1
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Santos JL, Ângelo EA, Gauze GDF, Seixas FAV, Canduri F. Heterologous overexpression and characterization of homoserine dehydrogenase from Paracoccidioides brasiliensis. Biochimie 2023; 211:87-95. [PMID: 36934778 DOI: 10.1016/j.biochi.2023.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 03/03/2023] [Accepted: 03/10/2023] [Indexed: 03/19/2023]
Abstract
The enzyme Homoserine dehydrogenase from Paracoccidioides brasiliensis (PbHSD), an interesting enzyme in the search for new antifungal drugs against paracoccidioidomycosis, was expressed by E. coli. Thirty milligrams of PbHSD with 94% of purity were obtained per liter of culture medium. The analysis by CD spectroscopy indicates a composition of 45.5 ± 7.3% of α-helices and 10.5 ± 7.0% β-strands. Gel filtration chromatography indicates a homodimer as biological unity. Fluorescence emission spectroscopy has shown stability of PbHSD in the presence of urea until Cm of 4.13 ± 0.21 M, and a broad pH range in which there is no conformational change. The protein analysis by differential scanning calorimetry indicates high stability at room temperature, but low stability at high temperatures, suffering irreversible denaturation, with Tm = 58.65 ± 0.87 °C. Kinetic studies of PbHSD by molecular absorption spectroscopy in UV/Vis have shown an optimum pH between 9.35 and 9.50, with Michaelian behavior, presenting KM of 224 ± 15 μM and specific activity at optimum pH of 2.10 ± 0.07 μmol/min/mg for homoserine. Therefore, protein expression and purification were efficient, and the structural characterization has shown that PbHSD presents native conformation with enzymatic activity in kinetic assays.
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Affiliation(s)
- Jessyka Lima Santos
- São Carlos Institute of Chemistry, Universidade de São Paulo, São Carlos, SP, Brazil
| | | | | | | | - Fernanda Canduri
- São Carlos Institute of Chemistry, Universidade de São Paulo, São Carlos, SP, Brazil.
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2
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Liang X, Deng H, Bai Y, Fan TP, Zheng X, Cai Y. Characterization of a novel type homoserine dehydrogenase with high oxidation activity from Arthrobacter nicotinovorans. Process Biochem 2022. [DOI: 10.1016/j.procbio.2022.01.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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3
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Tang W, Dong X, Meng J, Feng Y, Xie M, Xu H, Song P. Biochemical characterization and redesign of the coenzyme specificity of a novel monofunctional NAD +-dependent homoserine dehydrogenase from the human pathogen Neisseria gonorrhoeae. Protein Expr Purif 2021; 186:105909. [PMID: 34022392 DOI: 10.1016/j.pep.2021.105909] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 05/13/2021] [Accepted: 05/15/2021] [Indexed: 12/17/2022]
Abstract
Gonorrhoea, caused by Neisseria gonorrhoeae, is a major global public health concern. Homoserine dehydrogenase (HSD), a key enzyme in the aspartate pathway, is a promising metabolic target against pathogenic infections. In this study, a monofunctional HSD from N. gonorrhoeae (NgHSD) was overexpressed in Escherichia coli and purified to >95% homogeneity for biochemical characterization. Unlike the classic dimeric structure, the purified recombinant NgHSD exists as a tetramer in solution. We determined the enzymatic activity of recombinant NgHSD for l-homoserine oxidation, which revealed that this enzyme was NAD+ dependent, with an approximate 479-fold (kcat/Km) preference for NAD+ over NADP+, and that optimal activity for l-homoserine oxidation occurred at pH 10.5 and 40 °C. At 800 mM, neither NaCl nor KCl increased the activity of NgHSD, in contrast to the behavior of several reported NAD+-independent homologs. Moreover, threonine did not markedly inhibit the oxidation activity of NgHSD. To gain insight into the cofactor specificity, site-directed mutagenesis was used to alter coenzyme specificity. The double mutant L45R/S46R, showing the highest affinity for NADP+, caused a shift in coenzyme preference from NAD+ to NADP+ by a factor of ~974, with a catalytic efficiency comparable with naturally occurring NAD+-independent homologs. Collectively, our results should allow the exploration of drugs targeting NgHSD to treat gonococcal infections and contribute to the prediction of the coenzyme specificity of novel HSDs.
