1
|
Tomita T. Structure, function, and regulation of enzymes involved in amino acid metabolism of bacteria and archaea. Biosci Biotechnol Biochem 2017; 81:2050-2061. [PMID: 28840778 DOI: 10.1080/09168451.2017.1365593] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Amino acids are essential components in all organisms because they are building blocks of proteins. They are also produced industrially and used for various purposes. For example, L-glutamate is used as the component of "umami" taste and lysine has been used as livestock feed. Recently, many kinds of amino acids have attracted attention as biological regulators and are used for a healthy life. Thus, to clarify the mechanism of how amino acids are biosynthesized and how they work as biological regulators will lead to further effective utilization of them. Here, I review the leucine-induced-allosteric activation of glutamate dehydrogenase (GDH) from Thermus thermophilus and the relationship with the allosteric regulation of GDH from mammals. Next, I describe structural insights into the efficient production of L-glutamate by GDH from an excellent L-glutamate producer, Corynebacterium glutamicum. Finally, I review the structural biology of lysine biosynthesis of thermophilic bacterium and archaea.
Collapse
Affiliation(s)
- Takeo Tomita
- a Department of Biotechnology, Biotechnology Research Center , The University of Tokyo , Tokyo , Japan
| |
Collapse
|
2
|
Takahashi K, Tomita T, Kuzuyama T, Nishiyama M. Determinants of dual substrate specificity revealed by the crystal structure of homoisocitrate dehydrogenase from Thermus thermophilus in complex with homoisocitrate·Mg(2+)·NADH. Biochem Biophys Res Commun 2016; 478:1688-93. [PMID: 27601325 DOI: 10.1016/j.bbrc.2016.09.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 09/01/2016] [Indexed: 11/17/2022]
Abstract
HICDH (Homoisocitrate dehydrogenase) is a member of the β-decarboxylating dehydrogenase family that catalyzes the conversion of homoisocitrate to α-ketoadipate using NAD(+) as a coenzyme, which is the fourth reaction involved in lysine biosynthesis through the α-aminoadipate pathway. Although typical HICDHs from fungi and yeast exhibit strict substrate specificities toward homoisocitrate (HIC), HICDH from a thermophilic bacterium Thermus thermophilus (TtHICDH) catalyzes the reactions using both HIC and isocitrate (IC) as substrates at similar efficiencies. We herein determined the crystal structure of the quaternary complex of TtHICDH with HIC, NADH, and Mg(2+) ion at a resolution of 2.5 Å. The structure revealed that the distal carboxyl group of HIC was recognized by the side chains of Ser72 and Arg85 from one subunit, and Asn173 from another subunit of a dimer unit. Model structures were constructed for TtHICDH in complex with IC and also for HICDH from Saccharomyces cerevisiae (ScHICDH) in complex with HIC. TtHICDH recognized the distal carboxyl group of IC by Arg85 in the model. In ScHICDH, the distal carboxyl group of HIC was recognized by the side chains of Ser98 and Ser108 from one subunit and Asn208 from another subunit of a dimer unit. By contrast, in ScHICDH, which lacks an Arg residue at the position corresponding to Arg85 in TtHICDH, these residues may not interact with the distal carboxyl group of shorter IC. These results provide a molecular basis for the differences in substrate specificities between TtHICDH and ScHICDH.
