1
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Pyle JD, Lund SR, O'Toole KH, Saleh L. Virus-encoded glycosyltransferases hypermodify DNA with diverse glycans. Cell Rep 2024; 43:114631. [PMID: 39154342 DOI: 10.1016/j.celrep.2024.114631] [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: 02/01/2024] [Revised: 07/08/2024] [Accepted: 07/30/2024] [Indexed: 08/20/2024] Open
Abstract
Enzymatic modification of DNA nucleobases can coordinate gene expression, nuclease protection, or mutagenesis. We recently discovered a clade of phage-specific cytosine methyltransferase (MT) and 5-methylpyrimidine dioxygenase (5mYOX) enzymes that produce 5-hydroxymethylcytosine (5hmC) as a precursor for enzymatic hypermodifications on viral genomes. Here, we identify phage MT- and 5mYOX-associated glycosyltransferases (GTs) that catalyze linkage of diverse sugars to 5hmC nucleobase substrates. Metavirome mining revealed thousands of biosynthetic gene clusters containing enzymes with predicted roles in cytosine sugar hypermodification. We developed a platform for high-throughput screening of GT-containing pathways, relying on the Escherichia coli metabolome as a substrate pool. We successfully reconstituted several pathways and isolated diverse sugar modifications appended to cytosine, including mono-, di-, or tri-saccharides comprised of hexoses, N-acetylhexosamines, or heptose. These findings expand our knowledge of hypermodifications on nucleic acids and the origins of corresponding sugar-installing enzymes.
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Affiliation(s)
- Jesse D Pyle
- Research Department, New England Biolabs, 240 County Road, Ipswich, MA 01938, USA
| | - Sean R Lund
- Research Department, New England Biolabs, 240 County Road, Ipswich, MA 01938, USA
| | - Katherine H O'Toole
- Research Department, New England Biolabs, 240 County Road, Ipswich, MA 01938, USA
| | - Lana Saleh
- Research Department, New England Biolabs, 240 County Road, Ipswich, MA 01938, USA.
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2
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Xu S, Zhao J, Liu X, Yang X, Xu Z, Gao Y, Ma Y, Yang H. Structures of SenB and SenA enzymes from Variovorax paradoxus provide insights into carbon-selenium bond formation in selenoneine biosynthesis. Heliyon 2024; 10:e32888. [PMID: 38994077 PMCID: PMC11237966 DOI: 10.1016/j.heliyon.2024.e32888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 06/10/2024] [Accepted: 06/11/2024] [Indexed: 07/13/2024] Open
Abstract
Selenoneine, an ergothioneine analog, is important for antioxidation and detoxification. SenB and SenA are two crucial enzymes that form carbon-selenium bonds in the selenoneine biosynthetic pathway. To investigate their underlying catalytic mechanisms, we obtained complex structures of SenB with its substrate UDP-N-acetylglucosamine (UDP-GlcNAc) and SenA with N-α-trimethyl histidine (TMH). SenB adopts a type-B glycosyltransferase fold. Structural and functional analysis of the interaction network at the active center provide key information on substrate recognition and suggest a metal-ion-independent, inverting mechanism is utilized for SenB-mediated selenoglycoside formation. Moreover, the complex structure of SenA with TMH and enzymatic activity assays highlight vital residues that control substrate binding and specificity. Based on the conserved structure and substrate-binding pocket of the type I sulfoxide synthase EgtB in the ergothioneine biosynthetic pathway, a similar reaction mechanism was proposed for the formation of C-Se bonds by SenA. The structures provide knowledge on selenoneine synthesis and lay groundwork for further applications of this pathway.
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Affiliation(s)
- Sihan Xu
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Jinyi Zhao
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Xiang Liu
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Center for Cell Response, College of Life Sciences, College of Pharmacy, Nankai University, Tianjin, China
| | - Xiuna Yang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Zili Xu
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Yan Gao
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Yuanyuan Ma
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Haitao Yang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
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3
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Remmerswaal WA, de Jong T, van de Vrande KNA, Louwersheimer R, Verwaal T, Filippov DV, Codée JDC, Hansen T. Backside versus Frontside S N2 Reactions of Alkyl Triflates and Alcohols. Chemistry 2024; 30:e202400590. [PMID: 38385647 DOI: 10.1002/chem.202400590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Accepted: 02/22/2024] [Indexed: 02/23/2024]
Abstract
Nucleophilic substitution reactions are elementary reactions in organic chemistry that are used in many synthetic routes. By quantum chemical methods, we have investigated the intrinsic competition between the backside SN2 (SN2-b) and frontside SN2 (SN2-f) pathways using a set of simple alkyl triflates as the electrophile in combination with a systematic series of phenols and partially fluorinated ethanol nucleophiles. It is revealed how and why the well-established mechanistic preference for the SN2-b pathway slowly erodes and can even be overruled by the unusual SN2-f substitution mechanism going from strong to weak alcohol nucleophiles. Activation strain analyses disclose that the SN2-b pathway is favored for strong alcohol nucleophiles because of the well-known intrinsically more efficient approach to the electrophile resulting in a more stabilizing nucleophile-electrophile interaction. In contrast, the preference of weaker alcohol nucleophiles shifts to the SN2-f pathway, benefiting from a stabilizing hydrogen bond interaction between the incoming alcohol and the leaving group. This hydrogen bond interaction is strengthened by the increased acidity of the weaker alcohol nucleophiles, thereby steering the mechanistic preference toward the frontside SN2 pathway.
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Affiliation(s)
- Wouter A Remmerswaal
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The, Netherlands
| | - Tjeerd de Jong
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The, Netherlands
| | - Koen N A van de Vrande
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The, Netherlands
| | - Rick Louwersheimer
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The, Netherlands
| | - Thomas Verwaal
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The, Netherlands
| | - Dmitri V Filippov
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The, Netherlands
| | - Jeroen D C Codée
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The, Netherlands
| | - Thomas Hansen
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The, Netherlands
- Department of Chemistry and Pharmaceutical Sciences, AIMMS, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ, Amsterdam, The, Netherlands
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4
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Hassan BA, Milicaj J, Tyson M, Karki R, Sham YY, Frantom PA, Taylor EA. In Vitro and In Silico Explorations of the Protein Conformational Changes of Corynebacterium glutamicum MshA, a Model Retaining GT-B Glycosyltransferase. Biochemistry 2024; 63:939-951. [PMID: 38507812 DOI: 10.1021/acs.biochem.3c00561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
MshA is a GT-B glycosyltransferase catalyzing the first step in the biosynthesis of mycothiol. While many GT-B enzymes undergo an open-to-closed transition, MshA is unique because its 97° rotation is beyond the usual range of 10-25°. Molecular dynamics (MD) simulations were carried out for MshA in both ligand bound and unbound states to investigate the effect of ligand binding on localized protein dynamics and its conformational free energy landscape. Simulations showed that both the unliganded "opened" and liganded "closed" forms of the enzyme sample a wide degree of dihedral angles and interdomain distances with relatively low overlapping populations. Calculation of the free energy surface using replica exchange MD for the apo "opened" and an artificial generated apo "closed" structure revealed overlaps in the geometries sampled, allowing calculation of a barrier of 2 kcal/mol for the open-to-closed transition in the absence of ligands. MD simulations of fully liganded MshA revealed a smaller sampling of the dihedral angles. The localized protein fluctuation changes suggest that UDP-GlcNAc binding activates the motions of loops in the 1-l-myo-inositol-1-phosphate (I1P)-binding site despite little change in the interactions with UDP-GlcNAc. Circular dichroism, intrinsic fluorescence spectroscopy, and mutagenesis studies were used to confirm the ligand-induced structural changes in MshA. The results support a proposed mechanism where UDP-GlcNAc binds with rigid interactions to the C-terminal domain of MshA and activates flexible loops in the N-terminal domain for binding and positioning of I1P. This model can be used for future structure-based drug development of inhibitors of the mycothiol biosynthetic pathway.
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Affiliation(s)
- Bakar A Hassan
- Department of Chemistry, Wesleyan University, Middletown, Connecticut 06459, United States
| | - Jozafina Milicaj
- Department of Chemistry, Wesleyan University, Middletown, Connecticut 06459, United States
| | - Meka Tyson
- Department of Chemistry, Wesleyan University, Middletown, Connecticut 06459, United States
| | - Ramesh Karki
- Department of Chemistry & Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Yuk Y Sham
- Bioinformatics and Computational Biology Program, University of Minnesota, Minneapolis, Minnesota 55455, United States
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Patrick A Frantom
- Department of Chemistry & Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Erika A Taylor
- Department of Chemistry, Wesleyan University, Middletown, Connecticut 06459, United States
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5
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Alshareef SA. Metabolic analysis of the CAZy class glycosyltransferases in rhizospheric soil fungiome of the plant species Moringa oleifera. Saudi J Biol Sci 2024; 31:103956. [PMID: 38404538 PMCID: PMC10891331 DOI: 10.1016/j.sjbs.2024.103956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Revised: 02/03/2024] [Accepted: 02/10/2024] [Indexed: 02/27/2024] Open
Abstract
The target of the present work is to study the most abundant carbohydrate-active enzymes (CAZymes) of glycosyltransferase (GT) class, which are encoded by fungiome genes present in the rhizospheric soil of the plant species Moringa oleifera. The datasets of this CAZy class were recovered using metagenomic whole shotgun genome sequencing approach, and the resultant CAZymes were searched against the KEGG pathway database to identify function. High emphasis was given to the two GT families, GT4 and GT2, which were the highest within GT class in the number and abundance of gene queries in this soil compartment. These two GT families harbor CAZymes playing crucial roles in cell membrane and cell wall processes. These CAZymes are responsible for synthesizing essential structural components such as cellulose and chitin, which contribute to the integrity of cell walls in plants and fungi. The CAZyme beta-1,3-glucan synthase of GT2 family accumulates 1,3-β-glucan, which provides elasticity as well as tensile strength to the fungal cell wall. Other GT CAZymes contribute to the biosynthesis of several compounds crucial for cell membrane and wall integrity, including lipopolysaccharide, e.g., lipopolysaccharide N-acetylglucosaminyltransferase, cell wall teichoic acid, e.g., alpha-glucosyltransferase, and cellulose, e.g., cellulose synthase. These compounds also play pivotal roles in ion homeostasis, organic carbon mineralization, and osmoprotection against abiotic stresses in plants. This study emphasizes the major roles of these two CAZy GT families in connecting the structure and function of cell membranes and cell walls of fungal and plant cells. The study also sheds light on the potential occurrence of tripartite symbiotic relationships involving the plant, rhizospheric bacteriome, and fungiome via the action of CAZymes of GT4 and GT2 families. These findings provide valuable insights towards the generation of innovative agricultural practices to enhance the performance of crop plants in the future.
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Affiliation(s)
- Sahar A. Alshareef
- Department of Biology, College of Science and Arts at Khulis, University of Jeddah, Jeddah, Saudi Arabia
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6
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Bhattacharje G, Ghosh A, Das AK. Deciphering the mannose transfer mechanism of mycobacterial PimE by molecular dynamics simulations. Glycobiology 2024; 34:cwad096. [PMID: 38039077 DOI: 10.1093/glycob/cwad096] [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: 10/04/2023] [Revised: 11/21/2023] [Accepted: 11/27/2023] [Indexed: 12/03/2023] Open
Abstract
Phosphatidyl-myo-inositol mannosides (PIMs), Lipomannan (LM), and Lipoarabinomannan (LAM) are essential components of the cell envelopes of mycobacteria. At the beginning of the biosynthesis of these compounds, phosphatidylinositol (PI) is mannosylated and acylated by various enzymes to produce Ac1/2PIM4, which is used to synthesize either Ac1/2PIM6 or LM/LAM. The protein PimE, a membrane-bound glycosyltransferase (GT-C), catalyzes the addition of a mannose group to Ac1PIM4 to produce Ac1PIM5, using polyprenolphosphate mannose (PPM) as the mannose donor. PimE-deleted Mycobacterium smegmatis (Msmeg) showed structural deformity and increased antibiotic and copper sensitivity. Despite knowing that the mutation D58A caused inactivity in Msmeg, how PimE catalyzes the transfer of mannose from PPM to Ac1/2PIM4 remains unknown. In this study, analyzing the AlphaFold structure of PimE revealed the presence of a tunnel through the D58 residue with two differently charged gates. Molecular docking suggested PPM binds to the hydrophobic tunnel gate, whereas Ac1PIM4 binds to the positively charged tunnel gate. Molecular dynamics (MD) simulations further demonstrated the critical roles of the residues N55, F87, L89, Y163, Q165, K197, L198, R251, F277, W324, H326, and I375 in binding PPM and Ac1PIM4. The mutation D58A caused a faster release of PPM from the catalytic tunnel, explaining the loss of PimE activity. Along with a hypothetical mechanism of mannose transfer by PimE, we also observe the presence of tunnels through a negatively charged aspartate or glutamate with two differently-charged gates among most GT-C enzymes. Common hydrophobic gates of GT-C enzymes probably harbor sugar donors, whereas, differently-charged tunnel gates accommodate various sugar-acceptors.
