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Washington EJ, Zhou Y, Hsu AL, Petrovich M, Tenor JL, Toffaletti DL, Guan Z, Perfect JR, Borgnia MJ, Bartesaghi A, Brennan RG. Structures of trehalose-6-phosphate synthase, Tps1, from the fungal pathogen Cryptococcus neoformans: A target for antifungals. Proc Natl Acad Sci U S A 2024; 121:e2314087121. [PMID: 39083421 PMCID: PMC11317593 DOI: 10.1073/pnas.2314087121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 06/25/2024] [Indexed: 08/02/2024] Open
Abstract
Invasive fungal diseases are a major threat to human health, resulting in more than 1.5 million annual deaths worldwide. The arsenal of antifungal therapeutics remains limited and is in dire need of drugs that target additional biosynthetic pathways that are absent from humans. One such pathway involves the biosynthesis of trehalose. Trehalose is a disaccharide that is required for pathogenic fungi to survive in their human hosts. In the first step of trehalose biosynthesis, trehalose-6-phosphate synthase (Tps1) converts UDP-glucose and glucose-6-phosphate to trehalose-6-phosphate. Here, we report the structures of full-length Cryptococcus neoformans Tps1 (CnTps1) in unliganded form and in complex with uridine diphosphate and glucose-6-phosphate. Comparison of these two structures reveals significant movement toward the catalytic pocket by the N terminus upon ligand binding and identifies residues required for substrate binding, as well as residues that stabilize the tetramer. Intriguingly, an intrinsically disordered domain (IDD), which is conserved among Cryptococcal species and closely related basidiomycetes, extends from each subunit of the tetramer into the "solvent" but is not visible in density maps. We determined that the IDD is not required for C. neoformans Tps1-dependent thermotolerance and osmotic stress survival. Studies with UDP-galactose highlight the exquisite substrate specificity of CnTps1. In toto, these studies expand our knowledge of trehalose biosynthesis in Cryptococcus and highlight the potential of developing antifungal therapeutics that disrupt the synthesis of this disaccharide or the formation of a functional tetramer and the use of cryo-EM in the structural characterization of CnTps1-ligand/drug complexes.
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Affiliation(s)
- Erica J. Washington
- Department of Biochemistry, Duke University School of Medicine, Durham, NC27710
| | - Ye Zhou
- Department of Computer Science, Duke University, Durham, NC27708
| | - Allen L. Hsu
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, Department of Health and Human Services, NIH, Research Triangle Park, NC27709
| | - Matthew Petrovich
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, Department of Health and Human Services, NIH, Research Triangle Park, NC27709
| | - Jennifer L. Tenor
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, NC27710
| | - Dena L. Toffaletti
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, NC27710
| | - Ziqiang Guan
- Department of Biochemistry, Duke University School of Medicine, Durham, NC27710
| | - John R. Perfect
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, NC27710
| | - Mario J. Borgnia
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, Department of Health and Human Services, NIH, Research Triangle Park, NC27709
| | - Alberto Bartesaghi
- Department of Biochemistry, Duke University School of Medicine, Durham, NC27710
- Department of Computer Science, Duke University, Durham, NC27708
| | - Richard G. Brennan
- Department of Biochemistry, Duke University School of Medicine, Durham, NC27710
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Washington EJ, Zhou Y, Hsu AL, Petrovich M, Tenor JL, Toffaletti DL, Guan Z, Perfect JR, Borgnia MJ, Bartesaghi A, Brennan RG. Structures of trehalose-6-phosphate synthase, Tps1, from the fungal pathogen Cryptococcus neoformans : a target for novel antifungals. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.03.14.530545. [PMID: 36993618 PMCID: PMC10054996 DOI: 10.1101/2023.03.14.530545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Invasive fungal diseases are a major threat to human health, resulting in more than 1.5 million annual deaths worldwide. The arsenal of antifungal therapeutics remains limited and is in dire need of novel drugs that target additional biosynthetic pathways that are absent from humans. One such pathway involves the biosynthesis of trehalose. Trehalose is a disaccharide that is required for pathogenic fungi to survive in their human hosts. In the first step of trehalose biosynthesis, trehalose-6-phosphate synthase (Tps1) converts UDP-glucose and glucose-6-phosphate to trehalose-6-phosphate. Here, we report the structures of full-length Cryptococcus neoformans Tps1 (CnTps1) in unliganded form and in complex with uridine diphosphate and glucose-6-phosphate. Comparison of these two structures reveals significant movement towards the catalytic pocket by the N-terminus upon ligand binding and identifies residues required for substrate-binding, as well as residues that stabilize the tetramer. Intriguingly, an intrinsically disordered domain (IDD), which is conserved amongst Cryptococcal species and closely related Basidiomycetes, extends from each subunit of the tetramer into the "solvent" but is not visible in density maps. We determined that the IDD is not required for C. neoformans Tps1-dependent thermotolerance and osmotic stress survival. Studies with UDP-galactose highlight the exquisite substrate specificity of CnTps1. In toto , these studies expand our knowledge of trehalose biosynthesis in Cryptococcus and highlight the potential of developing antifungal therapeutics that disrupt the synthesis of this disaccharide or the formation of a functional tetramer and the use of cryo-EM in the structural characterization of CnTps1-ligand/drug complexes. Significance Statement Fungal infections are responsible for over a million deaths worldwide each year. Biosynthesis of a disaccharide, trehalose, is required for multiple pathogenic fungi to transition from the environment to the human host. Enzymes in the trehalose biosynthesis pathway are absent in humans and, therefore, are potentially significant targets for novel antifungal therapeutics. One enzyme in the trehalose biosynthesis is trehalose-6-phosphate synthase (Tps1). Here, we describe the cryo-electron microscopy structures of the CnTps1 homo-tetramer in the unliganded form and in complex with a substrate and a product. These structures and subsequent biochemical analysis reveal key details of substrate-binding residues and substrate specificity. These structures should facilitate structure-guided design of inhibitors against CnTps1.
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Cereijo AE, Ferretti MV, Iglesias AA, Álvarez HM, Asencion Diez MD. Study of two glycosyltransferases related to polysaccharide biosynthesis in Rhodococcus jostii RHA1. Biol Chem 2024; 405:325-340. [PMID: 38487862 DOI: 10.1515/hsz-2023-0339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 02/23/2024] [Indexed: 05/04/2024]
Abstract
The bacterial genus Rhodococcus comprises organisms performing oleaginous behaviors under certain growth conditions and ratios of carbon and nitrogen availability. Rhodococci are outstanding producers of biofuel precursors, where lipid and glycogen metabolisms are closely related. Thus, a better understanding of rhodococcal carbon partitioning requires identifying catalytic steps redirecting sugar moieties to storage molecules. Here, we analyzed two GT4 glycosyl-transferases from Rhodococcus jostii (RjoGlgAb and RjoGlgAc) annotated as α-glucan-α-1,4-glucosyl transferases, putatively involved in glycogen synthesis. Both enzymes were produced in Escherichia coli cells, purified to homogeneity, and kinetically characterized. RjoGlgAb and RjoGlgAc presented the "canonical" glycogen synthase activity and were actives as maltose-1P synthases, although to a different extent. Then, RjoGlgAc is a homologous enzyme to the mycobacterial GlgM, with similar kinetic behavior and glucosyl-donor preference. RjoGlgAc was two orders of magnitude more efficient to glucosylate glucose-1P than glycogen, also using glucosamine-1P as a catalytically efficient aglycon. Instead, RjoGlgAb exhibited both activities with similar kinetic efficiency and preference for short-branched α-1,4-glucans. Curiously, RjoGlgAb presented a super-oligomeric conformation (higher than 15 subunits), representing a novel enzyme with a unique structure-to-function relationship. Kinetic results presented herein constitute a hint to infer on polysaccharides biosynthesis in rhodococci from an enzymological point of view.