Collapse
Affiliation(s)
- Kento Takahashi
- Biotechnology Research Center, The University of Tokyo, Japan
| | - Takeo Tomita
- Biotechnology Research Center, The University of Tokyo, Japan
| | | | | |
Collapse
|
3
|
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]
|
4
|
Fazius F, Shelest E, Gebhardt P, Brock M. The fungal α-aminoadipate pathway for lysine biosynthesis requires two enzymes of the aconitase family for the isomerization of homocitrate to homoisocitrate. Mol Microbiol 2012; 86:1508-30. [PMID: 23106124 PMCID: PMC3556520 DOI: 10.1111/mmi.12076] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/15/2012] [Indexed: 11/30/2022]
Abstract
Fungi produce α-aminoadipate, a precursor for penicillin and lysine via the α-aminoadipate pathway. Despite the biotechnological importance of this pathway, the essential isomerization of homocitrate via homoaconitate to homoisocitrate has hardly been studied. Therefore, we analysed the role of homoaconitases and aconitases in this isomerization. Although we confirmed an essential contribution of homoaconitases from Saccharomyces cerevisiae and Aspergillus fumigatus, these enzymes only catalysed the interconversion between homoaconitate and homoisocitrate. In contrast, aconitases from fungi and the thermophilic bacterium Thermus thermophilus converted homocitrate to homoaconitate. Additionally, a single aconitase appears essential for energy metabolism, glutamate and lysine biosynthesis in respirating filamentous fungi, but not in the fermenting yeast S. cerevisiae that possesses two contributing aconitases. While yeast Aco1p is essential for the citric acid cycle and, thus, for glutamate synthesis, Aco2p specifically and exclusively contributes to lysine biosynthesis. In contrast, Aco2p homologues present in filamentous fungi were transcribed, but enzymatically inactive, revealed no altered phenotype when deleted and did not complement yeast aconitase mutants. From these results we conclude that the essential requirement of filamentous fungi for respiration versus the preference of yeasts for fermentation may have directed the evolution of aconitases contributing to energy metabolism and lysine biosynthesis.
Collapse
Affiliation(s)
- Felicitas Fazius
- Microbial Biochemistry and Physiology, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knoell-Institute, Beutenbergstr. 11a, 07745 Jena, Germany
| | | | | | | |
Collapse
|
5
|
Nango E, Yamamoto T, Kumasaka T, Eguchi T. Structure of Thermus thermophilus homoisocitrate dehydrogenase in complex with a designed inhibitor. J Biochem 2011; 150:607-14. [DOI: 10.1093/jb/mvr097] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
6
|
|
7
|
Nango E, Yamamoto T, Kumasaka T, Eguchi T. Crystal structure of 3-isopropylmalate dehydrogenase in complex with NAD(+) and a designed inhibitor. Bioorg Med Chem 2009; 17:7789-94. [PMID: 19833522 DOI: 10.1016/j.bmc.2009.09.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2009] [Revised: 09/12/2009] [Accepted: 09/15/2009] [Indexed: 10/20/2022]
Abstract
Isopropylmalate dehydrogenase (IPMDH) is the third enzyme specific to leucine biosynthesis in microorganisms and plants, and catalyzes the oxidative decarboxylation of (2R,3S)-3-isopropylmalate to alpha-ketoisocaproate using NAD(+) as an oxidizing agent. In this study, a thia-analogue of the substrate was designed and synthesized as an inhibitor for IPMDH. The analogue showed strong competitive inhibitory activity with K(i)=62nM toward IPMDH derived from Thermus thermophilus. Moreover, the crystal structure of T. thermophilus IPMDH in a ternary complex with NAD(+) and the inhibitor has been determined at 2.8A resolution. The inhibitor exists as a decarboxylated product with an enol/enolate form in the active site. The product interacts with Arg 94, Asn 102, Ser 259, Glu 270, and a water molecule hydrogen-bonding with Arg 132. All interactions between the product and the enzyme were observed in the position associated with keto-enol tautomerization. This result implies that the tautomerization step of the thia-analogue during the IPMDH reaction is involved in the inhibition.
Collapse
Affiliation(s)
- Eriko Nango
- Department of Chemistry, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo 152-8551, Japan
| | | | | | | |
Collapse
|
8
|
Aktas DF, Cook PF. A lysine-tyrosine pair carries out acid-base chemistry in the metal ion-dependent pyridine dinucleotide-linked beta-hydroxyacid oxidative decarboxylases. Biochemistry 2009; 48:3565-77. [PMID: 19281248 DOI: 10.1021/bi8022976] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This work reviews published structural and kinetic data on the pyridine nucleotide-linked beta-hydroxyacid oxidative decarboxylases. The family of metal ion-dependent pyridine nucleotide-linked beta-hydroxyacid oxidative decarboxylases can be divided into two structural families with the malic enzyme, which has an (S)-hydroxyacid substrate, comprising one subfamily and isocitrate dehydrogenase, isopropylmalate dehydrogenase, homoisocitrate dehydrogenase, and tartrate dehydrogenase, which have an (R)-hydroxyacid substrate, comprising the second subclass. Multiple-sequence alignment of the members of the (R)-hydroxyacid family indicates a high degree of sequence identity with most of the active site residues conserved. The three-dimensional structures of the members of the (R)-hydroxyacid family with structures available superimpose on one another, and the active site structures of the enzymes have a similar overall geometry of residues in the substrate and metal ion binding sites. In addition, a number of residues in the malic enzyme active site are also conserved, and the arrangement of these residues has a similar geometry, although the (R)-hydroxyacid and (S)-hydroxyacid family sites are geometrically mirror images of one another. The active sites of the (R)-hydroxyacid family have a higher positive charge density when compared to those of the (S)-hydroxyacid family, largely due to the number of arginine residues in the vicinity of the substrate alpha-carboxylate and one fewer carboxylate ligand to the divalent metal ion. Data available for all of the enzymes in the family have been considered, and a general mechanism that makes use of a lysine (general base)-tyrosine (general acid) pair is proposed. Differences exist in the mechanism for generating the neutral form of lysine so that it can act as a base.