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Affiliation(s)
- Gourab Bhattacharje
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, West Midnapore, WB 721302, India
| | - Amit Ghosh
- School of Energy Science and Engineering, Indian Institute of Technology Kharagpur, Kharagpur, West Midnapore, WB 721302, India
| | - Amit Kumar Das
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, West Midnapore, WB 721302, India
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7
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Siebert D, Glawischnig E, Wirth MT, Vannahme M, Salazar-Quirós Á, Weiske A, Saydam E, Möggenried D, Wendisch VF, Blombach B. A genome-reduced Corynebacterium glutamicum derivative discloses a hidden pathway relevant for 1,2-propanediol production. Microb Cell Fact 2024; 23:62. [PMID: 38402147 PMCID: PMC10893638 DOI: 10.1186/s12934-024-02337-w] [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: 12/19/2023] [Accepted: 02/16/2024] [Indexed: 02/26/2024] Open
Abstract
BACKGROUND 1,2-propanediol (1,2-PDO) is widely used in the cosmetic, food, and drug industries with a worldwide consumption of over 1.5 million metric tons per year. Although efforts have been made to engineer microbial hosts such as Corynebacterium glutamicum to produce 1,2-PDO from renewable resources, the performance of such strains is still improvable to be competitive with existing petrochemical production routes. RESULTS In this study, we enabled 1,2-PDO production in the genome-reduced strain C. glutamicum PC2 by introducing previously described modifications. The resulting strain showed reduced product formation but secreted 50 ± 1 mM D-lactate as byproduct. C. glutamicum PC2 lacks the D-lactate dehydrogenase which pointed to a yet unknown pathway relevant for 1,2-PDO production. Further analysis indicated that in C. glutamicum methylglyoxal, the precursor for 1,2-PDO synthesis, is detoxified with the antioxidant native mycothiol (MSH) by a glyoxalase-like system to lactoylmycothiol and converted to D-lactate which is rerouted into the central carbon metabolism at the level of pyruvate. Metabolomics of cell extracts of the empty vector-carrying wildtype, a 1,2-PDO producer and its derivative with inactive D-lactate dehydrogenase identified major mass peaks characteristic for lactoylmycothiol and its precursors MSH and glucosaminyl-myo-inositol, whereas the respective mass peaks were absent in a production strain with inactivated MSH synthesis. Deletion of mshA, encoding MSH synthase, in the 1,2-PDO producing strain C. glutamicum ΔhdpAΔldh(pEKEx3-mgsA-yqhD-gldA) improved the product yield by 56% to 0.53 ± 0.01 mM1,2-PDO mMglucose-1 which is the highest value for C. glutamicum reported so far. CONCLUSIONS Genome reduced-strains are a useful basis to unravel metabolic constraints for strain engineering and disclosed in this study the pathway to detoxify methylglyoxal which represents a precursor for 1,2-PDO production. Subsequent inactivation of the competing pathway significantly improved the 1,2-PDO yield.
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Affiliation(s)
- Daniel Siebert
- Microbial Biotechnology, Campus Straubing for Biotechnology and Sustainability, Technical University of Munich, Straubing, Germany
- SynBiofoundry@TUM, Technical University of Munich, Straubing, Germany
- Chair of Genetics of Prokaryotes, Faculty of Biology & CeBiTec, Bielefeld University, Bielefeld, Germany
| | - Erich Glawischnig
- Microbial Biotechnology, Campus Straubing for Biotechnology and Sustainability, Technical University of Munich, Straubing, Germany
- SynBiofoundry@TUM, Technical University of Munich, Straubing, Germany
| | - Marie-Theres Wirth
- Microbial Biotechnology, Campus Straubing for Biotechnology and Sustainability, Technical University of Munich, Straubing, Germany
| | - Mieke Vannahme
- Microbial Biotechnology, Campus Straubing for Biotechnology and Sustainability, Technical University of Munich, Straubing, Germany
| | - Álvaro Salazar-Quirós
- Microbial Biotechnology, Campus Straubing for Biotechnology and Sustainability, Technical University of Munich, Straubing, Germany
| | - Annette Weiske
- Microbial Biotechnology, Campus Straubing for Biotechnology and Sustainability, Technical University of Munich, Straubing, Germany
| | - Ezgi Saydam
- Microbial Biotechnology, Campus Straubing for Biotechnology and Sustainability, Technical University of Munich, Straubing, Germany
| | - Dominik Möggenried
- Microbial Biotechnology, Campus Straubing for Biotechnology and Sustainability, Technical University of Munich, Straubing, Germany
| | - Volker F Wendisch
- Chair of Genetics of Prokaryotes, Faculty of Biology & CeBiTec, Bielefeld University, Bielefeld, Germany
| | - Bastian Blombach
- Microbial Biotechnology, Campus Straubing for Biotechnology and Sustainability, Technical University of Munich, Straubing, Germany.
- SynBiofoundry@TUM, Technical University of Munich, Straubing, Germany.
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8
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Ireland K, Kayrouz CM, Huang J, Seyedsayamdost MR, Davis KM. Structural Characterization and Ligand-Induced Conformational Changes of SenB, a Se-Glycosyltransferase Involved in Selenoneine Biosynthesis. Biochemistry 2023; 62:3337-3342. [PMID: 37966244 PMCID: PMC10702425 DOI: 10.1021/acs.biochem.3c00452] [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] [Received: 08/26/2023] [Revised: 11/07/2023] [Accepted: 11/07/2023] [Indexed: 11/16/2023]
Abstract
Selenium (Se) is an essential micronutrient that is found naturally in proteins, nucleic acids, and natural products. Unlike selenoproteins and selenonucleic acids, little is known about the structures of biosynthetic enzymes that incorporate Se into small molecules. Here, we report the X-ray crystal structure of SenB, the first known Se-glycosyltransferase that was recently found to be involved in the biosynthesis of the Se-containing metabolite selenoneine. SenB catalyzes C-Se bond formation using selenophosphate and an activated uridine diphosphate sugar as a Se and glycosyl donor, respectively, making it the first known selenosugar synthase and one of only four bona fide C-Se bond-forming enzymes discovered to date. Our crystal structure, determined to 2.25 Å resolution, reveals that SenB is a type B glycosyltransferase, displaying the prototypical fold with two globular Rossmann-like domains and a catalytic interdomain cleft. By employing complementary structural biology techniques, we find that SenB undergoes both local and global substrate-induced conformational changes, demonstrating a significant increase in α-helicity and a transition to a more compact conformation. Our results provide the first structure of SenB and set the stage for further biochemical characterization in the future.
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Affiliation(s)
- Kendra
A. Ireland
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Chase M. Kayrouz
- Department
of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Jonathan Huang
- Department
of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Mohammad R. Seyedsayamdost
- Department
of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
- Department
of Molecular Biology, Princeton University, Princeton, New Jersey 08544, United States
| | - Katherine M. Davis
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
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9
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Karki R, Hennek JT, Chen W, Frantom PA. HDX-MS Reveals Substrate-Dependent, Localized EX1 Conformational Dynamics in the Retaining GT-B Glycosyltransferase, MshA. Biochemistry 2023; 62:2645-2657. [PMID: 37589157 DOI: 10.1021/acs.biochem.3c00338] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/18/2023]
Abstract
Glycosyltransferases (GTs) are well-characterized with respect to static 3D structures and molecular dynamics simulations, but there is a lack of reports on in-solution dynamics on time scales relevant to turnover. Here, backbone amide hydrogen/deuterium exchange followed by mass spectrometry (HDX-MS) was used to investigate the in-solution dynamics of the model retaining GT MshA from Corynebacterium glutamicum (CgMshA). CgMshA has a GT-B fold and catalyzes the transfer of N-acetyl-glucosamine (GlcNAc) from UDP-GlcNAc to l-myo-inositol-1-phosphate in the first step in mycothiol biosynthesis. HDX-MS results identify several key regions of conformational changes in response to UDP-GlcNAc binding, including residues 159-198 in the N-terminal domain and residues 323-354 in the C-terminal domain. These regions also exhibited substrate-dependent EX1 exchange kinetics consistent with conformational tension on the milliseconds to seconds time scale. A potential source of this conformational change is the flexible β4/α5 loop in the C-terminal domain, which sits at the interface of the two domains and likely interacts with the GlcNAc ring of UDP-GlcNAc. In contrast to UDP-GlcNAc, the UDP-CgMshA product complex exhibited severe decreases in deuterium incorporation, suggesting a less dynamic conformation. The HDX-MS results are complemented by solvent viscosity effects of 1.8-2.3 on the CgMshA kcat value, which are consistent with product release as a rate-determining step and possibly a direct role for protein dynamics in catalysis. The identification of in-solution dynamics that are sensitive to substrate binding allows for the proposal of a more detailed mechanism in CgMshA including conformation tension between the donor sugar and the flexible C-terminal domain β4/α5 loop providing sufficient conformational sampling for substrate-assisted catalysis to occur.
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Affiliation(s)
- Ramesh Karki
- Department of Chemistry & Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Jacquelyn T Hennek
- Department of Chemistry & Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Wen Chen
- Department of Chemistry & Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Patrick A Frantom
- Department of Chemistry & Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487, United States
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10
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Bloch JS, John A, Mao R, Mukherjee S, Boilevin J, Irobalieva RN, Darbre T, Scott NE, Reymond JL, Kossiakoff AA, Goddard-Borger ED, Locher KP. Structure, sequon recognition and mechanism of tryptophan C-mannosyltransferase. Nat Chem Biol 2023; 19:575-584. [PMID: 36604564 PMCID: PMC10154233 DOI: 10.1038/s41589-022-01219-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 10/28/2022] [Indexed: 01/07/2023]
Abstract
C-linked glycosylation is essential for the trafficking, folding and function of secretory and transmembrane proteins involved in cellular communication processes. The tryptophan C-mannosyltransferase (CMT) enzymes that install the modification attach a mannose to the first tryptophan of WxxW/C sequons in nascent polypeptide chains by an unknown mechanism. Here, we report cryogenic-electron microscopy structures of Caenorhabditis elegans CMT in four key states: apo, acceptor peptide-bound, donor-substrate analog-bound and as a trapped ternary complex with both peptide and a donor-substrate mimic bound. The structures indicate how the C-mannosylation sequon is recognized by this CMT and its paralogs, and how sequon binding triggers conformational activation of the donor substrate: a process relevant to all glycosyltransferase C superfamily enzymes. Our structural data further indicate that the CMTs adopt an unprecedented electrophilic aromatic substitution mechanism to enable the C-glycosylation of proteins. These results afford opportunities for understanding human disease and therapeutic targeting of specific CMT paralogs.
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Affiliation(s)
- Joël S Bloch
- Institute of Molecular Biology and Biophysics, ETH Zürich, Zürich, Switzerland
- Laboratory of Molecular Neurobiology and Biophysics and Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA
| | - Alan John
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Runyu Mao
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Somnath Mukherjee
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA
| | - Jérémy Boilevin
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
| | | | - Tamis Darbre
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
| | - Nichollas E Scott
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Parkville, Victoria, Australia
| | - Jean-Louis Reymond
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
| | - Anthony A Kossiakoff
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA
| | - Ethan D Goddard-Borger
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.
- Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia.
| | - Kaspar P Locher
- Institute of Molecular Biology and Biophysics, ETH Zürich, Zürich, Switzerland.
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11
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Maranha A, Costa M, Ripoll-Rozada J, Manso JA, Miranda V, Mendes VM, Manadas B, Macedo-Ribeiro S, Ventura MR, Pereira PJB, Empadinhas N. Self-recycling and partially conservative replication of mycobacterial methylmannose polysaccharides. Commun Biol 2023; 6:108. [PMID: 36707645 PMCID: PMC9883506 DOI: 10.1038/s42003-023-04448-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 01/10/2023] [Indexed: 01/29/2023] Open
Abstract
The steep increase in nontuberculous mycobacteria (NTM) infections makes understanding their unique physiology an urgent health priority. NTM synthesize two polysaccharides proposed to modulate fatty acid metabolism: the ubiquitous 6-O-methylglucose lipopolysaccharide, and the 3-O-methylmannose polysaccharide (MMP) so far detected in rapidly growing mycobacteria. The recent identification of a unique MMP methyltransferase implicated the adjacent genes in MMP biosynthesis. We report a wide distribution of this gene cluster in NTM, including slowly growing mycobacteria such as Mycobacterium avium, which we reveal to produce MMP. Using a combination of MMP purification and chemoenzymatic syntheses of intermediates, we identified the biosynthetic mechanism of MMP, relying on two enzymes that we characterized biochemically and structurally: a previously undescribed α-endomannosidase that hydrolyses MMP into defined-sized mannoligosaccharides that prime the elongation of new daughter MMP chains by a rare α-(1→4)-mannosyltransferase. Therefore, MMP biogenesis occurs through a partially conservative replication mechanism, whose disruption affected mycobacterial growth rate at low temperature.