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Affiliation(s)
- Antonela Estefania Cereijo
- Laboratorio de Enzimología Molecular, 603337 Instituto de Agrobiotecnología del Litoral (UNL-CONICET) & Facultad de Bioquímica y Ciencias Biológicas , Santa Fe, Argentina
| | - María Victoria Ferretti
- Laboratorio de Enzimología Molecular, 603337 Instituto de Agrobiotecnología del Litoral (UNL-CONICET) & Facultad de Bioquímica y Ciencias Biológicas , Santa Fe, Argentina
| | - Alberto Alvaro Iglesias
- Laboratorio de Enzimología Molecular, 603337 Instituto de Agrobiotecnología del Litoral (UNL-CONICET) & Facultad de Bioquímica y Ciencias Biológicas , Santa Fe, Argentina
| | - Héctor Manuel Álvarez
- Instituto de Biociencias de la Patagonia (INBIOP), 28226 Universidad Nacional de la Patagonia San Juan Bosco y CONICET , Km 4-Ciudad Universitaria 9000, Comodoro Rivadavia, Chubut, Argentina
| | - Matías Damian Asencion Diez
- Laboratorio de Enzimología Molecular, 603337 Instituto de Agrobiotecnología del Litoral (UNL-CONICET) & Facultad de Bioquímica y Ciencias Biológicas , Santa Fe, Argentina
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Cifuente JO, Colleoni C, Kalscheuer R, Guerin ME. Architecture, Function, Regulation, and Evolution of α-Glucans Metabolic Enzymes in Prokaryotes. Chem Rev 2024; 124:4863-4934. [PMID: 38606812 PMCID: PMC11046441 DOI: 10.1021/acs.chemrev.3c00811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2024]
Abstract
Bacteria have acquired sophisticated mechanisms for assembling and disassembling polysaccharides of different chemistry. α-d-Glucose homopolysaccharides, so-called α-glucans, are the most widespread polymers in nature being key components of microorganisms. Glycogen functions as an intracellular energy storage while some bacteria also produce extracellular assorted α-glucans. The classical bacterial glycogen metabolic pathway comprises the action of ADP-glucose pyrophosphorylase and glycogen synthase, whereas extracellular α-glucans are mostly related to peripheral enzymes dependent on sucrose. An alternative pathway of glycogen biosynthesis, operating via a maltose 1-phosphate polymerizing enzyme, displays an essential wiring with the trehalose metabolism to interconvert disaccharides into polysaccharides. Furthermore, some bacteria show a connection of intracellular glycogen metabolism with the genesis of extracellular capsular α-glucans, revealing a relationship between the storage and structural function of these compounds. Altogether, the current picture shows that bacteria have evolved an intricate α-glucan metabolism that ultimately relies on the evolution of a specific enzymatic machinery. The structural landscape of these enzymes exposes a limited number of core catalytic folds handling many different chemical reactions. In this Review, we present a rationale to explain how the chemical diversity of α-glucans emerged from these systems, highlighting the underlying structural evolution of the enzymes driving α-glucan bacterial metabolism.