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Affiliation(s)
- Wanggang Tang
- Department of Biochemistry and Molecular Biology, School of Laboratory Medicine, Bengbu Medical College, Bengbu, Anhui, 233030, China.
| | - Xue Dong
- Research Center of Laboratory Medicine, School of Laboratory Medicine, Bengbu Medical College, Bengbu, Anhui, 233030, China
| | - Jiang Meng
- Research Center of Laboratory Medicine, School of Laboratory Medicine, Bengbu Medical College, Bengbu, Anhui, 233030, China
| | - Yanan Feng
- Research Center of Laboratory Medicine, School of Laboratory Medicine, Bengbu Medical College, Bengbu, Anhui, 233030, China
| | - Manman Xie
- Research Center of Laboratory Medicine, School of Laboratory Medicine, Bengbu Medical College, Bengbu, Anhui, 233030, China
| | - Haonan Xu
- Research Center of Laboratory Medicine, School of Laboratory Medicine, Bengbu Medical College, Bengbu, Anhui, 233030, China
| | - Ping Song
- College of Biological and Food Engineering, Anhui Polytechnic University, Wuhu, Anhui, 241000, China.
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4
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Sastoque A, Triana S, Ehemann K, Suarez L, Restrepo S, Wösten H, de Cock H, Fernández-Niño M, González Barrios AF, Celis Ramírez AM. New Therapeutic Candidates for the Treatment of Malassezia pachydermatis -Associated Infections. Sci Rep 2020; 10:4860. [PMID: 32184419 PMCID: PMC7078309 DOI: 10.1038/s41598-020-61729-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 02/24/2020] [Indexed: 11/26/2022] Open
Abstract
The opportunistic pathogen Malassezia pachydermatis causes bloodstream infections in preterm infants or individuals with immunodeficiency disorders and has been associated with a broad spectrum of diseases in animals such as seborrheic dermatitis, external otitis and fungemia. The current approaches to treat these infections are failing as a consequence of their adverse effects, changes in susceptibility and antifungal resistance. Thus, the identification of novel therapeutic targets against M. pachydermatis infections are highly relevant. Here, Gene Essentiality Analysis and Flux Variability Analysis was applied to a previously reported M. pachydermatis metabolic network to identify enzymes that, when absent, negatively affect biomass production. Three novel therapeutic targets (i.e., homoserine dehydrogenase (MpHSD), homocitrate synthase (MpHCS) and saccharopine dehydrogenase (MpSDH)) were identified that are absent in humans. Notably, L-lysine was shown to be an inhibitor of the enzymatic activity of MpHCS and MpSDH at concentrations of 1 mM and 75 mM, respectively, while L-threonine (1 mM) inhibited MpHSD. Interestingly, L- lysine was also shown to inhibit M. pachydermatis growth during in vitro assays with reference strains and canine isolates, while it had a negligible cytotoxic activity on HEKa cells. Together, our findings form the bases for the development of novel treatments against M. pachydermatis infections.