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Affiliation(s)
- Ana Maranha
- grid.8051.c0000 0000 9511 4342CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal ,grid.8051.c0000 0000 9511 4342CIBB - Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal ,grid.8051.c0000 0000 9511 4342IIIUC - Institute of Interdisciplinary Research, University of Coimbra, 3030-789 Coimbra, Portugal
| | - Mafalda Costa
- grid.8051.c0000 0000 9511 4342CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal
| | - Jorge Ripoll-Rozada
- grid.5808.50000 0001 1503 7226IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal ,grid.5808.50000 0001 1503 7226Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal ,grid.507090.b0000 0004 5303 6218Present Address: Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Cantabria, Santander, Spain
| | - José A. Manso
- grid.5808.50000 0001 1503 7226IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal ,grid.5808.50000 0001 1503 7226Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
| | - Vanessa Miranda
- grid.10772.330000000121511713Bioorganic Chemistry Group, Instituto de Tecnologia Química Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Av. da República, 2780-157 Oeiras, Portugal
| | - Vera M. Mendes
- grid.8051.c0000 0000 9511 4342CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal ,grid.8051.c0000 0000 9511 4342CIBB - Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal
| | - Bruno Manadas
- grid.8051.c0000 0000 9511 4342CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal ,grid.8051.c0000 0000 9511 4342CIBB - Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal
| | - Sandra Macedo-Ribeiro
- grid.5808.50000 0001 1503 7226IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal ,grid.5808.50000 0001 1503 7226Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
| | - M. Rita Ventura
- grid.10772.330000000121511713Bioorganic Chemistry Group, Instituto de Tecnologia Química Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Av. da República, 2780-157 Oeiras, Portugal
| | - Pedro José Barbosa Pereira
- grid.5808.50000 0001 1503 7226IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal ,grid.5808.50000 0001 1503 7226Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
| | - Nuno Empadinhas
- grid.8051.c0000 0000 9511 4342CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal ,grid.8051.c0000 0000 9511 4342CIBB - Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal ,grid.8051.c0000 0000 9511 4342IIIUC - Institute of Interdisciplinary Research, University of Coimbra, 3030-789 Coimbra, Portugal
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12
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Paparella A, Cahill SM, Aboulache BL, Schramm VL. Clostridioides difficile TcdB Toxin Glucosylates Rho GTPase by an S Ni Mechanism and Ion Pair Transition State. ACS Chem Biol 2022; 17:2507-2518. [PMID: 36038138 PMCID: PMC9486934 DOI: 10.1021/acschembio.2c00408] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Toxins TcdA and TcdB from Clostridioides difficile glucosylate human colon Rho GTPases. TcdA and TcdB glucosylation of RhoGTPases results in cytoskeletal changes, causing cell rounding and loss of intestinal integrity. Clostridial toxins TcdA and TcdB are proposed to catalyze glucosylation of Rho GTPases with retention of stereochemistry from UDP-glucose. We used kinetic isotope effects to analyze the mechanisms and transition-state structures of the glucohydrolase and glucosyltransferase activities of TcdB. TcdB catalyzes Rho GTPase glucosylation with retention of stereochemistry, while hydrolysis of UDP-glucose by TcdB causes inversion of stereochemistry. Kinetic analysis revealed TcdB glucosylation via the formation of a ternary complex with no intermediate, supporting an SNi mechanism with nucleophilic attack and leaving group departure occurring on the same face of the glucose ring. Kinetic isotope effects combined with quantum mechanical calculations revealed that the transition states of both glucohydrolase and glucosyltransferase activities of TcdB are highly dissociative. Specifically, the TcdB glucosyltransferase reaction proceeds via an SNi mechanism with the formation of a distinct oxocarbenium phosphate ion pair transition state where the glycosidic bond to the UDP leaving group breaks prior to attack of the threonine nucleophile from Rho GTPase.
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13
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Bhattacharje G, Ghosh A, Das AK. Understanding the Mannose Transfer Mechanism of Mycobacterial Phosphatidyl-myo-inositol Mannosyltransferase A from Molecular Dynamics Simulations. ACS OMEGA 2022; 7:19288-19304. [PMID: 35721920 PMCID: PMC9202250 DOI: 10.1021/acsomega.2c00832] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 05/20/2022] [Indexed: 06/15/2023]
Abstract
Glycolipids like phosphatidylinositol hexamannosides (PIM6) and lipoglycans, such as lipomannan (LM) and lipoarabinomannan (LAM), play crucial roles in virulence, survival, and antibiotic resistance of various mycobacterial species. Phosphatidyl-myo-inositol mannosyltransferase A (PimA) catalyzes the transfer of the mannose moiety (M) from GDP-mannose (GDPM) to phosphatidyl-myo-inositol (PI) to synthesize GDP and phosphatidyl-myo-inositol monomannoside (PIM). This PIM is mannosylated, acylated, and further modified to give rise to the higher PIMs, LM, and LAM. It is yet to be known how PI, PIM, PI-GDPM, and PIM-GDP interact with PimA. Here, we report the docked structures of PI and PIM to understand how the substrates and the products interact with PimA. Using molecular dynamics (MD) simulations for 300 ns, we have investigated how various ligand-bound conformations change the dynamics of PimA. Our studies demonstrated the "open to closed" motions of PimA. We observed that PimA is least dynamic when bound to both GDPM and PI. MD simulations indicated that the loop residues 59-70 and the α-helical residues 73-86 of PimA play important roles while interacting with both PI and PIM. MD analyses also suggested that the residues Y9, P59, R68, L69, N97, R196, R201, K202, and R228 of PimA play significant roles in the mannose transfer reaction. Overall, docking studies and MD simulations provide crucial insights to design future therapeutic drugs against mycobacterial PimA.
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Affiliation(s)
- Gourab Bhattacharje
- Department
of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Amit Ghosh
- School
of Energy Science and Engineering, Indian
Institute of Technology Kharagpur, Kharagpur 721302, India
- P.K.
Sinha Centre for Bioenergy and Renewables, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Amit Kumar Das
- Department
of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
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14
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The Proteobacterial Methanotroph Methylosinus trichosporium OB3b Remodels Membrane Lipids in Response to Phosphate Limitation. mBio 2022; 13:e0024722. [PMID: 35575546 PMCID: PMC9239053 DOI: 10.1128/mbio.00247-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
Methane is a potent greenhouse gas in the atmosphere, and its concentration has continued to increase in recent decades. Aerobic methanotrophs, bacteria that use methane as the sole carbon source, are an important biological sink for methane, and they are widely distributed in the natural environment. However, relatively little is known on how methanotroph activity is regulated by nutrients, particularly phosphorus (P). P is the principal nutrient constraining plant and microbial productivity in many ecosystems, ranging from agricultural land to the open ocean. Using a model methanotrophic bacterium, Methylosinus trichosporium OB3b, we demonstrate here that this bacterium can produce P-free glycolipids to replace membrane phospholipids in response to P limitation. The formation of the glycolipid monoglucuronic acid diacylglycerol requires plcP-agt genes since the plcP-agt mutant is unable to produce this glycolipid. This plcP-agt-mediated lipid remodeling pathway appears to be important for M. trichosporium OB3b to cope with P stress, and the mutant grew significantly slower under P limitation. Interestingly, comparative genomics analysis shows that the ability to perform lipid remodeling appears to be a conserved trait in proteobacterial methanotrophs; indeed, plcP is found in all proteobacterial methanotroph genomes, and plcP transcripts from methanotrophs are readily detectable in metatranscriptomics data sets. Together, our study provides new insights into the adaptation to P limitation in this ecologically important group of bacteria.
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15
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Hassan BA, Milicaj J, Ramirez-Mondragon CA, Sham YY, Taylor EA. Ligand-Induced Conformational and Dynamical Changes in a GT-B Glycosyltransferase: Molecular Dynamics Simulations of Heptosyltransferase I Complexes. J Chem Inf Model 2022; 62:324-339. [PMID: 34967618 PMCID: PMC8864558 DOI: 10.1021/acs.jcim.1c00868] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Understanding the dynamical motions and ligand recognition motifs of heptosyltransferase I (HepI) can be critical to discerning the behavior of other glycosyltransferase (GT) enzymes. Prior studies in our lab have demonstrated that GTs in the GT-B structural class, which are characterized by their connection of two Rossman-like domains by a linker region, have conserved structural fold and dynamical motions, despite low sequence homology, therefore making discoveries found in HepI transferable to other GT-B enzymes. Through molecular dynamics simulations and ligand binding free energy analysis of HepI in the apo and bound complexes (for all kinetically relevant combinations of the native substrates/products), we have determined the energetically favored enzymatic pathway for ligand binding and release. Our principal component, dynamic cross correlation, and network analyses of the simulations have revealed correlated motions involving residues within the N-terminal domain communicating with C-terminal domain residues via both proximal amino acid residues and also functional groups of the bound substrates. Analyses of the structural changes, energetics of substrate/product binding, and changes in pKa have elucidated a variety of inter and intradomain interactions that are critical for enzyme catalysis. These data corroborate our experimental observations of protein conformational changes observed in both presteady state kinetic and circular dichroism analyses of HepI. These simulations provided invaluable structural insights into the regions involved in HepI conformational rearrangement upon ligand binding. Understanding the specific interactions governing conformational changes is likely to enhance our efforts to develop novel dynamics disrupting inhibitors against GT-B structural enzymes in the future.
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Affiliation(s)
- Bakar A. Hassan
- Department of Chemistry, Wesleyan University, Middletown, Connecticut 06459, United States
| | - Jozafina Milicaj
- Department of Chemistry, Wesleyan University, Middletown, Connecticut 06459, United States
| | - Carlos Andres Ramirez-Mondragon
- Department of Integrative Biology and Physiology, Medical School and Bioinformatics and Computational Biology Program, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Yuk Yin Sham
- Department of Integrative Biology and Physiology, Medical School and Bioinformatics and Computational Biology Program, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Erika A. Taylor
- Department of Chemistry, Wesleyan University, Middletown, Connecticut 06459, United States
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16
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Wear SS, Sande C, Ovchinnikova OG, Preston A, Whitfield C. Investigation of core machinery for biosynthesis of Vi antigen capsular polysaccharides in Gram-negative bacteria. J Biol Chem 2021; 298:101486. [PMID: 34896394 PMCID: PMC8760489 DOI: 10.1016/j.jbc.2021.101486] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 12/01/2021] [Accepted: 12/03/2021] [Indexed: 11/18/2022] Open
Abstract
Salmonella enterica serovar Typhi causes typhoid fever. It possesses a Vi antigen capsular polysaccharide coat that is important for virulence and is the basis of a current glycoconjugate vaccine. Vi antigen is also produced by environmental Bordetella isolates, while mammal-adapted Bordetella species (such as Bordetella bronchiseptica) produce a capsule of undetermined structure that cross-reacts with antibodies recognizing Vi antigen. The Vi antigen backbone is composed of poly-α-(1→4)-linked N-acetylgalactosaminuronic acid, modified with O-acetyl residues that are necessary for vaccine efficacy. Despite its biological and biotechnological importance, some central aspects of Vi antigen production are poorly understood. Here we demonstrate that TviE and TviD, two proteins encoded in the viaB (Vi antigen production) locus, interact and are the Vi antigen polymerase and O-acetyltransferase, respectively. Structural modeling and site-directed mutagenesis reveal that TviE is a GT4-family glycosyltransferase. While TviD has no identifiable homologs beyond Vi antigen systems in other bacteria, structural modeling suggests that it belongs to the large SGNH hydrolase family, which contains other O-acetyltransferases. Although TviD possesses an atypical catalytic triad, its O-acetyltransferase function was verified by antibody reactivity and 13C NMR data for tviD-mutant polysaccharide. The B. bronchiseptica genetic locus predicts a mode of synthesis distinct from classical S. enterica Vi antigen production, but which still involves TviD and TviE homologs that are both active in a reconstituted S. Typhi system. These findings provide new insight into Vi antigen production and foundational information for the glycoengineering of Vi antigen production in heterologous bacteria.
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Affiliation(s)
- Samantha S Wear
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Caitlin Sande
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Olga G Ovchinnikova
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Andrew Preston
- Milner Centre for Evolution and Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath, UK
| | - Chris Whitfield
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada.
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17
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Paudel S, Wachira J, McCarthy PC. Towards Computationally Guided Design and Engineering of a Neisseria meningitidis Serogroup W Capsule Polymerase with Altered Substrate Specificity. Processes (Basel) 2021; 9:2192. [PMID: 37483532 PMCID: PMC10361700 DOI: 10.3390/pr9122192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/25/2023] Open
Abstract
Heavy metal contamination of drinking water is a public health concern that requires the development of more efficient bioremediation techniques. Absorption technologies, including biosorption, provide opportunities for improvements to increase the diversity of target metal ions and overall binding capacity. Microorganisms are a key component in wastewater treatment plants, and they naturally bind metal ions through surface macromolecules but with limited capacity. The long-term goal of this work is to engineer capsule polymerases to synthesize molecules with novel functionalities. In previously published work, we showed that the Neisseria meningitidis serogroup W (NmW) galactose-sialic acid (Gal-NeuNAc) heteropolysaccharide binds lead ions effectively, thereby demonstrating the potential for its use in environmental decontamination applications. In this study, computational analysis of the NmW capsule polymerase galactosyltransferase (GT) domain was used to gain insight into how the enzyme could be modified to enable the synthesis of N-acetylgalactosamine-sialic acid (GalNAc-NeuNAc) heteropolysaccharide. Various computational approaches, including molecular modeling with I-TASSER and molecular dynamics (MD) simulations with NAMD, were utilized to identify key amino acid residues in the substrate binding pocket of the GT domain that may be key to conferring UDP-GalNAc specificity. Through these combined strategies and using BshA, a UDP-GlcNAc transferase, as a structural template, several NmW active site residues were identified as mutational targets to accommodate the proposed N-acetyl group in UDP-GalNAc. Thus, a rational approach for potentially conferring new properties to bacterial capsular polysaccharides is demonstrated.
