydride transfer of the redox step for both D217A and D241A mutants. Crystal structure analysis of the molecular contacts of the investigated residues in the enzyme-substrate complex revealed their additional importance (in particular that of K185, D217, and D241) in stabilizing the domain-closed active conformation. In accordance with this, small-angle X-ray scattering measurements indicated the complete absence of domain closure in the cases of D217A and D241A mutants, while only partial domain closure could be detected for the other mutants. This suggests that the same residues that are important for catalysis are also essential for inducing domain closure.
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Affiliation(s)
- Éva Gráczer
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences , Magyar tudósok krt. 2., H-1117 Budapest, Hungary
| | - Tamás Szimler
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences , Magyar tudósok krt. 2., H-1117 Budapest, Hungary
| | - Anita Garamszegi
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences , Magyar tudósok krt. 2., H-1117 Budapest, Hungary
| | - Petr V Konarev
- European Molecular Biology Laboratory , Hamburg Outstation, Notkestrasse 85, 22603 Hamburg, Germany
| | - Anikó Lábas
- Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics , Gellért tér 4., H-1111 Budapest, Hungary
| | - Julianna Oláh
- Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics , Gellért tér 4., H-1111 Budapest, Hungary
| | - Anna Palló
- Institute of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences , Magyar tudósok krt. 2., H-1117 Budapest, Hungary
| | - Dmitri I Svergun
- European Molecular Biology Laboratory , Hamburg Outstation, Notkestrasse 85, 22603 Hamburg, Germany
| | - Angelo Merli
- Dipartimento di Bioscienze, Universitá degli Studi di Parma , Viale G.P. Usberti 23/A, I-43100 Parma, Italy
| | - Péter Závodszky
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences , Magyar tudósok krt. 2., H-1117 Budapest, Hungary
| | - Manfred S Weiss
- Macromolecular Crystallography (HZB-MX), Helmholtz-Zentrum Berlin für Materialien und Energie , Albert-Einstein-Strasse 15, D-12489 Berlin, Germany
| | - Mária Vas
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences , Magyar tudósok krt. 2., H-1117 Budapest, Hungary
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Ronda L, Bruno S, Bettati S, Storici P, Mozzarelli A. From protein structure to function via single crystal optical spectroscopy. Front Mol Biosci 2015; 2:12. [PMID: 25988179 PMCID: PMC4428442 DOI: 10.3389/fmolb.2015.00012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 03/31/2015] [Indexed: 11/23/2022] Open
Abstract
The more than 100,000 protein structures determined by X-ray crystallography provide a wealth of information for the characterization of biological processes at the molecular level. However, several crystallographic “artifacts,” including conformational selection, crystallization conditions and radiation damages, may affect the quality and the interpretation of the electron density maps, thus limiting the relevance of structure determinations. Moreover, for most of these structures, no functional data have been obtained in the crystalline state, thus posing serious questions on their validity in infereing protein mechanisms. In order to solve these issues, spectroscopic methods have been applied for the determination of equilibrium and kinetic properties of proteins in the crystalline state. These methods are UV-vis spectrophotometry, spectrofluorimetry, IR, EPR, Raman, and resonance Raman spectroscopy. Some of these approaches have been implemented with on-line instruments at X-ray synchrotron beamlines. Here, we provide an overview of investigations predominantly carried out in our laboratory by single crystal polarized absorption UV-vis microspectrophotometry, the most applied technique for the functional characterization of proteins in the crystalline state. Studies on hemoglobins, pyridoxal 5′-phosphate dependent enzymes and green fluorescent protein in the crystalline state have addressed key biological issues, leading to either straightforward structure-function correlations or limitations to structure-based mechanisms.
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Affiliation(s)
- Luca Ronda
- Department of Neurosciences, University of Parma Parma, Italy
| | - Stefano Bruno
- Department of Pharmacy, University of Parma Parma, Italy
| | - Stefano Bettati
- Department of Neurosciences, University of Parma Parma, Italy ; National Institute of Biostructures and Biosystems Rome, Italy
| | | | - Andrea Mozzarelli
- Department of Pharmacy, University of Parma Parma, Italy ; National Institute of Biostructures and Biosystems Rome, Italy ; Institute of Biophysics, Consiglio Nazionale delle Ricerche Pisa, Italy
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Palló A, Oláh J, Gráczer E, Merli A, Závodszky P, Weiss MS, Vas M. Structural and energetic basis of isopropylmalate dehydrogenase enzyme catalysis. FEBS J 2014; 281:5063-76. [PMID: 25211160 DOI: 10.1111/febs.13044] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 09/06/2014] [Accepted: 09/08/2014] [Indexed: 01/17/2023]
Abstract
UNLABELLED The three-dimensional structure of the enzyme 3-isopropylmalate dehydrogenase from the bacterium Thermus thermophilus in complex with Mn(2+) , its substrate isopropylmalate and its co-factor product NADH at 2.0 Å resolution features a fully closed conformation of the enzyme. Upon closure of the two domains, the substrate and the co-factor are brought into precise relative orientation and close proximity, with a distance between the C2 atom of the substrate and the C4N atom of the pyridine ring of the co-factor of approximately 3.0 Å. The structure further shows binding of a K(+) ion close to the active site, and provides an explanation for its known activating effect. Hence, this structure is an excellent mimic for the enzymatically competent complex. Using high-level QM/MM calculations, it may be demonstrated that, in the observed arrangement of the reactants, transfer of a hydride from the C2 atom of 3-isopropylmalate to the C4N atom of the pyridine ring of NAD(+) is easily possible, with an activation energy of approximately 15 kcal·mol(-1) . The activation energy increases by approximately 4-6 kcal·mol(-1) when the K(+) ion is omitted from the calculations. In the most plausible scenario, prior to hydride transfer the ε-amino group of Lys185 acts as a general base in the reaction, aiding the deprotonation reaction of 3-isopropylmalate prior to hydride transfer by employing a low-barrier proton shuttle mechanism involving a water molecule. DATABASE Structural data have been submitted to the Protein Data Bank under accession number 4F7I.