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Affiliation(s)
- Angie Sastoque
- Instituto de Biotecnología (IBUN), Facultad de Ciencias, Universidad Nacional de Colombia, Bogotá, 11001, Colombia
- Grupo de Investigación Celular y Molecular de Microorganismos Patógenos (CeMoP), Departamento de Ciencias Biológicas, Universidad de los Andes, Bogotá, 111711, Colombia
- Grupo de Diseño de Productos y Procesos (GDPP), Departamento de Ingeniería Química, Universidad de los Andes, Bogotá, 111711, Colombia
| | - Sergio Triana
- Grupo de Investigación Celular y Molecular de Microorganismos Patógenos (CeMoP), Departamento de Ciencias Biológicas, Universidad de los Andes, Bogotá, 111711, Colombia
- Grupo de Diseño de Productos y Procesos (GDPP), Departamento de Ingeniería Química, Universidad de los Andes, Bogotá, 111711, Colombia
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, 69117, Germany
- Collaboration for joint PhD degree between EMBL and Heidelberg University, Faculty of Biosciences, Heidelberg, Germany
| | - Kevin Ehemann
- Grupo de Investigación Celular y Molecular de Microorganismos Patógenos (CeMoP), Departamento de Ciencias Biológicas, Universidad de los Andes, Bogotá, 111711, Colombia
| | - Lina Suarez
- Grupo de Diseño de Productos y Procesos (GDPP), Departamento de Ingeniería Química, Universidad de los Andes, Bogotá, 111711, Colombia
| | - Silvia Restrepo
- Laboratorio de Micología y Fitopatología (LAMFU), Departamento de Ingeniería Química, Universidad de los Andes, Bogotá, 111711, Colombia
| | - Han Wösten
- Microbiology, Department of Biology, Utrecht University, Utrecht, The Netherlands
| | - Hans de Cock
- Microbiology, Department of Biology, Utrecht University, Utrecht, The Netherlands
| | - Miguel Fernández-Niño
- Grupo de Diseño de Productos y Procesos (GDPP), Departamento de Ingeniería Química, Universidad de los Andes, Bogotá, 111711, Colombia
| | - Andrés Fernando González Barrios
- Grupo de Diseño de Productos y Procesos (GDPP), Departamento de Ingeniería Química, Universidad de los Andes, Bogotá, 111711, Colombia.
| | - Adriana Marcela Celis Ramírez
- Grupo de Investigación Celular y Molecular de Microorganismos Patógenos (CeMoP), Departamento de Ciencias Biológicas, Universidad de los Andes, Bogotá, 111711, Colombia.
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Ohshida T, Koba K, Hayashi J, Yoneda K, Ohmori T, Ohshima T, Sakuraba H. A novel bifunctional aspartate kinase-homoserine dehydrogenase from the hyperthermophilic bacterium, Thermotoga maritima. Biosci Biotechnol Biochem 2018; 82:2084-2093. [DOI: 10.1080/09168451.2018.1511365] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
ABSTRACT
The orientation of the three domains in the bifunctional aspartate kinase-homoserine dehydrogenase (AK-HseDH) homologue found in Thermotoga maritima totally differs from those observed in previously known AK-HseDHs; the domains line up in the order HseDH, AK, and regulatory domain. In the present study, the enzyme produced in Escherichia coli was characterized. The enzyme exhibited substantial activities of both AK and HseDH. l-Threonine inhibits AK activity in a cooperative manner, similar to that of Arabidopsis thaliana AK-HseDH. However, the concentration required to inhibit the activity was much lower (K0.5 = 37 μM) than that needed to inhibit the A. thaliana enzyme (K0.5 = 500 μM). In contrast to A. thaliana AK-HseDH, Hse oxidation of the T. maritima enzyme was almost impervious to inhibition by l-threonine. Amino acid sequence comparison indicates that the distinctive sequence of the regulatory domain in T. maritima AK-HseDH is likely responsible for the unique sensitivity to l-threonine.
Abbreviations: AK: aspartate kinase; HseDH: homoserine dehydrogenase; AK–HseDH: bifunctional aspartate kinase–homoserine dehydrogenase; AsaDH: aspartate–β–semialdehyde dehydrogenase; ACT: aspartate kinases (A), chorismate mutases (C), and prephenate dehydrogenases (TyrA, T).