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Affiliation(s)
- Subhadra Paudel
- Department of Computer Science, Morgan State University, Baltimore, MD 21251, USA
| | - James Wachira
- Department of Biology, Morgan State University, Baltimore, MD 21251, USA
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18
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Jeong H, Kim Y, Lee HS. OsnR is an autoregulatory negative transcription factor controlling redox-dependent stress responses in Corynebacterium glutamicum. Microb Cell Fact 2021; 20:203. [PMID: 34663317 PMCID: PMC8524982 DOI: 10.1186/s12934-021-01693-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 10/07/2021] [Indexed: 01/11/2023] Open
Abstract
Background Corynebacterium glutamicum is used in the industrial production of amino acids and nucleotides. During the course of fermentation, C. glutamicum cells face various stresses and employ multiple regulatory genes to cope with the oxidative stress. The osnR gene plays a negative regulatory role in redox-dependent oxidative-stress responses, but the underlying mechanism is not known yet. Results Overexpression of the osnR gene in C. glutamicum affected the expression of genes involved in the mycothiol metabolism. ChIP-seq analysis revealed that OsnR binds to the promoter region of multiple genes, including osnR and cg0026, which seems to function in the membrane-associated redox metabolism. Studies on the role of the osnR gene involving in vitro assays employing purified OsnR proteins and in vivo physiological analyses have identified that OsnR inhibits the transcription of its own gene. Further, oxidant diamide stimulates OsnR-binding to the promoter region of the osnR gene. The genes affected by the overexpression of osnR have been found to be under the control of σH. In the osnR-overexpressing strain, the transcription of sigH is significantly decreased and the stimulation of sigH transcription by external stress is lost, suggesting that osnR and sigH form an intimate regulatory network. Conclusions Our study suggests that OsnR not only functions as a transcriptional repressor of its own gene and of those involved in redox-dependent stress responses but also participates in the global transcriptional regulation by controlling the transcription of other master regulators, such as sigH. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-021-01693-1.
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Affiliation(s)
- Haeri Jeong
- Department of Biotechnology and Bioinformatics, Korea University, Sejong, Republic of Korea
| | - Younhee Kim
- Department of Korean Medicine, Semyung University, Jecheon, Chungbuk, Republic of Korea
| | - Heung-Shick Lee
- Department of Biotechnology and Bioinformatics, Korea University, Sejong, Republic of Korea.
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19
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A Glycolipid Glycosyltransferase with Broad Substrate Specificity from the Marine Bacterium " Candidatus Pelagibacter sp." Strain HTCC7211. Appl Environ Microbiol 2021; 87:e0032621. [PMID: 33931419 PMCID: PMC8231724 DOI: 10.1128/aem.00326-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
In the marine environment, phosphorus availability significantly affects the lipid composition in many cosmopolitan marine heterotrophic bacteria, including members of the SAR11 clade and the Roseobacter clade. Under phosphorus stress conditions, nonphosphorus sugar-containing glycoglycerolipids are substitutes for phospholipids in these bacteria. Although these glycoglycerolipids play an important role as surrogates for phospholipids under phosphate deprivation, glycoglycerolipid synthases in marine microbes are poorly studied. In the present study, we biochemically characterized a glycolipid glycosyltransferase (GTcp) from the marine bacterium “Candidatus Pelagibacter sp.” strain HTCC7211, a member of the SAR11 clade. Our results showed that GTcp is able to act as a multifunctional enzyme by synthesizing different glycoglycerolipids with UDP-glucose, UDP-galactose, or UDP-glucuronic acid as sugar donors and diacylglycerol (DAG) as the acceptor. Analyses of enzyme kinetic parameters demonstrated that Mg2+ notably changes the enzyme’s affinity for UDP-glucose, which improves its catalytic efficiency. Homology modeling and mutational analyses revealed binding sites for the sugar donor and the diacylglycerol lipid acceptor, which provided insights into the retaining mechanism of GTcp with its GT-B fold. A phylogenetic analysis showed that GTcp and its homologs form a group in the GT4 glycosyltransferase family. These results not only provide new insights into the glycoglycerolipid synthesis mechanism in lipid remodeling but also describe an efficient enzymatic tool for the future synthesis of bioactive molecules. IMPORTANCE The bilayer formed by membrane lipids serves as the containment unit for living microbial cells. In the marine environment, it has been firmly established that phytoplankton and heterotrophic bacteria can replace phospholipids with nonphosphorus sugar-containing glycoglycerolipids in response to phosphorus limitation. However, little is known about how these glycoglycerolipids are synthesized. Here, we determined the biochemical characteristics of a glycolipid glycosyltransferase (GTcp) from the marine bacterium “Candidatus Pelagibacter sp.” strain HTCC7211. GTcp and its homologs form a group in the GT4 glycosyltransferase family and can synthesize neutral glycolipids (monoglucosyl-1,2-diacyl-sn-glycerol [MGlc-DAG] and monogalactosyl [MGal]-DAG) and monoglucuronic acid diacylglycerol (MGlcA-DAG). We also uncovered the key residues for DAG binding through molecular docking, site-direct mutagenesis, and subsequent enzyme activity assays. Our data provide new insights into the glycoglycerolipid synthesis mechanism in lipid remodeling.
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20
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Kaur G, Iyer LM, Burroughs AM, Aravind L. Bacterial death and TRADD-N domains help define novel apoptosis and immunity mechanisms shared by prokaryotes and metazoans. eLife 2021; 10:70394. [PMID: 34061031 PMCID: PMC8195603 DOI: 10.7554/elife.70394] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Accepted: 05/23/2021] [Indexed: 12/12/2022] Open
Abstract
Several homologous domains are shared by eukaryotic immunity and programmed cell-death systems and poorly understood bacterial proteins. Recent studies show these to be components of a network of highly regulated systems connecting apoptotic processes to counter-invader immunity, in prokaryotes with a multicellular habit. However, the provenance of key adaptor domains, namely those of the Death-like and TRADD-N superfamilies, a quintessential feature of metazoan apoptotic systems, remained murky. Here, we use sensitive sequence analysis and comparative genomics methods to identify unambiguous bacterial homologs of the Death-like and TRADD-N superfamilies. We show the former to have arisen as part of a radiation of effector-associated α-helical adaptor domains that likely mediate homotypic interactions bringing together diverse effector and signaling domains in predicted bacterial apoptosis- and counter-invader systems. Similarly, we show that the TRADD-N domain defines a key, widespread signaling bridge that links effector deployment to invader-sensing in multicellular bacterial and metazoan counter-invader systems. TRADD-N domains are expanded in aggregating marine invertebrates and point to distinctive diversifying immune strategies probably directed both at RNA and retroviruses and cellular pathogens that might infect such communities. These TRADD-N and Death-like domains helped identify several new bacterial and metazoan counter-invader systems featuring underappreciated, common functional principles: the use of intracellular invader-sensing lectin-like (NPCBM and FGS), transcription elongation GreA/B-C, glycosyltransferase-4 family, inactive NTPase (serving as nucleic acid receptors), and invader-sensing GTPase switch domains. Finally, these findings point to the possibility of multicellular bacteria-stem metazoan symbiosis in the emergence of the immune/apoptotic systems of the latter.
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Affiliation(s)
- Gurmeet Kaur
- Computational Biology Branch, National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, United States
| | - Lakshminarayan M Iyer
- Computational Biology Branch, National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, United States
| | - A Maxwell Burroughs
- Computational Biology Branch, National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, United States
| | - L Aravind
- Computational Biology Branch, National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, United States
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21
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Ramirez-Mondragon CA, Nguyen ME, Milicaj J, Hassan BA, Tucci FJ, Muthyala R, Gao J, Taylor EA, Sham YY. Conserved Conformational Hierarchy across Functionally Divergent Glycosyltransferases of the GT-B Structural Superfamily as Determined from Microsecond Molecular Dynamics. Int J Mol Sci 2021; 22:ijms22094619. [PMID: 33924837 PMCID: PMC8124905 DOI: 10.3390/ijms22094619] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 04/23/2021] [Accepted: 04/26/2021] [Indexed: 11/19/2022] Open
Abstract
It has long been understood that some proteins undergo conformational transitions en route to the Michaelis Complex to allow chemistry. Examination of crystal structures of glycosyltransferase enzymes in the GT-B structural class reveals that the presence of ligand in the active site triggers an open-to-closed conformation transition, necessary for their catalytic functions. Herein, we describe microsecond molecular dynamics simulations of two distantly related glycosyltransferases that are part of the GT-B structural superfamily, HepI and GtfA. Simulations were performed using the open and closed conformations of these unbound proteins, respectively, and we sought to identify the major dynamical modes and communication networks that interconnect the open and closed structures. We provide the first reported evidence within the scope of our simulation parameters that the interconversion between open and closed conformations is a hierarchical multistep process which can be a conserved feature of enzymes of the same structural superfamily. Each of these motions involves of a collection of smaller molecular reorientations distributed across both domains, highlighting the complexities of protein dynamic involved in the interconversion process. Additionally, dynamic cross-correlation analysis was employed to explore the potential effect of distal residues on the catalytic efficiency of HepI. Multiple distal nonionizable residues of the C-terminal domain exhibit motions anticorrelated to positively charged residues in the active site in the N-terminal domain involved in substrate binding. Mutations of these residues resulted in a reduction in negatively correlated motions and an altered enzymatic efficiency that is dominated by lower Km values with kcat effectively unchanged. The findings suggest that residues with opposing conformational motions involved in the opening and closing of the bidomain HepI protein can allosterically alter the population and conformation of the “closed” state, essential to the formation of the Michaelis complex. The stabilization effects of these mutations likely equally influence the energetics of both the ground state and the transition state of the catalytic reaction, leading to the unaltered kcat. Our study provides new insights into the role of conformational dynamics in glycosyltransferase’s function and new modality to modulate enzymatic efficiency.
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Affiliation(s)
- Carlos A. Ramirez-Mondragon
- Bioinformatics and Computational Biology Program, University of Minnesota, Minneapolis, MN 55455, USA; (C.A.R.-M.); (M.E.N.); (J.G.)
| | - Megin E. Nguyen
- Bioinformatics and Computational Biology Program, University of Minnesota, Minneapolis, MN 55455, USA; (C.A.R.-M.); (M.E.N.); (J.G.)
| | - Jozafina Milicaj
- Department of Chemistry, Wesleyan University, Middletown, CT 06459, USA; (J.M.); (B.A.H.); (F.J.T.)
| | - Bakar A. Hassan
- Department of Chemistry, Wesleyan University, Middletown, CT 06459, USA; (J.M.); (B.A.H.); (F.J.T.)
| | - Frank J. Tucci
- Department of Chemistry, Wesleyan University, Middletown, CT 06459, USA; (J.M.); (B.A.H.); (F.J.T.)
| | - Ramaiah Muthyala
- Department of Experimental and Clinical Pharmacology, College Pharmacy, University of Minnesota, Minneapolis, MN 55455, USA;
| | - Jiali Gao
- Bioinformatics and Computational Biology Program, University of Minnesota, Minneapolis, MN 55455, USA; (C.A.R.-M.); (M.E.N.); (J.G.)
- Department of Chemistry, University of Minnesota, Minneapolis, Minneapolis, MN 55455, USA
- Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen 518055, China
| | - Erika A. Taylor
- Department of Chemistry, Wesleyan University, Middletown, CT 06459, USA; (J.M.); (B.A.H.); (F.J.T.)
- Correspondence: (E.A.T.); (Y.Y.S.); Tel.: +1-(860)-685-2739 (E.A.T.); +1-(612)-625-6255 (Y.Y.S.); Fax: +1-(860)-685-2211 (E.A.T.); +1-(612)-625-5149 (Y.Y.S.)
| | - Yuk Y. Sham
- Bioinformatics and Computational Biology Program, University of Minnesota, Minneapolis, MN 55455, USA; (C.A.R.-M.); (M.E.N.); (J.G.)
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, MN 55455, USA
- Correspondence: (E.A.T.); (Y.Y.S.); Tel.: +1-(860)-685-2739 (E.A.T.); +1-(612)-625-6255 (Y.Y.S.); Fax: +1-(860)-685-2211 (E.A.T.); +1-(612)-625-5149 (Y.Y.S.)
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22
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Lira-Navarrete E, Pallarés MC, Castello F, Ruedas-Rama MJ, Orte A, Lostao A, Hurtado-Guerrero R. Protein O-Fucosyltransferase 1 Undergoes Interdomain Flexibility in Solution. Molecules 2021; 26:2105. [PMID: 33916911 PMCID: PMC8067585 DOI: 10.3390/molecules26082105] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 03/22/2021] [Accepted: 04/02/2021] [Indexed: 11/25/2022] Open
Abstract
Protein O-fucosyltransferase 1 (PoFUT1) is a GT-B fold enzyme that fucosylates proteins containing EGF-like repeats. GT-B glycosyltransferases have shown a remarkable grade of plasticity adopting closed and open conformations as a way of tuning their catalytic cycle, a feature that has not been observed for PoFUT1. Here, we analyzed Caenorhabditis elegans PoFUT1 (CePoFUT1) conformational behavior in solution by atomic force microscopy (AFM) and single-molecule fluorescence resonance energy transfer (SMF-FRET). Our results show that this enzyme is very flexible and adopts mainly compact conformations and to a lesser extend a highly dynamic population that oscillates between compact and highly extended conformations. Overall, our experiments illustrate the inherent complexity of CePoFUT1 dynamics, which might play a role during its catalytic cycle.