Collapse
Affiliation(s)
- Deniz F Aktas
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, 73019, USA
| | | |
Collapse
|
9
|
Lin Y, Volkman J, Nicholas KM, Yamamoto T, Eguchi T, Nimmo SL, West AH, Cook PF. Chemical mechanism of homoisocitrate dehydrogenase from Saccharomyces cerevisiae. Biochemistry 2008; 47:4169-80. [PMID: 18321070 DOI: 10.1021/bi702361j] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Homoisocitrate dehydrogenase (HIcDH, 3-carboxy-2-hydroxyadipate dehydrogenase) catalyzes the fourth reaction of the alpha-aminoadipate pathway for lysine biosynthesis, the conversion of homoisocitrate to alpha-ketoadipate using NAD as an oxidizing agent. A chemical mechanism for HIcDH is proposed on the basis of the pH dependence of kinetic parameters, dissociation constants for competitive inhibitors, and isotope effects. According to the pH-rate profiles, two enzyme groups act as acid-base catalysts in the reaction. A group with a p K a of approximately 6.5-7 acts as a general base accepting a proton as the beta-hydroxy acid is oxidized to the beta-keto acid, and this residue participates in all three of the chemical steps, acting to shuttle a proton between the C2 hydroxyl and itself. The second group acts as a general acid with a p K a of 9.5 and likely catalyzes the tautomerization step by donating a proton to the enol to give the final product. The general acid is observed in only the V pH-rate profile with homoisocitrate as a substrate, but not with isocitrate as a substrate, because the oxidative decarboxylation portion of the isocitrate reaction is limiting overall. With isocitrate as the substrate, the observed primary deuterium and (13)C isotope effects indicate that hydride transfer and decarboxylation steps contribute to rate limitation, and that the decarboxylation step is the more rate-limiting of the two. The multiple-substrate deuterium/ (13)C isotope effects suggest a stepwise mechanism with hydride transfer preceding decarboxylation. With homoisocitrate as the substrate, no primary deuterium isotope effect was observed, and a small (13)C kinetic isotope effect (1.0057) indicates that the decarboxylation step contributes only slightly to rate limitation. Thus, the chemical steps do not contribute significantly to rate limitation with the native substrate. On the basis of data from solvent deuterium kinetic isotope effects, viscosity effects, and multiple-solvent deuterium/ (13)C kinetic isotope effects, the proton transfer step(s) is slow and likely reflects a conformational change prior to catalysis.