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Affiliation(s)
- Tatsuya Ohshida
- Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, Kagawa, Japan
| | - Kohei Koba
- Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, Kagawa, Japan
| | - Junji Hayashi
- Department of Biotechnology, College of Life Sciences, Biwako-Kusatsu Campus, Ritsumeikan University, Shiga, Japan
| | - Kazunari Yoneda
- Department of Bioscience, School of Agriculture, Tokai University, Kumamoto, Japan
| | - Taketo Ohmori
- Department of Biomedical Engineering, Faculty of Engineering, Osaka Institute of Technology, Osaka, Japan
| | - Toshihisa Ohshima
- Department of Biomedical Engineering, Faculty of Engineering, Osaka Institute of Technology, Osaka, Japan
| | - Haruhiko Sakuraba
- Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, Kagawa, Japan
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Hagel JM, Facchini PJ. Tying the knot: occurrence and possible significance of gene fusions in plant metabolism and beyond. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:4029-4043. [PMID: 28521055 DOI: 10.1093/jxb/erx152] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Gene fusions have recently attracted attention especially in the field of plant specialized metabolism. The occurrence of a gene fusion, in which originally separate gene products are combined into a single polypeptide, often corresponds to the functional association of individual components within a single metabolic pathway. Examples include gene fusions implicated in benzylisoquinoline alkaloid (BIA), terpenoid, and amino acid biosynthetic pathways, in which distinct domains within a fusion catalyze consecutive, yet independent reactions. Both genomic and transcriptional mechanisms result in the fusion of gene products, which can include partial or complete domain repeats and extensive domain shuffling as evident in the BIA biosynthetic enzyme norcoclaurine synthase. Artificial gene fusions are commonly deployed in attempts to engineer new or improved pathways in plants or microorganisms, based on the premise that fusions are advantageous. However, a survey of functionally characterized fusions in microbial systems shows that the functional impact of fused gene products is not straightforward. For example, whereas enzyme fusions might facilitate the metabolic channeling of unstable intermediates, this channeling can also occur between tightly associated independent enzymes. The frequent occurrence of both fused and unfused enzymes in plant and microbial metabolism adds additional complexity, in terms of both pathway functionality and evolution.
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Affiliation(s)
- Jillian M Hagel
- Department of Biological Sciences, University of Calgary, 2500 University Dr N.W., Alberta T2N 1N4, Canada
| | - Peter J Facchini
- Department of Biological Sciences, University of Calgary, 2500 University Dr N.W., Alberta T2N 1N4, Canada
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7
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Tsai PW, Chien CY, Yeh YC, Tung L, Chen HF, Chang TH, Lan CY. Candida albicans Hom6 is a homoserine dehydrogenase involved in protein synthesis and cell adhesion. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2016; 50:863-871. [PMID: 27089825 DOI: 10.1016/j.jmii.2016.03.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 02/22/2016] [Accepted: 03/09/2016] [Indexed: 10/22/2022]
Abstract
BACKGROUND/PURPOSE Candida albicans is a common fungal pathogen in humans. In healthy individuals, C. albicans represents a harmless commensal organism, but infections can be life threatening in immunocompromised patients. The complete genome sequence of C. albicans is extremely useful for identifying genes that may be potential drug targets and important for pathogenic virulence. However, there are still many uncharacterized genes in the Candida genome database. In this study, we investigated C. albicans Hom6, the functions of which remain undetermined experimentally. METHODS HOM6-deleted and HOM6-reintegrated mutant strains were constructed. The mutant strains were compared with wild-type in their growth in various media and enzyme activity. Effects of HOM6 deletion on translation were further investigated by cell susceptibility to hygromycin B or cycloheximide, as well as by polysome profiling, and cell adhesion to polystyrene was also determined. RESULTS C. albicans Hom6 exhibits homoserine dehydrogenase activity and is involved in the biosynthesis of methionine and threonine. HOM6 deletion caused translational arrest in cells grown under amino acid starvation conditions. Additionally, Hom6 protein was found in both cytosolic and cell-wall fractions of cultured cells. Furthermore, HOM6 deletion reduced C. albicans cell adhesion to polystyrene, which is a common plastic used in many medical devices. CONCLUSION Given that there is no Hom6 homologue in mammalian cells, our results provided an important foundation for future development of new antifungal drugs.