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Affiliation(s)
- Erandi Lira-Navarrete
- Institute of Biocomputation and Physics of Complex Systems (BIFI), University of Zaragoza, 50018 Zaragoza, Spain;
| | - María Carmen Pallarés
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain;
- Laboratorio de Microscopías Avanzadas (LMA), Universidad de Zaragoza, 50018 Zaragoza, Spain
| | - Fabio Castello
- Departamento de Fisicoquímica, Facultad de Farmacia, Universidad de Granada, 18071 Granada, Spain; (F.C.); (M.J.R.-R.)
| | - Maria J. Ruedas-Rama
- Departamento de Fisicoquímica, Facultad de Farmacia, Universidad de Granada, 18071 Granada, Spain; (F.C.); (M.J.R.-R.)
| | - Angel Orte
- Departamento de Fisicoquímica, Facultad de Farmacia, Universidad de Granada, 18071 Granada, Spain; (F.C.); (M.J.R.-R.)
| | - Anabel Lostao
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain;
- Laboratorio de Microscopías Avanzadas (LMA), Universidad de Zaragoza, 50018 Zaragoza, Spain
- Fundación ARAID, 50018 Zaragoza, Spain
| | - Ramón Hurtado-Guerrero
- Institute of Biocomputation and Physics of Complex Systems (BIFI), University of Zaragoza, 50018 Zaragoza, Spain;
- Laboratorio de Microscopías Avanzadas (LMA), Universidad de Zaragoza, 50018 Zaragoza, Spain
- Fundación ARAID, 50018 Zaragoza, Spain
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, School of Dentistry, University of Copenhagen, 2200 Copenhagen, Denmark
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23
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Rodrigo-Unzueta A, Ghirardello M, Urresti S, Delso I, Giganti D, Anso I, Trastoy B, Comino N, Tersa M, D'Angelo C, Cifuente JO, Marina A, Liebau J, Mäler L, Chenal A, Albesa-Jové D, Merino P, Guerin ME. Dissecting the Structural and Chemical Determinants of the "Open-to-Closed" Motion in the Mannosyltransferase PimA from Mycobacteria. Biochemistry 2020; 59:2934-2945. [PMID: 32786405 DOI: 10.1021/acs.biochem.0c00376] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The phosphatidyl-myo-inositol mannosyltransferase A (PimA) is an essential peripheral membrane glycosyltransferase that initiates the biosynthetic pathway of phosphatidyl-myo-inositol mannosides (PIMs), key structural elements and virulence factors of Mycobacterium tuberculosis. PimA undergoes functionally important conformational changes, including (i) α-helix-to-β-strand and β-strand-to-α-helix transitions and (ii) an "open-to-closed" motion between the two Rossmann-fold domains, a conformational change that is necessary to generate a catalytically competent active site. In previous work, we established that GDP-Man and GDP stabilize the enzyme and facilitate the switch to a more compact active state. To determine the structural contribution of the mannose ring in such an activation mechanism, we analyzed a series of chemical derivatives, including mannose phosphate (Man-P) and mannose pyrophosphate-ribose (Man-PP-RIB), and additional GDP derivatives, such as pyrophosphate ribose (PP-RIB) and GMP, by the combined use of X-ray crystallography, limited proteolysis, circular dichroism, isothermal titration calorimetry, and small angle X-ray scattering methods. Although the β-phosphate is present, we found that the mannose ring, covalently attached to neither phosphate (Man-P) nor PP-RIB (Man-PP-RIB), does promote the switch to the active compact form of the enzyme. Therefore, the nucleotide moiety of GDP-Man, and not the sugar ring, facilitates the "open-to-closed" motion, with the β-phosphate group providing the high-affinity binding to PimA. Altogether, the experimental data contribute to a better understanding of the structural determinants involved in the "open-to-closed" motion not only observed in PimA but also visualized and/or predicted in other glycosyltransfeases. In addition, the experimental data might prove to be useful for the discovery and/or development of PimA and/or glycosyltransferase inhibitors.
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Affiliation(s)
- Ane Rodrigo-Unzueta
- Instituto Biofisika, Centro Mixto Consejo Superior de Investigaciones Científicas-Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC, UPV/EHU), Barrio Sarriena s/n, Leioa, Bizkaia 48940, Spain.,Departamento de Bioquímica, Universidad del País Vasco, Barrio Sarriena s/n, Leioa, Bizkaia 48940, Spain
| | - Mattia Ghirardello
- Department of Synthesis and Structure of Biomolecules, Institute of Chemical Synthesis and Homogeneous Catalysis (ISQCH), University of Zaragoza-CSIC, 50009 Zaragoza, Spain
| | - Saioa Urresti
- Instituto Biofisika, Centro Mixto Consejo Superior de Investigaciones Científicas-Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC, UPV/EHU), Barrio Sarriena s/n, Leioa, Bizkaia 48940, Spain.,Departamento de Bioquímica, Universidad del País Vasco, Barrio Sarriena s/n, Leioa, Bizkaia 48940, Spain
| | - Ignacio Delso
- Department of Synthesis and Structure of Biomolecules, Institute of Chemical Synthesis and Homogeneous Catalysis (ISQCH), University of Zaragoza-CSIC, 50009 Zaragoza, Spain
| | - David Giganti
- Instituto Biofisika, Centro Mixto Consejo Superior de Investigaciones Científicas-Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC, UPV/EHU), Barrio Sarriena s/n, Leioa, Bizkaia 48940, Spain.,Departamento de Bioquímica, Universidad del País Vasco, Barrio Sarriena s/n, Leioa, Bizkaia 48940, Spain.,Unité de Microbiologie Structurale (CNRS URA 2185), Institut Pasteur, 25 rue du Dr. Roux, 75724 Paris Cedex 15, France
| | - Itxaso Anso
- Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain
| | - Beatriz Trastoy
- Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain
| | - Natalia Comino
- Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain
| | - Montse Tersa
- Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain
| | - Cecilia D'Angelo
- Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain
| | - Javier O Cifuente
- Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain
| | - Alberto Marina
- Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain
| | - Jobst Liebau
- Department of Biochemistry and Biophysics, Stockholm University, 106 91 Stockholm, Sweden
| | - Lena Mäler
- Department of Biochemistry and Biophysics, Stockholm University, 106 91 Stockholm, Sweden.,Department of Chemistry, Umeå University, 901 87 Umeå, Sweden
| | - Alexandre Chenal
- Unité de Biochimie des Interactions Macromoléculaires (CNRS UMR 3528), Institut Pasteur, 25 rue du Dr. Roux, 75724 Paris Cedex 15, France
| | - David Albesa-Jové
- Instituto Biofisika, Centro Mixto Consejo Superior de Investigaciones Científicas-Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC, UPV/EHU), Barrio Sarriena s/n, Leioa, Bizkaia 48940, Spain.,Departamento de Bioquímica, Universidad del País Vasco, Barrio Sarriena s/n, Leioa, Bizkaia 48940, Spain.,Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain.,IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
| | - Pedro Merino
- Glycobiology Unit, Institute of Biocomputation and Physics of Complex Systems (BIFI), University of Zaragoza, Campus San Francisco, 50009 Zaragoza, Spain
| | - Marcelo E Guerin
- Instituto Biofisika, Centro Mixto Consejo Superior de Investigaciones Científicas-Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC, UPV/EHU), Barrio Sarriena s/n, Leioa, Bizkaia 48940, Spain.,Departamento de Bioquímica, Universidad del País Vasco, Barrio Sarriena s/n, Leioa, Bizkaia 48940, Spain.,Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain.,IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
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24
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Li Y, Yao Y, Yang G, Tang J, Ayala GJ, Li X, Zhang W, Han Q, Yang T, Wang H, Mayo KH, Su J. Co-crystal Structure of Thermosynechococcus elongatus Sucrose Phosphate Synthase With UDP and Sucrose-6-Phosphate Provides Insight Into Its Mechanism of Action Involving an Oxocarbenium Ion and the Glycosidic Bond. Front Microbiol 2020; 11:1050. [PMID: 32528448 PMCID: PMC7264703 DOI: 10.3389/fmicb.2020.01050] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 04/28/2020] [Indexed: 12/17/2022] Open
Abstract
In green species, sucrose can help antagonize abiotic stress. Sucrose phosphate synthase (SPS) is a well-known rate-limiting enzyme in the synthesis of sucrose. To date, however, there is no known crystal structure of SPS from plant or cyanobacteria. In this study, we report the first co-crystal structure of SPS from Thermosynechococcus elongatus with UDP and sucrose-6-phosphate (S6P). Within the catalytic site, the side chains of His158 and Glu331, along with two phosphate groups from UDP, form hydrogen bonds with the four hydroxyl groups of the glucose moiety in S6P. This association causes these four hydroxyl groups to become partially negatively charged, thus promoting formation of the C1 oxocarbenium ion. Breakage of the hydrogen bond between His158 and one of the hydroxyl groups may trigger covalent bond formation between the C1 oxocarbenium ion and the C2 hydroxyl of fructose-6-phosphate. Consistent with our structural model, we observed that two SPS mutants, H158A and E331A, lost all catalytic activity. Moreover, electron density of residues from two loops (loop1 and loop2) in the SPS A-domain was not observed, suggest their dynamic nature. B-factor analysis and molecular dynamics stimulations of the full-length enzyme and A-domain indicate that both loops are crucial for binding and release of substrate and product. In addition, temperature gradient analysis shows that SPS exhibits its highest activity at 70°C, suggesting that this enzyme has the potential of being used in industrial production of S6P.
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Affiliation(s)
- Yuying Li
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun, China
| | - Yuan Yao
- Media Academy, Jilin Engineering Normal University, Changchun, China
| | | | - Jun Tang
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun, China
| | - Gabriela Jaramillo Ayala
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun, China
| | - Xumin Li
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun, China
| | - Wenlu Zhang
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun, China
| | - Qiuyu Han
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun, China
| | - Tong Yang
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun, China
| | - Hao Wang
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun, China
| | - Kevin H Mayo
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, United States
| | - Jiyong Su
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun, China
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25
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Syson K, Stevenson CEM, Lawson DM, Bornemann S. Structure of the Mycobacterium smegmatis α-maltose-1-phosphate synthase GlgM. Acta Crystallogr F Struct Biol Commun 2020; 76:175-181. [PMID: 32254051 PMCID: PMC7137382 DOI: 10.1107/s2053230x20004343] [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: 02/03/2020] [Accepted: 03/30/2020] [Indexed: 11/25/2022] Open
Abstract
Mycobacterium tuberculosis produces glycogen (also known as α-glucan) to help evade human immunity. This pathogen uses the GlgE pathway to generate glycogen rather than the more well known glycogen synthase GlgA pathway, which is absent in this bacterium. Thus, the building block for this glucose polymer is α-maltose-1-phosphate rather than an NDP-glucose donor. One of the routes to α-maltose-1-phosphate is now known to involve the GlgA homologue GlgM, which uses ADP-glucose as a donor and α-glucose-1-phosphate as an acceptor. To help compare GlgA (a GT5 family member) with GlgM enzymes (GT4 family members), the X-ray crystal structure of GlgM from Mycobacterium smegmatis was solved to 1.9 Å resolution. While the enzymes shared a GT-B fold and several residues responsible for binding the donor substrate, they differed in some secondary-structural details, particularly in the N-terminal domain, which would be expected to be largely responsible for their different acceptor-substrate specificities.
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Affiliation(s)
- Karl Syson
- Biological Chemistry Department, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Clare E. M. Stevenson
- Biological Chemistry Department, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - David M. Lawson
- Biological Chemistry Department, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Stephen Bornemann
- Biological Chemistry Department, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
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26
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Cote JM, Hecht CJS, Patel KR, Ramirez-Mondragon CA, Sham YY, Taylor EA. Opposites Attract: Escherichia coli Heptosyltransferase I Conformational Changes Induced by Interactions between the Substrate and Positively Charged Residues. Biochemistry 2020; 59:3135-3147. [PMID: 32011131 DOI: 10.1021/acs.biochem.9b01005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Gram-negative bacterial viability is greatly reduced by the disruption of heptose sugar addition during the biosynthesis of lipopolysaccharide (LPS), an important bacterial outer membrane component. Heptosyltransferase I (HepI), a member of the GT-B structural subclass of glycosyltransferases, is therefore an essential enzyme for the biosynthesis of the LPS. The disruption of HepI also increases the susceptibility of bacteria to hydrophobic antibiotics, making HepI a potential target for drug development. In this work, the structural and dynamic properties of the catalytic cycle of HepI are explored. Previously, substrate-induced stabilization of HepI was observed and hypothesized to be assisted by interactions between the substrate and residues located on dynamic loops. Herein, positively charged amino acids were probed to identify binding partners of the negatively charged phosphates and carboxylates of Kdo2-lipid A and its analogues. Mutant enzymes were characterized to explore changes in enzymatic activities and protein stability. Molecular modeling of HepI in the presence and absence of ligands was then performed with the wild type and mutant enzyme to allow determination of the relative change in substrate binding affinity resulting from each mutation. Together, these studies suggest that multiple residues are involved in mediating substrate binding, and a lack of additivity of these effects illustrates the functional redundancy of these binding interactions. The redundancy of residues mediating conformational transitions in HepI illustrates the evolutionary importance of these structural rearrangements for catalysis. This work enhances the understanding of HepI's protein dynamics and mechanism and is a model for improving our understanding of glycosyltransferase enzymes.