Collapse
Affiliation(s)
- Ying Lin
- Department of Chemistry and Biochemistry, University of Oklahoma, 620 Parrington Oval, Norman, Oklahoma 73019, USA
| | | | | | | | | | | | | | | |
Collapse
|
10
|
Lin Y, Alguindigue SS, Volkman J, Nicholas KM, West AH, Cook PF. Complete kinetic mechanism of homoisocitrate dehydrogenase from Saccharomyces cerevisiae. Biochemistry 2007; 46:890-8. [PMID: 17223711 PMCID: PMC2527762 DOI: 10.1021/bi062067q] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The kinetic mechanism of homoisocitrate dehydrogenase from Saccharomyces cerevisiae was determined using initial velocity studies in the absence and presence of product and dead end inhibitors in both reaction directions. Data suggest a steady state random kinetic mechanism. The dissociation constant of the Mg-homoisocitrate complex (MgHIc) was estimated to be 11 +/- 2 mM as measured using Mg2+ as a shift reagent. Initial velocity data indicate the MgHIc complex is the reactant in the direction of oxidative decarboxylation, while in the reverse reaction direction, the enzyme likely binds uncomplexed Mg2+ and alpha-ketoadipate. Curvature is observed in the double-reciprocal plots for product inhibition by NADH and the dead-end inhibition by 3-acetylpyridine adenine dinucleotide phosphate when MgHIc is the varied substrate. At low concentrations of MgHIc, the inhibition by both nucleotides is competitive, but as the MgHIc concentration increases, the inhibition changes to uncompetitive, consistent with a steady state random mechanism with preferred binding of MgHIc before NAD. Release of product is preferred and ordered with respect to CO2, alpha-ketoadipate, and NADH. Isocitrate is a slow substrate with a rate (V/E(t)) 216-fold slower than that measured with HIc. In contrast to HIc, the uncomplexed form of isocitrate and Mg2+ bind to the enzyme. The kinetic mechanism in the direction of oxidative decarboxylation of isocitrate, on the basis of initial velocity studies in the absence and presence of dead-end inhibitors, suggests random addition of NAD and isocitrate with Mg2+ binding before isocitrate in rapid equilibrium, and the mechanism approximates rapid equilibrium random. The Keq for the overall reaction measured directly using the change in NADH as a probe is 0.45 M.
Collapse
Affiliation(s)
| | | | | | | | | | - Paul F. Cook
- Corresponding author: E-mail: Tel: 405−325−4581 Fax: 405−325−7182
| |
Collapse
|
11
|
Expeditious biomimetically-inspired approaches to racemic homocitric acid lactone and per-homocitrate. Tetrahedron 2007. [DOI: 10.1016/j.tet.2006.12.092] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
12
|
Paju A, Kanger T, Pehk T, Eek M, Lopp M. A short enantioselective synthesis of homocitric acid-γ-lactone and 4-hydroxy-homocitric acid-γ-lactones. Tetrahedron 2004. [DOI: 10.1016/j.tet.2004.07.096] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
13
|
Schmitz C, Rouanet-Dreyfuss AC, Tueni M, Biellmann JF. Syntheses of (-)-Isocitric Acid Lactone and (-)-Homoisocitric Acid. A New Method of Conversion of Alkynylsilanes into the Alkynyl Thioether and Corresponding Carboxylic Acids. J Org Chem 1996; 61:1817-1821. [PMID: 11667054 DOI: 10.1021/jo951062o] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A simple, stereoselective synthesis of natural isocitric and homoisocitric acids from a common alkynylsilane correlates the stereochemistry of these acids. Starting with dimethyl D-malate dianion, methyl 2-hydroxy-3-carbomethoxy-6-(trimethylsilyl)-5-hexynoate (6a) was prepared with a good stereoselectivity (threo/erythro 90/10). Oxidative cleavage of the triple bond provided isocitric acid lactone (8') in 15% overall yield starting from D-malic acid diester 1. The synthesis of homoisocitric acid relied on a new method of conversion of alkynylsilane to alkynyl thioether, which is converted to the carboxylic acid of the same chain length. Addition of benzenesulfenyl chloride to (trimethylsilyl)alkyne 6b and elimination of trimethylsilyl chloride gave the corresponding thioether 10, which by acid hydrolysis gave homoisocitric acid (11) in a 24% yield from D-malic acid ester. This novel method of conversion of alkynylsilane to the corresponding acid was illustrated with several other alkynyltrimethylsilanes.
Collapse
Affiliation(s)
- Carole Schmitz
- Laboratoire de Chimie Organique Biologique associé au CNRS, Université Louis Pasteur, Faculté de Chimie, 1 rue Blaise Pascal, 67003 Strasbourg, France
| | | | | | | |
Collapse
|
14
|
Rodríguez R GH, Biellmann JF. Enantioselective Syntheses of (-)- and (+)-Homocitric Acid Lactones. J Org Chem 1996; 61:1822-1824. [PMID: 11667055 DOI: 10.1021/jo951063g] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Highly enantioselective syntheses of enantiomers of homocitric acid lactones (R)-5a and (S)-5b are described. Thermal Diels-Alder cycloadditions of 2a and 2b to 1,3-butadiene produced adducts 3a and 3b, respectively. Oxidative ozonolysis of latter adducts gave products 4a and 4b which after acid treatment afforded a mixture with 5a and 5b as major component. Acid lactones 5a and 5b were converted into their dimethyl esters 6a and 6b which were purified by chromatography. After saponification, the products obtained were crystallized to yield (-)- and (+)-homocitric acid lactones ((R)-5a and (S)-5b). Diastereomeric excess (de) of Diels-Alder adducts 3a and 3b was determined by means of Mosher esters of glycols 8a, 8b, and racemic 8. Diels-Alder cycloaddition products of lactones 2a and 2b to 1,3-butadiene showed a diastereoselectivity of 96%.