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Affiliation(s)
- Pei-Wen Tsai
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan
| | - Chu-Yang Chien
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan
| | - Ying-Chieh Yeh
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan
| | - Luh Tung
- Genomics Research Center, Academia Sinica, Nankang, Taipei, Taiwan
| | - Hsueh-Fen Chen
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan
| | - Tien-Hsien Chang
- Genomics Research Center, Academia Sinica, Nankang, Taipei, Taiwan
| | - Chung-Yu Lan
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan; Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan.
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8
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Hayashi J, Inoue S, Kim K, Yoneda K, Kawarabayasi Y, Ohshima T, Sakuraba H. Crystal Structures of a Hyperthermophilic Archaeal Homoserine Dehydrogenase Suggest a Novel Cofactor Binding Mode for Oxidoreductases. Sci Rep 2015; 5:11674. [PMID: 26154028 PMCID: PMC4495429 DOI: 10.1038/srep11674] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 06/02/2015] [Indexed: 11/15/2022] Open
Abstract
NAD(P)-dependent dehydrogenases differ according to their coenzyme preference: some prefer NAD, others NADP, and still others exhibit dual cofactor specificity. The structure of a newly identified archaeal homoserine dehydrogenase showed this enzyme to have a strong preference for NADP. However, NADP did not act as a cofactor with this enzyme, but as a strong inhibitor of NAD-dependent homoserine oxidation. Structural analysis and site-directed mutagenesis showed that the large number of interactions between the cofactor and the enzyme are responsible for the lack of reactivity of the enzyme towards NADP. This observation suggests this enzyme exhibits a new variation on cofactor binding to a dehydrogenase: very strong NADP binding that acts as an obstacle to NAD(P)-dependent dehydrogenase catalytic activity.
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Affiliation(s)
- Junji Hayashi
- Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, Ikenobe 2393, Miki-cho, Kagawa 761-0795, Japan
| | - Shota Inoue
- Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, Ikenobe 2393, Miki-cho, Kagawa 761-0795, Japan
| | - Kwang Kim
- Department of Biological Sciences, Graduate School of Science, Osaka University, Osaka 560-0043, Japan
| | - Kazunari Yoneda
- Department of Bioscience, School of Agriculture, Tokai University, Aso, Kumamoto, 869-1404, Japan
| | - Yutaka Kawarabayasi
- Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Amagasaki 661-0974, Japan
| | - Toshihisa Ohshima
- Department of Biomedical Engineering, Faculty of Engineering, Osaka Institute of Technology, 5-16-1, Ohmiya, Asahi-ku, Osaka, 535-8585, Japan
| | - Haruhiko Sakuraba
- Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, Ikenobe 2393, Miki-cho, Kagawa 761-0795, Japan
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9
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Navratna V, Reddy G, Gopal B. Structural basis for the catalytic mechanism of homoserine dehydrogenase. ACTA ACUST UNITED AC 2015; 71:1216-25. [DOI: 10.1107/s1399004715004617] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 03/05/2015] [Indexed: 11/10/2022]
Abstract
Homoserine dehydrogenase (HSD) is an oxidoreductase in the aspartic acid pathway. This enzyme coordinates a critical branch point of the metabolic pathway that leads to the synthesis of bacterial cell-wall components such as L-lysine andm-DAP in addition to other amino acids such as L-threonine, L-methionine and L-isoleucine. Here, a structural rationale for the hydride-transfer step in the reaction mechanism of HSD is reported. The structure ofStaphylococcus aureusHSD was determined at different pH conditions to understand the basis for the enhanced enzymatic activity at basic pH. An analysis of the crystal structure revealed that Lys105, which is located at the interface of the catalytic and cofactor-binding sites, could mediate the hydride-transfer step of the reaction mechanism. The role of Lys105 was subsequently confirmed by mutational analysis. Put together, these studies reveal the role of conserved water molecules and a lysine residue in hydride transfer between the substrate and the cofactor.