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Affiliation(s)
- Javier O. Cifuente
- Instituto
Biofisika (UPV/EHU, CSIC), University of
the Basque Country, E-48940 Leioa, Spain
| | - Christophe Colleoni
- University
of Lille, CNRS, UMR8576-UGSF -Unité de Glycobiologie Structurale
et Fonctionnelle, F-59000 Lille, France
| | - Rainer Kalscheuer
- Institute
of Pharmaceutical Biology and Biotechnology, Heinrich Heine University, 40225 Dusseldorf, Germany
| | - Marcelo E. Guerin
- Structural
Glycobiology Laboratory, Department of Structural and Molecular Biology, Molecular Biology Institute of Barcelona (IBMB), Spanish
National Research Council (CSIC), Barcelona Science Park, c/Baldiri Reixac 4-8, Tower R, 08028 Barcelona, Catalonia, Spain
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Bhowmick S, Shenouda ML, Tschowri N. Osmotic stress responses and the biology of the second messenger c-di-AMP in Streptomyces. MICROLIFE 2023; 4:uqad020. [PMID: 37223731 PMCID: PMC10117811 DOI: 10.1093/femsml/uqad020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 03/02/2023] [Accepted: 04/10/2023] [Indexed: 05/25/2023]
Abstract
Streptomyces are prolific antibiotic producers that thrive in soil, where they encounter diverse environmental cues, including osmotic challenges caused by rainfall and drought. Despite their enormous value in the biotechnology sector, which often relies on ideal growth conditions, how Streptomyces react and adapt to osmotic stress is heavily understudied. This is likely due to their complex developmental biology and an exceptionally broad number of signal transduction systems. With this review, we provide an overview of Streptomyces' responses to osmotic stress signals and draw attention to open questions in this research area. We discuss putative osmolyte transport systems that are likely involved in ion balance control and osmoadaptation and the role of alternative sigma factors and two-component systems (TCS) in osmoregulation. Finally, we highlight the current view on the role of the second messenger c-di-AMP in cell differentiation and the osmotic stress responses with specific emphasis on the two models, S. coelicolor and S. venezuelae.
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Affiliation(s)
- Sukanya Bhowmick
- Institute of Microbiology, Leibniz Universität Hannover, 30419 Hannover, Germany
| | - Mary L Shenouda
- Institute of Microbiology, Leibniz Universität Hannover, 30419 Hannover, Germany
| | - Natalia Tschowri
- Corresponding author. Institute of Microbiology, Leibniz Universität Hannover, 30419 Hannover, Germany. E-mail:
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Bhayani J, Iglesias MJ, Minen RI, Cereijo AE, Ballicora MA, Iglesias AA, Asencion Diez MD. Carbohydrate Metabolism in Bacteria: Alternative Specificities in ADP-Glucose Pyrophosphorylases Open Novel Metabolic Scenarios and Biotechnological Tools. Front Microbiol 2022; 13:867384. [PMID: 35572620 PMCID: PMC9093745 DOI: 10.3389/fmicb.2022.867384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 03/22/2022] [Indexed: 11/13/2022] Open
Abstract
We explored the ability of ADP-glucose pyrophosphorylase (ADP-Glc PPase) from different bacteria to use glucosamine (GlcN) metabolites as a substrate or allosteric effectors. The enzyme from the actinobacteria Kocuria rhizophila exhibited marked and distinctive sensitivity to allosteric activation by GlcN-6P when producing ADP-Glc from glucose-1-phosphate (Glc-1P) and ATP. This behavior is also seen in the enzyme from Rhodococcus spp., the only one known so far to portray this activation. GlcN-6P had a more modest effect on the enzyme from other Actinobacteria (Streptomyces coelicolor), Firmicutes (Ruminococcus albus), and Proteobacteria (Agrobacterium tumefaciens) groups. In addition, we studied the catalytic capacity of ADP-Glc PPases from the different sources using GlcN-1P as a substrate when assayed in the presence of their respective allosteric activators. In all cases, the catalytic efficiency of Glc-1P was 1-2 orders of magnitude higher than GlcN-1P, except for the unregulated heterotetrameric protein (GlgC/GgD) from Geobacillus stearothermophilus. The Glc-1P substrate preference is explained using a model of ADP-Glc PPase from A. tumefaciens based on the crystallographic structure of the enzyme from potato tuber. The substrate-binding domain localizes near the N-terminal of an α-helix, which has a partial positive charge, thus favoring the interaction with a hydroxyl rather than a charged primary amine group. Results support the scenario where the ability of ADP-Glc PPases to use GlcN-1P as an alternative occurred during evolution despite the enzyme being selected to use Glc-1P and ATP for α-glucans synthesis. As an associated consequence in such a process, certain bacteria could have improved their ability to metabolize GlcN. The work also provides insights in designing molecular tools for producing oligo and polysaccharides with amino moieties.