Collapse
Affiliation(s)
- Gastón H. Rodríguez R
- Laboratoire de Chimie Organique Biologique Associé au CNRS 31, Institut de Chimie, Faculté de Chimie, Université Louis Pasteur, 1, rue Blaise Pascal, F67008 Strasbourg, France
| | | |
Collapse
|
15
|
Garrad RC, Bhattacharjee JK. Lysine biosynthesis in selected pathogenic fungi: characterization of lysine auxotrophs and the cloned LYS1 gene of Candida albicans. J Bacteriol 1992; 174:7379-84. [PMID: 1429460 PMCID: PMC207434 DOI: 10.1128/jb.174.22.7379-7384.1992] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The alpha-aminoadipate pathway for the biosynthesis of lysine is present only in fungi and euglena. Until now, this unique metabolic pathway has never been investigated in the opportunistic fungal pathogens Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus. Five of the eight enzymes (homocitrate synthase, homoisocitrate dehydrogenase, alpha-aminoadipate reductase, saccharopine reductase, and saccharopine dehydrogenase) of the alpha-aminoadipate pathway and glucose-6-phosphate dehydrogenase, a glycolytic enzyme used as a control, were demonstrated in wild-type cells of these organisms. All enzymes were present in Saccharomyces cerevisiae and the pathogenic organisms except C. neoformans 32608 serotype C, which exhibited no saccharopine reductase activity. The levels of enzyme activity varied considerably from strain to strain. Variation among organisms was also observed for the control enzyme. Among the pathogens, C. albicans exhibited much higher homocitrate synthase, homoisocitrate dehydrogenase, and alpha-aminoadipate reductase activities. Seven lysine auxotrophs of C. albicans and one of Candida tropicalis were characterized biochemically to determine the biochemical blocks and gene-enzyme relationships. Growth responses to alpha-aminoadipate- and lysine-supplemented media, accumulation of alpha-aminoadipate semialdehyde, and the lack of enzyme activity revealed that five of the mutants (WA104, WA153, WC7-1-3, WD1-31-2, and A5155) were blocked at the alpha-aminoadipate reductase step, two (STN57 and WD1-3-6) were blocked at the saccharopine dehydrogenase step, and the C. tropicalis mutant (X-16) was blocked at the saccharopine reductase step. The cloned LYS1 gene of C. albicans in the recombinant plasmid YpB1078 complemented saccharopine dehydrogenase (lys1) mutants of S. cerevisiae and C. albicans. The Lys1+ transformed strains exhibited significant saccharopine dehydrogenase activity in comparison with untransformed mutants. The cloned LYS1 gene has been localized on a 1.8-kb HindIII DNA insert of the recombinant plasmid YpB1041RG1. These results established the gene-enzyme relationship in the second half of the alpha-aminoadipate pathway. The presence of this unique pathway in the pathogenic fungi could be useful for their rapid detection and control.