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10
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Yuan H, Liu D. Genetic evidence that Arabidopsis ALTERED ROOT ARCHITECTURE encodes a putative dehydrogenase involved in homoserine biosynthesis. PLANT CELL REPORTS 2014; 33:25-33. [PMID: 24101201 DOI: 10.1007/s00299-013-1509-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 09/11/2013] [Accepted: 09/20/2013] [Indexed: 06/02/2023]
Abstract
Genetic and molecular analysis of an Arabidopsis root development mutant identified a putative dehydrogenase gene involved in homoserine biosynthesis. In higher plants, homoserine (Hse) is derived from aspartate (Asp) and is an important intermediate for production of methionine (Met), threonine (Thr), and isoleucine (Ile). In Arabidopsis, six enzymes involved in the biosynthesis of Hse from Asp have been well characterized. It is not known, however, whether there exist other enzymes involved in this process. In this work, we characterized an Arabidopsis mutant, ara (altered root architecture), with a short primary root and an increased number of lateral roots. Genetic and molecular analysis indicated that the ARA gene encodes a protein with a D-isomer specific 2-hydroxyacid dehydrogenase domain. ARA is expressed in all plant organs and is localized in the cell periphery. The ara mutant phenotypes can be rescued by exogenously applied Hse, Met, Ile and 2-oxobutanoate. Based on the results presented here, we propose that the ARA protein may be a dehydrogenase involved in homoserine biosynthesis.
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Affiliation(s)
- Hui Yuan
- MOE Key Laboratory of Bioinformatics, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, People's Republic of China
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11
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Galant A, Koester RP, Ainsworth EA, Hicks LM, Jez JM. From climate change to molecular response: redox proteomics of ozone-induced responses in soybean. THE NEW PHYTOLOGIST 2012; 194:220-229. [PMID: 22272738 DOI: 10.1111/j.1469-8137.2011.04037.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
• Ozone (O₃) causes significant agricultural losses, with soybean (Glycine max) being highly sensitive to this oxidant. Here we assess the effect of elevated seasonal O₃ exposure on the total and redox proteomes of soybean. • To understand the molecular responses to O₃ exposure, soybean grown at the Soybean Free Air Concentration Enrichment facility under ambient (37 ppb), moderate (58 ppb), and high (116 ppb) O₃ concentrations was examined by redox-sensitive thiol labeling, mass spectrometry, and targeted enzyme assays. • Proteomic analysis of soybean leaf tissue exposed to high O₃ concentrations reveals widespread changes. In the high-O₃ treatment leaf, 35 proteins increased up to fivefold in abundance, 22 proteins showed up to fivefold higher oxidation, and 22 proteins increased in both abundance and oxidation. These changes occurred in carbon metabolism, photosynthesis, amino acid synthesis, flavonoid and isoprenoid biosynthesis, signaling and homeostasis, and antioxidant pathways. • This study shows that seasonal O₃ exposure in soybean alters the abundance and oxidation state of redox-sensitive multiple proteins and that these changes reflect a combination of damage effects and adaptive responses that influence a wide range of metabolic processes, which in some cases may help mitigate oxidative stress.