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Affiliation(s)
- Joy M Cote
- Department of Chemistry, Wesleyan University, Middletown, Connecticut 06459, United States
| | - Cody J S Hecht
- Department of Chemistry, Wesleyan University, Middletown, Connecticut 06459, United States
| | - Kaelan R Patel
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Carlos A Ramirez-Mondragon
- Bioinformatics and Computational Biology Program, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Yuk Y Sham
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota 55455, United States.,Bioinformatics and Computational Biology Program, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Erika A Taylor
- Department of Chemistry, Wesleyan University, Middletown, Connecticut 06459, United States
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27
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Zorzoli A, Meyer BH, Adair E, Torgov VI, Veselovsky VV, Danilov LL, Uhrin D, Dorfmueller HC. Group A, B, C, and G Streptococcus Lancefield antigen biosynthesis is initiated by a conserved α-d-GlcNAc-β-1,4-l-rhamnosyltransferase. J Biol Chem 2019; 294:15237-15256. [PMID: 31506299 PMCID: PMC6802508 DOI: 10.1074/jbc.ra119.009894] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 08/30/2019] [Indexed: 12/18/2022] Open
Abstract
Group A carbohydrate (GAC) is a bacterial peptidoglycan-anchored surface rhamnose polysaccharide (RhaPS) that is essential for growth of Streptococcus pyogenes and contributes to its ability to infect the human host. In this study, using molecular and synthetic biology approaches, biochemistry, radiolabeling techniques, and NMR and MS analyses, we examined the role of GacB, encoded in the S. pyogenes GAC gene cluster, in the GAC biosynthesis pathway. We demonstrate that GacB is the first characterized α-d-GlcNAc-β-1,4-l-rhamnosyltransferase that synthesizes the committed step in the biosynthesis of the GAC virulence determinant. Importantly, the substitution of S. pyogenes gacB with the homologous gene from Streptococcus agalactiae (Group B Streptococcus), Streptococcus equi subsp. zooepidemicus (Group C Streptococcus), Streptococcus dysgalactiae subsp. equisimilis (Group G Streptococcus), or Streptococcus mutans complemented the GAC biosynthesis pathway. These results, combined with those from extensive in silico studies, reveal a common phylogenetic origin of the genes required for this priming step in >40 pathogenic species of the Streptococcus genus, including members from the Lancefield Groups B, C, D, E, G, and H. Importantly, this priming step appears to be unique to streptococcal ABC transporter-dependent RhaPS biosynthesis, whereas the Wzx/Wzy-dependent streptococcal capsular polysaccharide pathways instead require an α-d-Glc-β-1,4-l-rhamnosyltransferase. The insights into the RhaPS priming step obtained here open the door to targeting the early steps of the group carbohydrate biosynthesis pathways in species of the Streptococcus genus of high clinical and veterinary importance.
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Affiliation(s)
- Azul Zorzoli
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, United Kingdom
| | - Benjamin H Meyer
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, United Kingdom
| | - Elaine Adair
- EaStCHEM School of Chemistry, University of Edinburgh, Edinburgh, EH9 3FJ, United Kingdom
| | - Vladimir I Torgov
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow 119334, Russia
| | - Vladimir V Veselovsky
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow 119334, Russia
| | - Leonid L Danilov
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow 119334, Russia
| | - Dusan Uhrin
- EaStCHEM School of Chemistry, University of Edinburgh, Edinburgh, EH9 3FJ, United Kingdom
| | - Helge C Dorfmueller
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, United Kingdom
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28
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Uddin R, Siddiqui QN, Sufian M, Azam SS, Wadood A. Proteome-wide subtractive approach to prioritize a hypothetical protein of XDR-Mycobacterium tuberculosis as potential drug target. Genes Genomics 2019; 41:1281-1292. [PMID: 31388979 DOI: 10.1007/s13258-019-00857-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Accepted: 07/25/2019] [Indexed: 12/12/2022]
Abstract
BACKGROUND Among the resistant isolates of MTB, multidrug resistant tuberculosis (MDR-TB) and extensively drug resistant tuberculosis (XDR-TB) have been the areas of growing concern. The genomic analysis showed that the respective genomic pool of the XDR-MTB proteome contains more than 30% of the hypothetical proteins for which no functions have been annotated yet. This class of proteins presumably have their own importance to complete genome and proteome information. The bioinformatics advancements have helped to annotate those hypothetical proteins by using various computational tools and have potential to classify them functionally. OBJECTIVE The objective of this study was to propose a new and unique drug target against the deadly Mycobacterium tuberculosis using Bioinformatics approaches to characterize the hypothetical proteins. RESULTS We stepwise reduced the hypothetical proteins (total number: 1256) out of the complete proteome to only 26 essential hypothetical proteins. Out of those 26 proteins, the protein WP_003401246.1 was computationally characterized as the druggable target. CONCLUSION The study proposed a hypothetical protein from complete proteome of the XDR-MTB as a new drug target against which new drug candidates can be proposed. Hence, the study opens up the new avenues in the areas of drug discovery against deadly M. tuberculosis.
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Affiliation(s)
- Reaz Uddin
- Lab 103 PCMD ext. Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, 75270, Pakistan.
| | - Quratulain Nehal Siddiqui
- Lab 103 PCMD ext. Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, 75270, Pakistan
| | - Muhammad Sufian
- Lab 103 PCMD ext. Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, 75270, Pakistan
| | - Syed Sikander Azam
- National Centre for Bioinformatics, Quaid-i-Azam University, Islamabad, Pakistan
| | - Abdul Wadood
- Department of Biochemistry, Abdul Wali Khan University, Mardan, Pakistan
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29
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Structural basis of glycogen metabolism in bacteria. Biochem J 2019; 476:2059-2092. [PMID: 31366571 DOI: 10.1042/bcj20170558] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 07/11/2019] [Accepted: 07/15/2019] [Indexed: 01/25/2023]
Abstract
The evolution of metabolic pathways is a major force behind natural selection. In the spotlight of such process lies the structural evolution of the enzymatic machinery responsible for the central energy metabolism. Specifically, glycogen metabolism has emerged to allow organisms to save available environmental surplus of carbon and energy, using dedicated glucose polymers as a storage compartment that can be mobilized at future demand. The origins of such adaptive advantage rely on the acquisition of an enzymatic system for the biosynthesis and degradation of glycogen, along with mechanisms to balance the assembly and disassembly rate of this polysaccharide, in order to store and recover glucose according to cell energy needs. The first step in the classical bacterial glycogen biosynthetic pathway is carried out by the adenosine 5'-diphosphate (ADP)-glucose pyrophosphorylase. This allosteric enzyme synthesizes ADP-glucose and acts as a point of regulation. The second step is carried out by the glycogen synthase, an enzyme that generates linear α-(1→4)-linked glucose chains, whereas the third step catalyzed by the branching enzyme produces α-(1→6)-linked glucan branches in the polymer. Two enzymes facilitate glycogen degradation: glycogen phosphorylase, which functions as an α-(1→4)-depolymerizing enzyme, and the debranching enzyme that catalyzes the removal of α-(1→6)-linked ramifications. In this work, we rationalize the structural basis of glycogen metabolism in bacteria to the light of the current knowledge. We describe and discuss the remarkable progress made in the understanding of the molecular mechanisms of substrate recognition and product release, allosteric regulation and catalysis of all those enzymes.
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Complex Structure of Pseudomonas aeruginosa Arginine Rhamnosyltransferase EarP with Its Acceptor Elongation Factor P. J Bacteriol 2019; 201:JB.00128-19. [PMID: 31010899 DOI: 10.1128/jb.00128-19] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 03/28/2019] [Indexed: 01/10/2023] Open
Abstract
A bacterial inverting glycosyltransferase EarP transfers rhamnose from dTDP-β-l-rhamnose (TDP-Rha) to Arg32 of translation elongation factor P (EF-P) to activate its function. We report here the structural and biochemical characterization of Pseudomonas aeruginosa EarP. In contrast to recently reported Neisseria meningitidis EarP, P. aeruginosa EarP exhibits differential conformational changes upon TDP-Rha and EF-P binding. Sugar donor binding enhances acceptor binding to EarP, as revealed by structural comparison between the apo-, TDP-Rha-, and TDP/EF-P-bound forms and isothermal titration calorimetry experiments. In vitro EF-P rhamnosylation combined with active-site geometry indicates that Asp16 corresponding to Asp20 of N. meningitidis EarP is the catalytic base, whereas Glu272 is another putative catalytic residue. Our study should provide the basis for EarP-targeted inhibitor design against infections from P. aeruginosa and other clinically relevant species.IMPORTANCE Posttranslational rhamnosylation of EF-P plays a key role in Pseudomonas aeruginosa, establishing virulence and antibiotic resistance, as well as survival. The detailed structural and biochemical characterization of the EF-P-specific rhamnosyltransferase EarP from P. aeruginosa not only demonstrates that sugar donor TDP-Rha binding enhances acceptor EF-P binding to EarP but also should provide valuable information for the structure-guided development of its inhibitors against infections from P. aeruginosa and other EarP-containing pathogens.
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Panda SK, Saxena S, Guruprasad L. Homology modeling, docking and structure-based virtual screening for new inhibitor identification of Klebsiella pneumoniae heptosyltransferase-III. J Biomol Struct Dyn 2019; 38:1887-1902. [PMID: 31179839 DOI: 10.1080/07391102.2019.1624296] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Klebsiella pneumoniae (K. pneumoniae) is a Gram-negative opportunistic pathogen commonly associated with hospital-acquired infections that are often resistant even to antibiotics. Heptosyltransferase (HEP) belongs to the family of glycosyltransferase-B (GT-B) and plays an important in the synthesis of lipopolysaccharides (LPS) essential for the formation of bacterial cell membrane. HEP-III participates in the transfer of heptose sugar to the outer surface of bacteria to synthesize LPS. LPS truncation increases the bacterial sensitivity to hydrophobic antibiotics and detergents, making the HEP as a novel drug target. In the present study, we report the 3D homology model of K. pneumoniae HEP-III and its structure validation. Active site was identified based on similarities with known structures using Dali server, and structure-based pharmacophore model was developed for the active site substrate ADP. The generated pharmacophore model was used as a 3D search query for virtual screening of the ASINEX database. The hit compounds were further filtered based on fit value, molecular docking, docking scores, molecular dynamics (MD) simulations of HEP-III complexed with hit molecules, followed by binding free energy calculations using Molecular Mechanics-Poisson-Boltzmann Surface Area (MM-PBSA). The insights obtained in this work provide the rationale for design of novel inhibitors targeting K. pneumoniae HEP-III and the mechanistic aspects of their binding. Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
| | - Shalini Saxena
- School of Chemistry, University of Hyderabad, Hyderabad, India
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32
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Guo Y, Gong W, Wang L, Guo J, Jin G, Gu G, Guo Z. Characterization and biochemical investigation of the potential inositol monophosphate phosphatase involved in bacterial mycothiol biosynthesis. J Carbohydr Chem 2019. [DOI: 10.1080/07328303.2018.1559326] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Yuchuan Guo
- National Glycoengineering Research Center and Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Jinan, China
- Department of Chemistry, University of Florida, Gainesville, USA
| | - Wei Gong
- National Glycoengineering Research Center and Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Jinan, China
| | - Lizhen Wang
- National Glycoengineering Research Center and Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Jinan, China
| | - Jiatong Guo
- Department of Chemistry, University of Florida, Gainesville, USA
| | - Guoxia Jin
- College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan, China
| | - Guofeng Gu
- National Glycoengineering Research Center and Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Jinan, China
| | - Zhongwu Guo
- National Glycoengineering Research Center and Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Jinan, China
- Department of Chemistry, University of Florida, Gainesville, USA
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Nkosana NK, Czyzyk DJ, Siegel ZS, Cote JM, Taylor EA. Synthesis, kinetics and inhibition of Escherichia coli Heptosyltransferase I by monosaccharide analogues of Lipid A. Bioorg Med Chem Lett 2018; 28:594-600. [PMID: 29398539 DOI: 10.1016/j.bmcl.2018.01.040] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 01/17/2018] [Accepted: 01/21/2018] [Indexed: 01/18/2023]
Abstract
Gram-negative bacteria comprise the majority of microbes that cause infections that are resistant to pre-existing antibiotics. The complex cell wall architecture contributes to their ability to form biofilms, which are often implicated in hospital-acquired infections. Biofilms promote antibiotic resistance by enabling the bacteria to survive hostile environments such as UV radiation, pH shifts, and antibiotics. The outer membrane of Gram-negative bacteria contains lipopolysaccharide (LPS), which plays a role in adhesion to surfaces and formation of biofilms. The main focus of this work was the synthesis of a library of glycolipids designed to be simplified analogues of the Lipid A, the membrane embedded portion component of LPS, to be tested as substrates or inhibitors of Heptosyltransferase I (HepI or WaaC, a glycosyltransferase enzyme involved in the biosynthesis of LPS). Fourteen analogues were synthesized successfully and characterized. While these compounds were designed to function as nucleophilic substrates of HepI, they all demonstrated mild inhibition of HepI. Kinetic characterization of inhibition mechanism identified that the compounds exhibited uncompetitive and mixed inhibition of HepI. Since both uncompetitive and mixed inhibition result in the formation of an Enzyme-Substrate-inhibitor complex, molecular docking studies (using AutoDock Vina) were performed, to identify potential allosteric binding site for these compounds. The inhibitors were shown to bind to a pocket formed after undergoing a conformational change from an open to a closed active site state. Inhibition of HepI via an allosteric site suggest that disruption of protein dynamics might be a viable mechanism for the inhibition of HepI and potentially other enzymes of the GT-B structural class.