Collapse
Affiliation(s)
- R C Garrad
- Department of Microbiology, Miami University, Oxford, Ohio 45056
| | | |
Collapse
|
16
|
Schmitz C, Rouanet-Dreyfuss AC, Tueni M, Biellman JF. Short and efficient syntheses of (−) -isocitric acid lactone and (−) -homoisocitric acid. Conversion of alkynylsilanes into the corresponding carboxylic acids. Tetrahedron Lett 1992. [DOI: 10.1016/s0040-4039(00)61231-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
17
|
Ye ZH, Garrad RC, Winston MK, Bhattacharjee JK. Use of alpha-aminoadipate and lysine as sole nitrogen source by Schizosaccharomyces pombe and selected pathogenic fungi. J Basic Microbiol 1991; 31:149-56. [PMID: 1908900 DOI: 10.1002/jobm.3620310215] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
alpha-Aminodipate, an intermediate of the lysine biosynthetic pathway of fungi, or lysine when used as the sole nitrogen source in the medium was growth inhibitory and toxic to Saccharomyces cerevisiae. The fission yeast Schizosaccharomyces pombe and pathogenic fungi Candida albicans, Filobasidiella neoformans and Aspergillus fumigatus grew in the medium containing alpha-aminoadipate as the sole nitrogen source. C. albicans, A. fumigatus, and one of the strains of F. neoformans also grew in the medium containing lysine as the sole nitrogen source. When grown in the alpha-aminoadipate medium, only S. pombe accumulated a significant amount of alpha-ketoadipate in the culture supernatant. Also, 14C-alpha-aminoadipate was converted to 14C-alpha-ketoadipate in vivo. In the ammonium sulfate medium, S. pombe cells converted 14C-alpha-aminoadipate to lysine. The levels of glutamate-alpha-ketoadipate transaminase, an enzyme responsible for the conversion of alpha-aminoadipate to alpha-ketoadipate, and alpha-aminoadipate reductase, an enzyme required for the conversion of alpha-aminoadipate to lysine, were similar in S. pombe cells grown in the alpha-aminoadipate or ammonium sulfate medium. However, the level of homoisocitrate dehydrogenase, an enzyme before the alpha-ketoadipate step, was twelvefold lower in S. pombe cells grown in the alpha-aminoadipate medium compared to the level in cells grown in the ammonium sulfate medium. Pathogenic fungi used in this study did not accumulate alpha-ketoadipate and alpha-aminoadipate-delta-semialdehyde when grown in medium containing alpha-aminoadipate and lysine, respectively, as sole nitrogen source. However, only pathogenic fungi used both lysine and alpha-aminoadipate as sole nitrogen source. This unique metabolic property could be useful for the identification of these pathogens.
Collapse
Affiliation(s)
- Z H Ye
- Department of Microbiology, Miami University, Oxford, Ohio 45056
| | | | | | | |
Collapse
|
18
|
Winston MK, Bhattacharjee JK. Biosynthetic and regulatory role of lys9 mutants of Saccharomyces cerevisiae. Curr Genet 1987; 11:393-8. [PMID: 3131025 DOI: 10.1007/bf00378182] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Derepression of lysine biosynthetic enzymes of Saccharomyces cerevisiae was investigated in lys9 auxotrophs which lack saccharopine reductase activity. Five enzymes (homocitrate synthase, homoisocitrate dehydrogenase, alpha-aminoadipate aminotransferase, alpha-aminoadipate reductase and saccharopine dehydrogenase) were constitutively derepressed in all lys9 mutants with up to eight-fold higher enzyme levels than in isogenic wild-type cells. Levels of these enzymes in lys2, lys14, and lys15 mutants were the same or lower than those in wild-type cells. The regulatory property of lys9 mutants exhibited recessiveness to the wild-type gene in heterozygous diploids. Unlike the mating type effect, homozygous diploids resulting from crosses between lys9 auxotrophs exhibited even higher levels of derepressed enzymes than the haploid mutants. Addition of a higher concentration of lysine to the growth medium resulted in reduction of enzyme levels although they were still derepressed. These results suggest that lys9 mutants represent a lesion for the saccharopine reductase and may represent a repressor mutation which in the wild-type cells simultaneously represses unlinked structural genes that encode for five of the lysine biosynthetic enzymes.
Collapse
Affiliation(s)
- M K Winston
- Department of Microbiology, Miami University, Oxford, OH 45056
| | | |
Collapse
|
19
|
Urrestarazu LA, Borell CW, Bhattacharjee JK. General and specific controls of lysine biosynthesis in Saccharomyces cerevisiae. Curr Genet 1985; 9:341-4. [PMID: 3939712 DOI: 10.1007/bf00421603] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Six of the eight enzymes of the alpha-aminoadipate pathway for the biosynthesis of lysine in Saccharomyces cerevisiae were examined for repressibility to lysine and for susceptibility to the general control of amino acid biosynthesis. All of the enzymes exhibited a 2 to 4 fold lower level of specific activity in the wildtype strain X2180 when grown in lysine supplemented medium as compared to minimal medium. However, levels of only three of the enzymes, alpha-aminoadipate reductase, saccharopine reductase, and saccharopine dehydrogenase, were derepressed in the leaky lysine mutant 7305d and leaky arginine mutant 7853-6c when grown in minimal medium. These observations are characteristic of enzymes under general control of amino acid biosynthesis. The remaining three enzymes, homocitrate synthetase, homoaconitase and homoisocitrate dehydrogenase were repressed in 7305d cells grown in minimal or lysine supplemented medium.