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Affiliation(s)
- Anna Palló
- Institute of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
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Vorobieva AA, Khan MS, Soumillion P. Escherichia coli D-malate dehydrogenase, a generalist enzyme active in the leucine biosynthesis pathway. J Biol Chem 2014; 289:29086-96. [PMID: 25160617 DOI: 10.1074/jbc.m114.595363] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The enzymes of the β-decarboxylating dehydrogenase superfamily catalyze the oxidative decarboxylation of D-malate-based substrates with various specificities. Here, we show that, in addition to its natural function affording bacterial growth on D-malate as a carbon source, the D-malate dehydrogenase of Escherichia coli (EcDmlA) naturally expressed from its chromosomal gene is capable of complementing leucine auxotrophy in a leuB(-) strain lacking the paralogous isopropylmalate dehydrogenase enzyme. To our knowledge, this is the first example of an enzyme that contributes with a physiologically relevant level of activity to two distinct pathways of the core metabolism while expressed from its chromosomal locus. EcDmlA features relatively high catalytic activity on at least three different substrates (L(+)-tartrate, D-malate, and 3-isopropylmalate). Because of these properties both in vivo and in vitro, EcDmlA may be defined as a generalist enzyme. Phylogenetic analysis highlights an ancient origin of DmlA, indicating that the enzyme has maintained its generalist character throughout evolution. We discuss the implication of these findings for protein evolution.
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Affiliation(s)
- Anastassia A Vorobieva
- From the Laboratoire de Biochimie, Biophysique et Génétique des Microorganismes (BBGM), Institut des Sciences de la Vie, Université catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium and
| | | | - Patrice Soumillion
- From the Laboratoire de Biochimie, Biophysique et Génétique des Microorganismes (BBGM), Institut des Sciences de la Vie, Université catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium and
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Miller SP, Gonçalves S, Matias PM, Dean AM. Evolution of a transition state: role of Lys100 in the active site of isocitrate dehydrogenase. Chembiochem 2014; 15:1145-53. [PMID: 24797066 DOI: 10.1002/cbic.201400040] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Indexed: 11/09/2022]
Abstract
An active site lysine essential to catalysis in isocitrate dehydrogenase (IDH) is absent from related enzymes. As all family members catalyze the same oxidative β-decarboxylation at the (2R)-malate core common to their substrates, it seems odd that an amino acid essential to one is not found in all. Ordinarily, hydride transfer to a nicotinamide C4 neutralizes the positive charge at N1 directly. In IDH, the negatively charged C4-carboxylate of isocitrate stabilizes the ground state positive charge on the adjacent nicotinamide N1, opposing hydride transfer. The critical lysine is poised to stabilize-and perhaps even protonate-an oxyanion formed on the nicotinamide 3-carboxamide, thereby enabling the hydride to be transferred while the positive charge at N1 is maintained. IDH might catalyze the same overall reaction as other family members, but dehydrogenation proceeds through a distinct, though related, transition state. Partial activation of lysine mutants by K(+) and NH4 (+) represents a throwback to the primordial state of the first promiscuous substrate family member.
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Affiliation(s)
- Stephen P Miller
- Biotechnology Institute, The University of Minnesota, 1479 Gortner Avenue, St. Paul, MN 55108 (USA)
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Gráczer É, Lionne C, Závodszky P, Chaloin L, Vas M. Transient kinetic studies reveal isomerization steps along the kinetic pathway ofThermus thermophilus3-isopropylmalate dehydrogenase. FEBS J 2013; 280:1764-72. [DOI: 10.1111/febs.12191] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Revised: 02/08/2013] [Accepted: 02/11/2013] [Indexed: 11/30/2022]
Affiliation(s)
- Éva Gráczer
- Institute of Enzymology; Research Centre for Natural Sciences; Hungarian Academy of Sciences; Budapest; Hungary
| | - Corinne Lionne
- Centre d'études d'agents Pathogènes et Biotechnologies pour la Santé (CPBS); UMR 5236 CNRS; University Montpellier I, University Montpellier II; France
| | - Péter Závodszky
- Institute of Enzymology; Research Centre for Natural Sciences; Hungarian Academy of Sciences; Budapest; Hungary
| | - Laurent Chaloin
- Centre d'études d'agents Pathogènes et Biotechnologies pour la Santé (CPBS); UMR 5236 CNRS; University Montpellier I, University Montpellier II; France
| | - Mária Vas
- Institute of Enzymology; Research Centre for Natural Sciences; Hungarian Academy of Sciences; Budapest; Hungary
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Gráczer É, Konarev PV, Szimler T, Bacsó A, Bodonyi A, Svergun DI, Závodszky P, Vas M. Essential role of the metal-ion in the IPM-assisted domain closure of 3-isopropylmalate dehydrogenase. FEBS Lett 2011; 585:3297-302. [DOI: 10.1016/j.febslet.2011.09.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Revised: 09/06/2011] [Accepted: 09/08/2011] [Indexed: 11/27/2022]
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