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Affiliation(s)
- Jaina Bhayani
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, IL, United States
| | - Maria Josefina Iglesias
- Facultad de Bioquímica y Ciencias Biológicas, Instituto de Agrobiotecnología del Litoral, Universidad Nacional del Litoral, Consejo Nacional de Investigaciones Científicas y Técnicas, Santa Fe, Argentina
| | - Romina I. Minen
- Facultad de Bioquímica y Ciencias Biológicas, Instituto de Agrobiotecnología del Litoral, Universidad Nacional del Litoral, Consejo Nacional de Investigaciones Científicas y Técnicas, Santa Fe, Argentina
| | - Antonela E. Cereijo
- Facultad de Bioquímica y Ciencias Biológicas, Instituto de Agrobiotecnología del Litoral, Universidad Nacional del Litoral, Consejo Nacional de Investigaciones Científicas y Técnicas, Santa Fe, Argentina
| | - Miguel A. Ballicora
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, IL, United States
| | - Alberto A. Iglesias
- Facultad de Bioquímica y Ciencias Biológicas, Instituto de Agrobiotecnología del Litoral, Universidad Nacional del Litoral, Consejo Nacional de Investigaciones Científicas y Técnicas, Santa Fe, Argentina
| | - Matias D. Asencion Diez
- Facultad de Bioquímica y Ciencias Biológicas, Instituto de Agrobiotecnología del Litoral, Universidad Nacional del Litoral, Consejo Nacional de Investigaciones Científicas y Técnicas, Santa Fe, Argentina
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Sueda R, Yoshida K, Onodera M, Fukui T, Yatsunami R, Nakamura S. Characterization of a GlgC homolog from extremely halophilic archaeon Haloarcula japonica. Biosci Biotechnol Biochem 2021; 85:1441-1447. [PMID: 33749776 DOI: 10.1093/bbb/zbab050] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Accepted: 03/16/2021] [Indexed: 11/12/2022]
Abstract
Glycogen synthesis in bacteria is mainly organized by the products of glgB, glgC, and glgA genes comprising the widely known glg operon. On the genome of extremely halophilic archaeon Haloarcula japonica, there was a gene cluster analogous to the bacterial glg operon. In this study, we focused on a GlgC homolog of Ha. japonica, and its recombinant enzyme was prepared and characterized. The enzyme showed highest activity toward GTP and glucose-1-phosphate as substrates in the presence of 2.6 m KCl and predicted to be work as "GDP-glucose pyrophosphorylase" in Ha. japonica.