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Affiliation(s)
- Noreen K Nkosana
- Department of Chemistry, Wesleyan University, Middletown, CT, 06459, United States
| | - Daniel J Czyzyk
- Department of Chemistry, Wesleyan University, Middletown, CT, 06459, United States
| | - Zarek S Siegel
- Department of Chemistry, Wesleyan University, Middletown, CT, 06459, United States
| | - Joy M Cote
- Department of Chemistry, Wesleyan University, Middletown, CT, 06459, United States
| | - Erika A Taylor
- Department of Chemistry, Wesleyan University, Middletown, CT, 06459, United States.
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34
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Ramírez AS, Boilevin J, Mehdipour AR, Hummer G, Darbre T, Reymond JL, Locher KP. Structural basis of the molecular ruler mechanism of a bacterial glycosyltransferase. Nat Commun 2018; 9:445. [PMID: 29386647 PMCID: PMC5792488 DOI: 10.1038/s41467-018-02880-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Accepted: 01/02/2018] [Indexed: 11/09/2022] Open
Abstract
The membrane-associated, processive and retaining glycosyltransferase PglH from Campylobacter jejuni is part of the biosynthetic pathway of the lipid-linked oligosaccharide (LLO) that serves as the glycan donor in bacterial protein N-glycosylation. Using an unknown counting mechanism, PglH catalyzes the transfer of exactly three α1,4 N-acetylgalactosamine (GalNAc) units to the growing LLO precursor, GalNAc-α1,4-GalNAc-α1,3-Bac-α1-PP-undecaprenyl. Here, we present crystal structures of PglH in three distinct states, including a binary complex with UDP-GalNAc and two ternary complexes containing a chemo-enzymatically generated LLO analog and either UDP or synthetic, nonhydrolyzable UDP-CH2-GalNAc. PglH contains an amphipathic helix ("ruler helix") that has a dual role of facilitating membrane attachment and glycan counting. The ruler helix contains three positively charged side chains that can bind the pyrophosphate group of the LLO substrate and thus limit the addition of GalNAc units to three. These results, combined with molecular dynamics simulations, provide the mechanism of glycan counting by PglH.
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Affiliation(s)
- Ana S Ramírez
- Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule (ETH), CH-8093, Zürich, Switzerland
| | - Jérémy Boilevin
- Department of Chemistry and Biochemistry, University of Berne, CH-3012, Berne, Switzerland
| | - Ahmad Reza Mehdipour
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, DE-60438, Frankfurt, Germany
| | - Gerhard Hummer
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, DE-60438, Frankfurt, Germany.,Institute of Biophysics, Goethe University, DE-60438, Frankfurt, Germany
| | - Tamis Darbre
- Department of Chemistry and Biochemistry, University of Berne, CH-3012, Berne, Switzerland
| | - Jean-Louis Reymond
- Department of Chemistry and Biochemistry, University of Berne, CH-3012, Berne, Switzerland
| | - Kaspar P Locher
- Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule (ETH), CH-8093, Zürich, Switzerland.
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35
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Bohl HO, Shi K, Lee JK, Aihara H. Crystal structure of lipid A disaccharide synthase LpxB from Escherichia coli. Nat Commun 2018; 9:377. [PMID: 29371662 PMCID: PMC5785501 DOI: 10.1038/s41467-017-02712-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 12/20/2017] [Indexed: 11/23/2022] Open
Abstract
Most Gram-negative bacteria are surrounded by a glycolipid called lipopolysaccharide (LPS), which forms a barrier to hydrophobic toxins and, in pathogenic bacteria, is a virulence factor. During LPS biosynthesis, a membrane-associated glycosyltransferase (LpxB) forms a tetra-acylated disaccharide that is further acylated to form the membrane anchor moiety of LPS. Here we solve the structure of a soluble and catalytically competent LpxB by X-ray crystallography. The structure reveals that LpxB has a glycosyltransferase-B family fold but with a highly intertwined, C-terminally swapped dimer comprising four domains. We identify key catalytic residues with a product, UDP, bound in the active site, as well as clusters of hydrophobic residues that likely mediate productive membrane association or capture of lipidic substrates. These studies provide the basis for rational design of antibiotics targeting a crucial step in LPS biosynthesis.
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Affiliation(s)
- Heather O Bohl
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Twin Cities, Minneapolis, MN, 55455, USA
| | - Ke Shi
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Twin Cities, Minneapolis, MN, 55455, USA
| | - John K Lee
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Twin Cities, Minneapolis, MN, 55455, USA
- Bristol-Myers Squibb, Redwood City, CA, 94063, USA
| | - Hideki Aihara
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Twin Cities, Minneapolis, MN, 55455, USA.
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36
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Kenyon JJ, Kasimova AA, Notaro A, Arbatsky NP, Speciale I, Shashkov AS, De Castro C, Hall RM, Knirel YA. Acinetobacter baumannii K13 and K73 capsular polysaccharides differ only in K-unit side branches of novel non-2-ulosonic acids: di- N -acetylated forms of either acinetaminic acid or 8-epiacinetaminic acid. Carbohydr Res 2017; 452:149-155. [DOI: 10.1016/j.carres.2017.10.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 10/13/2017] [Accepted: 10/13/2017] [Indexed: 11/30/2022]
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37
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Cote JM, Taylor EA. The Glycosyltransferases of LPS Core: A Review of Four Heptosyltransferase Enzymes in Context. Int J Mol Sci 2017; 18:E2256. [PMID: 29077008 PMCID: PMC5713226 DOI: 10.3390/ijms18112256] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 10/23/2017] [Accepted: 10/24/2017] [Indexed: 12/15/2022] Open
Abstract
Bacterial antibiotic resistance is a rapidly expanding problem in the world today. Functionalization of the outer membrane of Gram-negative bacteria provides protection from extracellular antimicrobials, and serves as an innate resistance mechanism. Lipopolysaccharides (LPS) are a major cell-surface component of Gram-negative bacteria that contribute to protecting the bacterium from extracellular threats. LPS is biosynthesized by the sequential addition of sugar moieties by a number of glycosyltransferases (GTs). Heptosyltransferases catalyze the addition of multiple heptose sugars to form the core region of LPS; there are at most four heptosyltransferases found in all Gram-negative bacteria. The most studied of the four is HepI. Cells deficient in HepI display a truncated LPS on their cell surface, causing them to be more susceptible to hydrophobic antibiotics. HepI-IV are all structurally similar members of the GT-B structural family, a class of enzymes that have been found to be highly dynamic. Understanding conformational changes of heptosyltransferases are important to efficiently inhibiting them, but also contributing to the understanding of all GT-B enzymes. Finding new and smarter methods to inhibit bacterial growth is crucial, and the Heptosyltransferases may provide an important model for how to inhibit many GT-B enzymes.
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Affiliation(s)
- Joy M Cote
- Department of Chemistry, Wesleyan University, Middletown, CT 06459, USA.
| | - Erika A Taylor
- Department of Chemistry, Wesleyan University, Middletown, CT 06459, USA.
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38
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Identification and biochemical characterization of WbwB, a novel UDP-Gal: Neu5Ac-R α1,4-galactosyltransferase from the intestinal pathogen Escherichia coli serotype O104. Glycoconj J 2017; 35:65-76. [PMID: 29063990 DOI: 10.1007/s10719-017-9799-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 09/11/2017] [Accepted: 09/13/2017] [Indexed: 02/08/2023]
Abstract
The intestinal pathogen Escherichia coli serotype O104:H4 (ECO104) can cause bloody diarrhea and haemolytic uremic syndrome. The ECO104 O antigen has the unique repeating unit structure [4Galα1-4Neu5,7,9Ac3α2-3Galβ1-3GalNAcβ1-], which includes the mammalian sialyl-T antigen as an internal structure. Previously, we identified WbwC from ECO104 as the β3Gal-transferase that synthesizes the T antigen, and showed that α3-sialyl-transferase WbwA transfers sialic acid to the T antigen. Here we identify the wbwB gene product as a unique α1,4-Gal-transferase WbwB that transfers Gal from UDP-Gal to the terminal sialic acid residue of Neu5Acα2-3Galβ1-3GalNAcα-diphosphate-lipid acceptor. NMR analysis of the WbwB enzyme reaction product indicated that Galα1-4Neu5Acα2-3Galβ1-3GalNAcα-diphosphate-lipid was synthesized. WbwB from ECO104 has a unique acceptor specificity for terminal sialic acid as well as the diphosphate group in the acceptor. The characterization studies showed that WbwB does not require divalent metal ion as a cofactor. Mutagenesis identified Lys243 within an RKR motif and both Glu315 and Glu323 of the fourth EX7E motif as essential for the activity. WbwB is the final glycosyltransferase in the biosynthesis pathway of the ECO104 antigen repeating unit. This work contributes to knowledge of the biosynthesis of bacterial virulence factors.
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39
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A front-face 'SNi synthase' engineered from a retaining 'double-SN2' hydrolase. Nat Chem Biol 2017; 13:874-881. [DOI: 10.1038/nchembio.2394] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 03/08/2017] [Indexed: 01/13/2023]
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40
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Cote JM, Ramirez-Mondragon CA, Siegel ZS, Czyzyk DJ, Gao J, Sham YY, Mukerji I, Taylor EA. The Stories Tryptophans Tell: Exploring Protein Dynamics of Heptosyltransferase I from Escherichia coli. Biochemistry 2017; 56:886-895. [PMID: 28098447 DOI: 10.1021/acs.biochem.6b00850] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Heptosyltransferase I (HepI) catalyzes the addition of l-glycero-β-d-manno-heptose to Kdo2-Lipid A, as part of the biosynthesis of the core region of lipopolysaccharide (LPS). Gram-negative bacteria with gene knockouts of HepI have reduced virulence and enhanced susceptibility to hydrophobic antibiotics, making the design of inhibitors of HepI of interest. Because HepI protein dynamics are partially rate-limiting, disruption of protein dynamics might provide a new strategy for inhibiting HepI. Discerning the global mechanism of HepI is anticipated to aid development of inhibitors of LPS biosynthesis. Herein, dynamic protein rearrangements involved in the HepI catalytic cycle were probed by combining mutagenesis with intrinsic tryptophan fluorescence and circular dichroism analyses. Using wild-type and mutant forms of HepI, multiple dynamic regions were identified via changes in Trp fluorescence. Interestingly, Trp residues (Trp199 and Trp217) in the C-terminal domain (which binds ADP-heptose) are in a more hydrophobic environment upon binding of ODLA to the N-terminal domain. These residues are adjacent to the ADP-heptose binding site (with Trp217 in van der Waals contact with the adenine ring of ADP-heptose), suggesting that the two binding sites interact to report on the occupancy state of the enzyme. ODLA binding was also accompanied by a significant stabilization of HepI (heating to 95 °C fails to denature the protein when it is in the presence of ODLA). These results suggest that conformational rearrangements, from an induced fit model of substrate binding to HepI, are important for catalysis, and the disruption of these conformational dynamics may serve as a novel mechanism for inhibiting this and other glycosyltransferase enzymes.
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Affiliation(s)
- Joy M Cote
- Department of Chemistry, Wesleyan University , Middletown, Connecticut 06459, United States
| | | | - Zarek S Siegel
- Department of Chemistry, Wesleyan University , Middletown, Connecticut 06459, United States
| | - Daniel J Czyzyk
- Department of Chemistry, Wesleyan University , Middletown, Connecticut 06459, United States
| | | | | | - Ishita Mukerji
- Molecular Biophysics Program, Department of Molecular Biology and Biochemistry, Wesleyan University , Middletown, Connecticut 06459, United States
| | - Erika A Taylor
- Department of Chemistry, Wesleyan University , Middletown, Connecticut 06459, United States
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41
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Blanco Capurro JI, Hopkins CW, Pierdominici Sottile G, González Lebrero MC, Roitberg AE, Marti MA. Theoretical Insights into the Reaction and Inhibition Mechanism of Metal-Independent Retaining Glycosyltransferase Responsible for Mycothiol Biosynthesis. J Phys Chem B 2017; 121:471-478. [PMID: 27935720 DOI: 10.1021/acs.jpcb.6b10130] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Understanding enzymatic reactions with atomic resolution has proven in recent years to be of tremendous interest for biochemical research, and thus, the use of QM/MM methods for the study of reaction mechanisms is experiencing a continuous growth. Glycosyltransferases (GTs) catalyze the formation of glycosidic bonds, and are important for many biotechnological purposes, including drug targeting. Their reaction product may result with only one of the two possible stereochemical outcomes for the reacting anomeric center, and therefore, they are classified as either inverting or retaining GTs. While the inverting GT reaction mechanism has been widely studied, the retaining GT mechanism has always been controversial and several questions remain open to this day. In this work, we take advantage of our recent GPU implementation of a pure QM(DFT-PBE)/MM approach to explore the reaction and inhibition mechanism of MshA, a key retaining GT responsible for the first step of mycothiol biosynthesis, a low weight thiol compound found in pathogens like Mycobacterium tuberculosis that is essential for its survival under oxidative stress conditions. Our results show that the reaction proceeds via a front-side SNi-like concerted reaction mechanism (DNAN in IUPAC nomenclature) and has a 17.5 kcal/mol free energy barrier, which is in remarkable agreement with experimental data. Detailed analysis shows that the key reaction step is the diphosphate leaving group dissociation, leading to an oxocarbenium-ion-like transition state. In contrast, fluorinated substrate analogues increase the reaction barrier significantly, rendering the enzyme effectively inactive. Detailed analysis of the electronic structure along the reaction suggests that this particular inhibition mechanism is associated with fluorine's high electronegative nature, which hinders phosphate release and proper stabilization of the transition state.