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Affiliation(s)
- Ashley Galant
- Department of Biology, Washington University, One Brookings Drive, Campus Box 1137, St. Louis, MO 63130, USA
| | - Robert P Koester
- Department of Plant Biology, 1201 West Gregory Drive, MC-051, University of Illinois, Urbana-Champaign, Urbana, IL 61801, USA
| | - Elizabeth A Ainsworth
- Department of Plant Biology, 1201 West Gregory Drive, MC-051, University of Illinois, Urbana-Champaign, Urbana, IL 61801, USA
- USDA-ARS Global Change and Photosynthesis Research Unit, 1201 West Gregory Drive, MC-051, Urbana, IL 61801, USA
| | - Leslie M Hicks
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, MO 63132, USA
| | - Joseph M Jez
- Department of Biology, Washington University, One Brookings Drive, Campus Box 1137, St. Louis, MO 63130, USA
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12
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Kim WS, Chronis D, Juergens M, Schroeder AC, Hyun SW, Jez JM, Krishnan HB. Transgenic soybean plants overexpressing O-acetylserine sulfhydrylase accumulate enhanced levels of cysteine and Bowman-Birk protease inhibitor in seeds. PLANTA 2012; 235:13-23. [PMID: 21805150 DOI: 10.1007/s00425-011-1487-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Accepted: 07/07/2011] [Indexed: 05/08/2023]
Abstract
Soybeans provide an excellent source of protein in animal feed. Soybean protein quality can be enhanced by increasing the concentration of sulfur-containing amino acids. Previous attempts to increase the concentration of sulfur-containing amino acids through the expression of heterologous proteins have met with limited success. Here, we report a successful strategy to increase the cysteine content of soybean seed through the overexpression of a key sulfur assimilatory enzyme. We have generated several transgenic soybean plants that overexpress a cytosolic isoform of O-acetylserine sulfhydrylase (OASS). These transgenic soybean plants exhibit a four- to tenfold increase in OASS activity when compared with non-transformed wild-type. The OASS activity in the transgenic soybeans was significantly higher at all the stages of seed development. Unlike the non-transformed soybean plants, there was no marked decrease in the OASS activity even at later stages of seed development. Overexpression of cytosolic OASS resulted in a 58-74% increase in protein-bound cysteine levels compared with non-transformed wild-type soybean seeds. A 22-32% increase in the free cysteine levels was also observed in transgenic soybeans overexpressing OASS. Furthermore, these transgenic soybean plants showed a marked increase in the accumulation of Bowman-Birk protease inhibitor, a cysteine-rich protein. The overall increase in soybean total cysteine content (both free and protein-bound) satisfies the recommended levels required for the optimal growth of monogastric animals.
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Affiliation(s)
- Won-Seok Kim
- Division of Plant Sciences, University of Missouri, Columbia, MO, 65211, USA
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13
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Kim WS, Chronis D, Juergens M, Schroeder AC, Hyun SW, Jez JM, Krishnan HB. Transgenic soybean plants overexpressing O-acetylserine sulfhydrylase accumulate enhanced levels of cysteine and Bowman-Birk protease inhibitor in seeds. PLANTA 2012; 235:1315-30. [PMID: 22207424 DOI: 10.1007/s00425-011-1576-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 12/13/2011] [Indexed: 05/10/2023]
Abstract
Soybeans provide an excellent source of protein in animal feed. Soybean protein quality can be enhanced by increasing the concentration of sulfur-containing amino acids. Previous attempts to increase the concentration of sulfur-containing amino acids through the expression of heterologous proteins have met with limited success. Here, we report a successful strategy to increase the cysteine content of soybean seed through the overexpression of a key sulfur assimilatory enzyme. We have generated several transgenic soybean plants that overexpress a cytosolic isoform of O-acetylserine sulfhydrylase (OASS). These transgenic soybean plants exhibit a four- to tenfold increase in OASS activity when compared with non-transformed wild-type. The OASS activity in the transgenic soybeans was significantly higher at all the stages of seed development. Unlike the non-transformed soybean plants, there was no marked decrease in the OASS activity even at later stages of seed development. Overexpression of cytosolic OASS resulted in a 58-74% increase in protein-bound cysteine levels compared with non-transformed wild-type soybean seeds. A 22-32% increase in the free cysteine levels was also observed in transgenic soybeans overexpressing OASS. Furthermore, these transgenic soybean plants showed a marked increase in the accumulation of Bowman-Birk protease inhibitor, a cysteine-rich protein. The overall increase in soybean total cysteine content (both free and protein-bound) satisfies the recommended levels required for the optimal growth of monogastric animals.