Collapse
Affiliation(s)
- L A Urrestarazu
- Department of Microbiology, Miami University, Oxford, Ohio 45056
| | | | | |
Collapse
|
20
|
Bhattacharjee JK. alpha-Aminoadipate pathway for the biosynthesis of lysine in lower eukaryotes. Crit Rev Microbiol 1985; 12:131-51. [PMID: 3928261 DOI: 10.3109/10408418509104427] [Citation(s) in RCA: 124] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Bacteria and green plants use the diaminopimelate pathway for the biosynthesis of the essential amino acid, lysine; however, yeast and other higher fungi use the alpha-aminoadipate (AA) pathway. The AA pathway has been investigated in detail biochemically, genetically, and in terms of regulatory mechanisms in the baker's yeast Saccharomyces cerevisiae. The genetic analysis of lysine auxotrophs of S. cerevisiae revealed that there are more than 12 lysine genes for 8 enzyme-catalyzed steps. Lysine genes are not linked to each other and seven of the genes are mapped on six different linkage groups (chromosomes). The gene-enzyme relationships have been determined for ten of the lysine loci which include two unlinked gene functions required for each of AA reductase (LYS2 and LYS5) and Saccharopine reductase (LYS9 and LYS14). Five of the lysine enzymes are localized in mitochondria and three in cytosol. The lysine pathway of S. cerevisiae is regulated by feedback inhibition and end product repression. Two, and possibly three, of the enzymes exhibit general control of amino acid biosynthesis and at least five of the enzymes coded for, by unlinked genes, are simultaneously depressed in a regulatory (repressor) gene-mutant.
Collapse
|
21
|
Gaillardin CM, Ribet AM, Heslot H. Wild-type and mutant forms of homoisocitric dehydrogenase in the yeast Saccharomycopsis lipolytica. EUROPEAN JOURNAL OF BIOCHEMISTRY 1982; 128:489-94. [PMID: 6759120 DOI: 10.1111/j.1432-1033.1982.tb06991.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Homoisocitric dehydrogenase (EC 1.1.1.155) has been purified 525-fold from the yeast Saccharomycopsis lipolytica with a yield of 25%. The preparation was judged to be homogeneous by electrophoresis under denaturing and non-denaturing conditions and by isoelectric focusing; it consisted of a single protein with molecular weight of 48000. In the presence of homoisocitric acid, a higher molecular weight was observed, suggesting a dimeric structure for the native enzyme. Complementing mutants devoid of homoisocitric dehydrogenase activity mapped at two closely linked loci (lys9 and lys10). Lys10 mutants displayed NAD-reducing activity, whereas lys9 mutants retained some carboxylating activity. Our results are best explained by the assumption that the active enzyme is a dimer of identical subunits involved in successive dehydrogenation and decarboxylation steps.
Collapse
|
22
|
Winston MK, Bhattacharjee JK. Growth inhibition by alpha-aminoadipate and reversal of the effect by specific amino acid supplements in Saccharomyces cerevisiae. J Bacteriol 1982; 152:874-9. [PMID: 6752121 PMCID: PMC221542 DOI: 10.1128/jb.152.2.874-879.1982] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The growth of Saccharomyces cerevisiae wild-type strain X2180 in minimal medium was inhibited by the addition of higher-than-supplementary levels of alpha-aminoadipate. This inhibitory effect was reversed by the addition of arginine, asparagine, aspartate, glutamine, homoserine, methionine, or serine as single amino acid supplements. Mutants belonging to the lys2 and lys14 loci were able to grow in lysine-supplemented alpha-aminoadipate medium, although not as well as when selected amino acids were added. Growth in alpha-aminoadipate medium by all strains was accompanied by an accumulation of alpha-ketoadipate. Glutamate:keto-adipate transaminase levels were derepressed two- to fivefold in lys2 mutants using alpha-aminoadipate as a nitrogen source. Wild-type strain X2180 growing in amino acid-supplemented AA medium exhibited higher levels of alpha-aminoadipate reductase. Mutants unable to use alpha-aminoadipate without amino acid supplementation were obtained by treatment of lys2 strain MW5-64 and were shown to have glutamate: ketoadipate transaminase activity and to lack alpha-aminoadipate reductase activity. Altered cell morphologies, including increased size, multiple buds, pseudohyphae, and germ tubes, evidenced by cells grown in alpha-aminoadipate medium suggest that higher-than-supplementary levels of alpha-aminoadipate result in an impairment of cell division.