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Affiliation(s)
- Rin Sueda
- School of Life Science and Technology, Tokyo Institute of Technology, Midori-ku, Yokohama, Japan
| | - Kento Yoshida
- School of Life Science and Technology, Tokyo Institute of Technology, Midori-ku, Yokohama, Japan
| | - Masahiko Onodera
- School of Life Science and Technology, Tokyo Institute of Technology, Midori-ku, Yokohama, Japan
| | - Toshiaki Fukui
- School of Life Science and Technology, Tokyo Institute of Technology, Midori-ku, Yokohama, Japan
| | - Rie Yatsunami
- School of Life Science and Technology, Tokyo Institute of Technology, Midori-ku, Yokohama, Japan
| | - Satoshi Nakamura
- School of Life Science and Technology, Tokyo Institute of Technology, Midori-ku, Yokohama, Japan.,National Institute of Technology, Numazu College, Numazu, Shizuoka, Japan
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Figueroa CM, Lunn JE, Iglesias AA. Nucleotide-sugar metabolism in plants: the legacy of Luis F. Leloir. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:4053-4067. [PMID: 33948638 DOI: 10.1093/jxb/erab109] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 04/09/2021] [Indexed: 06/12/2023]
Abstract
This review commemorates the 50th anniversary of the Nobel Prize in Chemistry awarded to Luis F. Leloir 'for his discovery of sugar-nucleotides and their role in the biosynthesis of carbohydrates'. He and his co-workers discovered that activated forms of simple sugars, such as UDP-glucose and UDP-galactose, are essential intermediates in the interconversion of sugars. They elucidated the biosynthetic pathways for sucrose and starch, which are the major end-products of photosynthesis, and for trehalose. Trehalose 6-phosphate, the intermediate of trehalose biosynthesis that they discovered, is now a molecule of great interest due to its function as a sugar signalling metabolite that regulates many aspects of plant metabolism and development. The work of the Leloir group also opened the doors to an understanding of the biosynthesis of cellulose and other structural cell wall polysaccharides (hemicelluloses and pectins), and ascorbic acid (vitamin C). Nucleotide-sugars also serve as sugar donors for a myriad of glycosyltransferases that conjugate sugars to other molecules, including lipids, phytohormones, secondary metabolites, and proteins, thereby modifying their biological activity. In this review, we highlight the diversity of nucleotide-sugars and their functions in plants, in recognition of Leloir's rich and enduring legacy to plant science.
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Affiliation(s)
- Carlos M Figueroa
- Instituto de Agrobiotecnología del Litoral, UNL, CONICET, FBCB, Colectora Ruta Nacional 168 km 0, 3000 Santa Fe,Argentina
| | - John E Lunn
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Alberto A Iglesias
- Instituto de Agrobiotecnología del Litoral, UNL, CONICET, FBCB, Colectora Ruta Nacional 168 km 0, 3000 Santa Fe,Argentina
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Cereijo AE, Kuhn ML, Hernández MA, Ballicora MA, Iglesias AA, Alvarez HM, Asencion Diez MD. Study of duplicated galU genes in Rhodococcus jostii and a putative new metabolic node for glucosamine-1P in rhodococci. Biochim Biophys Acta Gen Subj 2020; 1865:129727. [PMID: 32890704 DOI: 10.1016/j.bbagen.2020.129727] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 08/11/2020] [Accepted: 08/30/2020] [Indexed: 01/10/2023]
Abstract
BACKGOUND Studying enzymes that determine glucose-1P fate in carbohydrate metabolism is important to better understand microorganisms as biotechnological tools. One example ripe for discovery is the UDP-glucose pyrophosphorylase enzyme from Rhodococcus spp. In the R. jostii genome, this gene is duplicated, whereas R. fascians contains only one copy. METHODS We report the molecular cloning of galU genes from R. jostii and R. fascians to produce recombinant proteins RjoGalU1, RjoGalU2, and RfaGalU. Substrate saturation curves were conducted, kinetic parameters were obtained and the catalytic efficiency (kcat/Km) was used to analyze enzyme promiscuity. We also investigated the response of R. jostii GlmU pyrophosphorylase activity with different sugar-1Ps, which may compete for substrates with RjoGalU2. RESULTS All enzymes were active as pyrophosphorylases and exhibited substrate promiscuity toward sugar-1Ps. Remarkably, RjoGalU2 exhibited one order of magnitude higher activity with glucosamine-1P than glucose-1P, the canonical substrate. Glucosamine-1P activity was also significant in RfaGalU. The efficient use of the phospho-amino-sugar suggests the feasibility of the reaction to occur in vivo. Also, RjoGalU2 and RfaGalU represent enzymatic tools for the production of (amino)glucosyl precursors for the putative synthesis of novel molecules. CONCLUSIONS Results support the hypothesis that partitioning of glucosamine-1P includes an uncharacterized metabolic node in Rhodococcus spp., which could be important for producing diverse alternatives for carbohydrate metabolism in biotechnological applications. GENERAL SIGNIFICANCE Results presented here provide a model to study evolutionary enzyme promiscuity, which could be used as a tool to expand an organism's metabolic repertoire by incorporating non-canonical substrates into novel metabolic pathways.