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Affiliation(s)
- Won-Seok Kim
- Division of Plant Sciences, University of Missouri, Columbia, MO, 65211, USA
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Wang Y, Yi H, Wang M, Yu O, Jez JM. Structural and kinetic analysis of the unnatural fusion protein 4-coumaroyl-CoA ligase::stilbene synthase. J Am Chem Soc 2011; 133:20684-7. [PMID: 22129213 DOI: 10.1021/ja2085993] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
To increase the biochemical efficiency of biosynthetic systems, metabolic engineers have explored different approaches for organizing enzymes, including the generation of unnatural fusion proteins. Previous work aimed at improving the biosynthesis of resveratrol, a stilbene associated a range of health-promoting activities, in yeast used an unnatural engineered fusion protein of Arabidopsis thaliana (thale cress) 4-coumaroyl-CoA ligase (At4CL1) and Vitis vinifera (grape) stilbene synthase (VvSTS) to increase resveratrol levels 15-fold relative to yeast expressing the individual enzymes. Here we present the crystallographic and biochemical analysis of the 4CL::STS fusion protein. Determination of the X-ray crystal structure of 4CL::STS provides the first molecular view of an artificial didomain adenylation/ketosynthase fusion protein. Comparison of the steady-state kinetic properties of At4CL1, VvSTS, and 4CL::STS demonstrates that the fusion protein improves catalytic efficiency of either reaction less than 3-fold. Structural and kinetic analysis suggests that colocalization of the two enzyme active sites within 70 Å of each other provides the basis for enhanced in vivo synthesis of resveratrol.
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Affiliation(s)
- Yechun Wang
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, Missouri 63132, USA
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Jez JM. Toward protein engineering for phytoremediation: possibilities and challenges. INTERNATIONAL JOURNAL OF PHYTOREMEDIATION 2011; 13 Suppl 1:77-89. [PMID: 22046752 DOI: 10.1080/15226514.2011.568537] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The combination of rational protein engineering and directed evolution techniques allow for the redesign of enzymes with tailored properties for use in environmental remediation. This review summarizes current molecular methods for either altering or improving protein function and highlights examples of how these methods can address bioremediation problems. Although much of the protein engineering applied to environmental clean-up employs microbial systems, there is great potential for and significant challenges to translating these approaches to plant systems for phytoremediation purposes. Protein engineering technologies combined with genomic information and metabolic engineering strategies hold promise for the design of plants and microbes to remediate organic and inorganic pollutants.
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Affiliation(s)
- Joseph M Jez
- Department of Biology, Washington University, St. Louis, Missouri 63130, USA.
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Yi H, Ravilious GE, Galant A, Krishnan HB, Jez JM. From sulfur to homoglutathione: thiol metabolism in soybean. Amino Acids 2010; 39:963-78. [PMID: 20364282 DOI: 10.1007/s00726-010-0572-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2009] [Accepted: 03/16/2010] [Indexed: 12/11/2022]
Abstract
Sulfur is an essential plant nutrient and is metabolized into the sulfur-containing amino acids (cysteine and methionine) and into molecules that protect plants against oxidative and environmental stresses. Although studies of thiol metabolism in the model plant Arabidopsis thaliana (thale cress) have expanded our understanding of these dynamic processes, our knowledge of how sulfur is assimilated and metabolized in crop plants, such as soybean (Glycine max), remains limited in comparison. Soybean is a major crop used worldwide for food and animal feed. Although soybeans are protein-rich, they do not contain high levels of the sulfur-containing amino acids, cysteine and methionine. Ultimately, unraveling the fundamental steps and regulation of thiol metabolism in soybean is important for optimizing crop yield and quality. Here we review the pathways from sulfur uptake to glutathione and homoglutathione synthesis in soybean, the potential biotechnology benefits of understanding and modifying these pathways, and how information from the soybean genome may guide the next steps in exploring this biochemical system.
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Affiliation(s)
- Hankuil Yi
- Department of Biology, Washington University, St. Louis, MO 63130, USA
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