Collapse
|
23
|
|
24
|
Musílková M, Panos J, Sedmera P, Fencl Z. Accumulation of 2-oxo acids in mutants of Aspergillus niger requiring lysine. Folia Microbiol (Praha) 1980; 25:324-7. [PMID: 6774936 DOI: 10.1007/bf02876613] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Mutants of Aspergillus niger 194A and 178 requiring lysine differ from the original prototrophic strain K10 and from each other on the course of accumulation of organic acids. In both mutants less citric acid accumulates during the first phase of cultivation but considerably more 2-oxoglutarate and 2-oxoadipate accumulate than in the original strain. Whereas in the 194A mutant this state remains unchanged also during the second phase of cultivation, in the 178 mutant oxo acids are degraded and citric acid is synthesized intensively. The accumulation of 2-oxoglutarate and 2-oxoadipate in the fermentation medium indicates that in A. niger lysine is synthesized via the homocitrate pathway.
Collapse
|
25
|
Sinha AK, Kurtz M, Bhattacharjee JK. Effect of hydroxylysine on the biosynthesis of lysine in saccharomyces. J Bacteriol 1971; 108:715-9. [PMID: 5128332 PMCID: PMC247130 DOI: 10.1128/jb.108.2.715-719.1971] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Hydroxylysine acts as a growth inhibitor of Saccharomyces for a certain period of time. The inhibition is concentration-dependent and is reversed by a small amount of lysine in the medium. After the growth-inhibitory period, the wild-type cells are able to grow rapidly even in the presence of hydroxylysine. Both lysine auxotrophs and wild-type cells are unable to utilize hydroxylysine in place of lysine. Hydroxylysine, mimicking lysine, controls the biosynthesis of lysine and thereby limits the availability of biosynthetic lysine to the cells. Hydroxylysine affects the biosynthesis of lysine at a number of enzymatic steps. Accumulation of homocitric acid, the first intermediate of lysine biosynthesis, in the mutant strains 19B and A B9 is reduced significantly in the presence of hydroxylysine. Hydroxylysine, like lysine, exerts a significant inhibition in vitro on the homocitric acid-synthesizing activity. Enzymes following the alpha-aminoadipic acid step respond in a noncoordinate fashion to hydroxylysine. Level of the enzyme saccharopine reductase, but not of alpha-aminoadipic acid reductase or saccharopine dehydrogenase, is reduced significantly. These regulatory effects of hydroxylysine are similar to those observed for lysine.
Collapse
|
26
|
[157b] cis-homoaconitase. Methods Enzymol 1971. [DOI: 10.1016/0076-6879(71)17023-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
27
|
|
28
|
Bhattacharjee JK, Tucci AF. Relationship of Glutaric Acid to the Homocitric Acid Pathway of Biosynthesis of Lysine in Yeast. J Biol Chem 1969. [DOI: 10.1016/s0021-9258(18)91777-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
|
29
|
|
30
|
Bhattacharjee JK, Tucci AF, Strassman M. Accumulation of alpha-ketoglutaric acid in yeast mutants requiring lysine. Arch Biochem Biophys 1968; 123:235-9. [PMID: 5642593 DOI: 10.1016/0003-9861(68)90129-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
|
31
|
|
32
|
Strassman M, Ceci LN. Enzymatic Formation of cis-Homoaconitic Acid, an Intermediate in Lysine Biosynthesis in Yeast. J Biol Chem 1966. [DOI: 10.1016/s0021-9258(18)96444-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
|
33
|
Maragoudakis ME, Strassman M. Homocitric Acid Accumulation by a Lysine-requiring Yeast Mutant. J Biol Chem 1966. [DOI: 10.1016/s0021-9258(18)96894-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
|