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Affiliation(s)
- A E Cereijo
- Instituto de Agrobiotecnología del Litoral (UNL-CONICET), Facultad de Bioquímica y Ciencias Biológicas, CCT-Santa Fe, Colectora Ruta Nac 168 km 0, 3000 Santa Fe, Argentina
| | - M L Kuhn
- Department of Chemistry and Biochemistry, San Francisco State University, 1600 Holloway Ave., San Francisco, CA, United States
| | - M A Hernández
- Instituto de Biociencias de la Patagonia (INBIOP), Universidad Nacional de la Patagonia San Juan Bosco y CONICET, Km 4-Ciudad Universitaria 9000, Comodoro Rivadavia, Chubut, Argentina
| | - M A Ballicora
- Department of Chemistry and Biochemistry, Loyola University Chicago, 1068 W. Sheridan Rd., Chicago, IL 60660, United States
| | - A A Iglesias
- Instituto de Agrobiotecnología del Litoral (UNL-CONICET), Facultad de Bioquímica y Ciencias Biológicas, CCT-Santa Fe, Colectora Ruta Nac 168 km 0, 3000 Santa Fe, Argentina
| | - H M Alvarez
- Instituto de Biociencias de la Patagonia (INBIOP), Universidad Nacional de la Patagonia San Juan Bosco y CONICET, Km 4-Ciudad Universitaria 9000, Comodoro Rivadavia, Chubut, Argentina.
| | - M D Asencion Diez
- Instituto de Agrobiotecnología del Litoral (UNL-CONICET), Facultad de Bioquímica y Ciencias Biológicas, CCT-Santa Fe, Colectora Ruta Nac 168 km 0, 3000 Santa Fe, Argentina.
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10
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Crystal structures of Magnaporthe oryzae trehalose-6-phosphate synthase (MoTps1) suggest a model for catalytic process of Tps1. Biochem J 2020; 476:3227-3240. [PMID: 31455720 DOI: 10.1042/bcj20190289] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 08/22/2019] [Accepted: 08/27/2019] [Indexed: 11/17/2022]
Abstract
Trehalose-6-phosphate (T6P) synthase (Tps1) catalyzes the formation of T6P from UDP-glucose (UDPG) (or GDPG, etc.) and glucose-6-phosphate (G6P), and structural basis of this process has not been well studied. MoTps1 (Magnaporthe oryzae Tps1) plays a critical role in carbon and nitrogen metabolism, but its structural information is unknown. Here we present the crystal structures of MoTps1 apo, binary (with UDPG) and ternary (with UDPG/G6P or UDP/T6P) complexes. MoTps1 consists of two modified Rossmann-fold domains and a catalytic center in-between. Unlike Escherichia coli OtsA (EcOtsA, the Tps1 of E. coli), MoTps1 exists as a mixture of monomer, dimer, and oligomer in solution. Inter-chain salt bridges, which are not fully conserved in EcOtsA, play primary roles in MoTps1 oligomerization. Binding of UDPG by MoTps1 C-terminal domain modifies the substrate pocket of MoTps1. In the MoTps1 ternary complex structure, UDP and T6P, the products of UDPG and G6P, are detected, and substantial conformational rearrangements of N-terminal domain, including structural reshuffling (β3-β4 loop to α0 helix) and movement of a 'shift region' towards the catalytic centre, are observed. These conformational changes render MoTps1 to a 'closed' state compared with its 'open' state in apo or UDPG complex structures. By solving the EcOtsA apo structure, we confirmed that similar ligand binding induced conformational changes also exist in EcOtsA, although no structural reshuffling involved. Based on our research and previous studies, we present a model for the catalytic process of Tps1. Our research provides novel information on MoTps1, Tps1 family, and structure-based antifungal drug design.
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Mycobacterial OtsA Structures Unveil Substrate Preference Mechanism and Allosteric Regulation by 2-Oxoglutarate and 2-Phosphoglycerate. mBio 2019; 10:mBio.02272-19. [PMID: 31772052 PMCID: PMC6879718 DOI: 10.1128/mbio.02272-19] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Mycobacterial infections are a significant source of mortality worldwide, causing millions of deaths annually. Trehalose is a multipurpose disaccharide that plays a fundamental structural role in these organisms as a component of mycolic acids, a molecular hallmark of the cell envelope of mycobacteria. Here, we describe the first mycobacterial OtsA structures. We show mechanisms of substrate preference and show that OtsA is regulated allosterically by 2-oxoglutarate and 2-phosphoglycerate at an interfacial site. These results identify a new allosteric site and provide insight on the regulation of trehalose synthesis through the OtsAB pathway in mycobacteria. Trehalose is an essential disaccharide for mycobacteria and a key constituent of several cell wall glycolipids with fundamental roles in pathogenesis. Mycobacteria possess two pathways for trehalose biosynthesis. However, only the OtsAB pathway was found to be essential in Mycobacterium tuberculosis, with marked growth and virulence defects of OtsA mutants and strict essentiality of OtsB2. Here, we report the first mycobacterial OtsA structures from Mycobacterium thermoresistibile in both apo and ligand-bound forms. Structural information reveals three key residues in the mechanism of substrate preference that were further confirmed by site-directed mutagenesis. Additionally, we identify 2-oxoglutarate and 2-phosphoglycerate as allosteric regulators of OtsA. The structural analysis in this work strongly contributed to define the mechanisms for feedback inhibition, show different conformational states of the enzyme, and map a new allosteric site.
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Claeys H, Vi SL, Xu X, Satoh-Nagasawa N, Eveland AL, Goldshmidt A, Feil R, Beggs GA, Sakai H, Brennan RG, Lunn JE, Jackson D. Control of meristem determinacy by trehalose 6-phosphate phosphatases is uncoupled from enzymatic activity. NATURE PLANTS 2019; 5:352-357. [PMID: 30936436 PMCID: PMC7444751 DOI: 10.1038/s41477-019-0394-z] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 02/26/2019] [Indexed: 05/18/2023]
Abstract
Meristem fate is regulated by trehalose 6-phosphate phosphatases (TPPs), but their mechanism of action remains mysterious. Loss of the maize TPPs RAMOSA3 and TPP4 leads to reduced meristem determinacy and more inflorescence branching. However, analysis of an allelic series revealed no correlation between enzymatic activity and branching, and a catalytically inactive version of RA3 complements the ra3 mutant. Together with their nuclear localization, these findings suggest a moonlighting function for TPPs.
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Affiliation(s)
- Hannes Claeys
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY, USA
| | - Son Lang Vi
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY, USA
- Agricultural Genetics Institute, Hanoi, Vietnam
| | - Xiaosa Xu
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY, USA
| | - Namiko Satoh-Nagasawa
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY, USA
- DuPont Pioneer, Wilmington, DE, USA
- Akita Prefectural University, Akita, Japan
| | | | - Alexander Goldshmidt
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY, USA
- Institute of Plant Sciences, Agricultural Research Organization, Volcani Center, Bet Dagan, Israel
| | - Regina Feil
- Max Planck Institute of Molecular Plant Physiology, Potsdam, Germany
| | | | - Hajime Sakai
- DuPont Pioneer, Wilmington, DE, USA
- Napigen, Wilmington, DE, USA
| | | | - John E Lunn
- Max Planck Institute of Molecular Plant Physiology, Potsdam, Germany
| | - David Jackson
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY, USA.
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