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Affiliation(s)
- Juan I Blanco Capurro
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria , Intendente Guiraldes 2160, C1428EGA, Ciudad Autónoma de Buenos Aires, Argentina.,Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), CONICET, Ciudad Universitaria , Intendente Guiraldes 2160, C1428EGA, Ciudad Autónoma de Buenos Aires, Argentina
| | - Chad W Hopkins
- Department of Physics, University of Florida , Gainesville, Florida 32611, United States
| | - Gustavo Pierdominici Sottile
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes , Sáenz Peña 352, Bernal B1876BXD, Argentina
| | - Mariano C González Lebrero
- Departamento de Quimica Inorgánica, Anlı́tica y Quı́mica Fı́sica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria , Intendente Guiraldes 2160, C1428EGA, Ciudad Autónoma de Buenos Aires, Argentina.,Insituto de Quimica Inorgánica, Materiales Ambiente y Energı́a (INQUIMAE), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria , Intendente Guiraldes 2160, C1428EGA, Ciudad Autónoma de Buenos Aires, Argentina
| | - Adrian E Roitberg
- Department of Chemistry, University of Florida , Gainesville, Florida 32611, United States
| | - Marcelo A Marti
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria , Intendente Guiraldes 2160, C1428EGA, Ciudad Autónoma de Buenos Aires, Argentina.,Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), CONICET, Ciudad Universitaria , Intendente Guiraldes 2160, C1428EGA, Ciudad Autónoma de Buenos Aires, Argentina
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42
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Guo Y, Wang L, Guo J, Gu G, Guo Z. Biochemical studies of inositol N-acetylglucosaminyltransferase involved in mycothiol biosynthesis in Corynebacterium diphtheria. Org Biomol Chem 2017; 15:3775-3782. [DOI: 10.1039/c7ob00555e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
First-time expression, isolation, biochemical characterization, and mutagenesis studies of a MshA from Corynebacterium diphtheria involved in its mycothiol biosynthesis.
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Affiliation(s)
- Yuchuan Guo
- National Glycoengineering Research Center and Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology
- Shandong University
- Jinan 250100
- China
- Department of Chemistry
| | - Lizhen Wang
- National Glycoengineering Research Center and Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology
- Shandong University
- Jinan 250100
- China
| | - Jiatong Guo
- Department of Chemistry
- University of Florida
- Gainesville
- USA
| | - Guofeng Gu
- National Glycoengineering Research Center and Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology
- Shandong University
- Jinan 250100
- China
| | - Zhongwu Guo
- Department of Chemistry
- University of Florida
- Gainesville
- USA
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43
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Sayer LH, Florence GJ, Smith TK. A biocatalytic approach towards the stereoselective synthesis of protected inositols. REACT CHEM ENG 2017. [DOI: 10.1039/c6re00175k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Immobilized TbINO1 produces >400 mg of chiral inositol 1-phosphate in a biocatalytic flow process.
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Affiliation(s)
- L. H. Sayer
- Biomedical Science Research Complex
- Schools of Chemistry and Biology
- University of St Andrews
- St Andrews
- UK
| | - G. J. Florence
- Biomedical Science Research Complex
- Schools of Chemistry and Biology
- University of St Andrews
- St Andrews
- UK
| | - T. K. Smith
- Biomedical Science Research Complex
- Schools of Chemistry and Biology
- University of St Andrews
- St Andrews
- UK
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Winchell KR, Egeler PW, VanDuinen AJ, Jackson LB, Karpen ME, Cook PD. A Structural, Functional, and Computational Analysis of BshA, the First Enzyme in the Bacillithiol Biosynthesis Pathway. Biochemistry 2016; 55:4654-65. [PMID: 27454321 PMCID: PMC5954418 DOI: 10.1021/acs.biochem.6b00472] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Bacillithiol is a compound produced by several Gram-positive bacterial species, including the human pathogens Staphylococcus aureus and Bacillus anthracis. It is involved in maintaining cellular redox balance as well as the destruction of reactive oxygen species and harmful xenobiotic agents, including the antibiotic fosfomycin. BshA, BshB, and BshC are the enzymes involved in bacillithiol biosynthesis. BshA is a retaining glycosyltransferase responsible for the first committed step in bacillithiol production, namely the addition of N-acetylglucosamine to l-malate. Retaining glycosyltransferases like BshA are proposed to utilize an SNi-like reaction mechanism in which leaving group departure and nucleophilic attack occur on the same face of the hexose. However, significant questions regarding the details of how BshA and similar enzymes accommodate their substrates and facilitate catalysis persist. Here we report X-ray crystallographic structures of BshA from Bacillus subtilis 168 bound with UMP and/or GlcNAc-mal at resolutions of 2.15 and 2.02 Å, respectively. These ligand-bound structures, along with our functional and computational studies, provide clearer insight into how BshA and other retaining GT-B glycosyltransferases operate, corroborating the substrate-assisted, SNi-like reaction mechanism. The analyses presented herein can serve as the basis for the design of inhibitors capable of preventing bacillithiol production and, subsequently, help combat resistance to fosfomycin in various pathogenic Gram-positive microorganisms.
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Affiliation(s)
- Kelsey R. Winchell
- Department of Chemistry, Grand Valley State University, Allendale, Michigan, 49401, United States
| | - Paul W. Egeler
- Department of Chemistry, Grand Valley State University, Allendale, Michigan, 49401, United States
| | - Andrew J. VanDuinen
- Department of Cell and Molecular Biology, Grand Valley State University, Allendale, Michigan, 49401, United States
| | - Luke B. Jackson
- Department of Chemistry, Grand Valley State University, Allendale, Michigan, 49401, United States
| | - Mary E. Karpen
- Department of Chemistry, Grand Valley State University, Allendale, Michigan, 49401, United States
| | - Paul D. Cook
- Department of Chemistry, Grand Valley State University, Allendale, Michigan, 49401, United States
- Department of Cell and Molecular Biology, Grand Valley State University, Allendale, Michigan, 49401, United States
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Higuchi Y, Yoshinaga S, Yoritsune KI, Tateno H, Hirabayashi J, Nakakita SI, Kanekiyo M, Kakuta Y, Takegawa K. A rationally engineered yeast pyruvyltransferase Pvg1p introduces sialylation-like properties in neo-human-type complex oligosaccharide. Sci Rep 2016; 6:26349. [PMID: 27194449 PMCID: PMC4872226 DOI: 10.1038/srep26349] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 04/29/2016] [Indexed: 11/09/2022] Open
Abstract
Pyruvylation onto the terminus of oligosaccharide, widely seen from prokaryote to eukaryote, confers negative charges on the cell surface and seems to be functionally similar to sialylation, which is found at the end of human-type complex oligosaccharide. However, detailed molecular mechanisms underlying pyruvylation have not been clarified well. Here, we first determined the crystal structure of fission yeast pyruvyltransferase Pvg1p at a resolution of 2.46 Å. Subsequently, by combining molecular modeling with mutational analysis of active site residues, we obtained a Pvg1p mutant (Pvg1p(H168C)) that efficiently transferred pyruvyl moiety onto a human-type complex glycopeptide. The resultant pyruvylated human-type complex glycopeptide recognized similar lectins on lectin arrays as the α2,6-sialyl glycopeptides. This newly-generated pyruvylation of human-type complex oligosaccharides would provide a novel method for glyco-bioengineering.
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Affiliation(s)
- Yujiro Higuchi
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581, Japan
| | - Sho Yoshinaga
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581, Japan
| | - Ken-Ichi Yoritsune
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581, Japan
| | - Hiroaki Tateno
- Biotechnology Research Institute for Drug Discovery, National Institute of Advanced Industrial Science and Technology, Central-2, 1-1-1, Umezono, Tsukuba, Ibaraki 305-8568, Japan
| | - Jun Hirabayashi
- Biotechnology Research Institute for Drug Discovery, National Institute of Advanced Industrial Science and Technology, Central-2, 1-1-1, Umezono, Tsukuba, Ibaraki 305-8568, Japan
| | - Shin-Ichi Nakakita
- Department of Functional Glycomics, Life Science Research Center, Kagawa University, Miki-cho, Kagawa 761-0793, Japan
| | - Miho Kanekiyo
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581, Japan
| | - Yoshimitsu Kakuta
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581, Japan
| | - Kaoru Takegawa
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581, Japan
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Affiliation(s)
- Fengzhi Li
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, 300071 China.,College of Life Sciences, Nankai University, Tianjin, 300071 China
| | - Siwei Li
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
| | - Xiaofen Liu
- College of Life Sciences, Nankai University, Tianjin, 300071 China
| | - Xue Yang
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, 300071 China
| | - Peng Wang
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, 300071 China
| | - Yuequan Shen
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, 300071 China.,College of Life Sciences, Nankai University, Tianjin, 300071 China.,Synergetic Innovation Center of Chemical Science and Engineering, Tianjin, 300071 China
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Salinas SR, Petruk AA, Brukman NG, Bianco MI, Jacobs M, Marti MA, Ielpi L. Binding of the substrate UDP-glucuronic acid induces conformational changes in the xanthan gum glucuronosyltransferase. Protein Eng Des Sel 2016; 29:197-207. [PMID: 27099353 DOI: 10.1093/protein/gzw007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 03/02/2016] [Indexed: 01/24/2023] Open
Abstract
GumK is a membrane-associated glucuronosyltransferase of Xanthomonas campestris that is involved in xanthan gum biosynthesis. GumK belongs to the inverting GT-B superfamily and catalyzes the transfer of a glucuronic acid (GlcA) residue from uridine diphosphate (UDP)-GlcA (UDP-GlcA) to a lipid-PP-trisaccharide embedded in the membrane of the bacteria. The structure of GumK was previously described in its apo- and UDP-bound forms, with no significant conformational differences being observed. Here, we study the behavior of GumK toward its donor substrate UDP-GlcA. Turbidity measurements revealed that the interaction of GumK with UDP-GlcA produces aggregation of protein molecules under specific conditions. Moreover, limited proteolysis assays demonstrated protection of enzymatic digestion when UDP-GlcA is present, and this protection is promoted by substrate binding. Circular dichroism spectroscopy also revealed changes in the GumK tertiary structure after UDP-GlcA addition. According to the obtained emission fluorescence results, we suggest the possibility of exposure of hydrophobic residues upon UDP-GlcA binding. We present in silico-built models of GumK complexed with UDP-GlcA as well as its analogs UDP-glucose and UDP-galacturonic acid. Through molecular dynamics simulations, we also show that a relative movement between the domains appears to be specific and to be triggered by UDP-GlcA. The results presented here strongly suggest that GumK undergoes a conformational change upon donor substrate binding, likely bringing the two Rossmann fold domains closer together and triggering a change in the N-terminal domain, with consequent generation of the acceptor substrate binding site.
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Affiliation(s)
- S R Salinas
- Laboratory of Bacterial Genetics, Fundación Instituto Leloir, IIBBA-CONICET, Av. Patricias Argentinas 435, C1405BWE Buenos Aires, Argentina
| | - A A Petruk
- Departamento de Química Inorgánica, Analítica, y Química Física/INQUIMAE CONICET, Córdoba, Argentina
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, C1428EHA Buenos Aires, Argentina
| | - N G Brukman
- Laboratory of Bacterial Genetics, Fundación Instituto Leloir, IIBBA-CONICET, Av. Patricias Argentinas 435, C1405BWE Buenos Aires, Argentina
| | - M I Bianco
- Laboratory of Bacterial Genetics, Fundación Instituto Leloir, IIBBA-CONICET, Av. Patricias Argentinas 435, C1405BWE Buenos Aires, Argentina
| | - M Jacobs
- Laboratory of Bacterial Genetics, Fundación Instituto Leloir, IIBBA-CONICET, Av. Patricias Argentinas 435, C1405BWE Buenos Aires, Argentina
| | - M A Marti
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, C1428EHA Buenos Aires, Argentina
| | - L Ielpi
- Laboratory of Bacterial Genetics, Fundación Instituto Leloir, IIBBA-CONICET, Av. Patricias Argentinas 435, C1405BWE Buenos Aires, Argentina
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Mechanism of a cytosolic O-glycosyltransferase essential for the synthesis of a bacterial adhesion protein. Proc Natl Acad Sci U S A 2016; 113:E1190-9. [PMID: 26884191 DOI: 10.1073/pnas.1600494113] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
O-glycosylation of Ser and Thr residues is an important process in all organisms, which is only poorly understood. Such modification is required for the export and function of adhesin proteins that mediate the attachment of pathogenic Gram-positive bacteria to host cells. Here, we have analyzed the mechanism by which the cytosolic O-glycosyltransferase GtfA/B of Streptococcus gordonii modifies the Ser/Thr-rich repeats of adhesin. The enzyme is a tetramer containing two molecules each of GtfA and GtfB. The two subunits have the same fold, but only GtfA contains an active site, whereas GtfB provides the primary binding site for adhesin. During a first phase of glycosylation, the conformation of GtfB is restrained by GtfA to bind substrate with unmodified Ser/Thr residues. In a slow second phase, GtfB recognizes residues that are already modified with N-acetylglucosamine, likely by converting into a relaxed conformation in which one interface with GtfA is broken. These results explain how the glycosyltransferase modifies a progressively changing substrate molecule.
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Wang XP, Jiang YL, Dai YN, Cheng W, Chen Y, Zhou CZ. Structural and enzymatic analyses of a glucosyltransferase Alr3699/HepE involved in Anabaena heterocyst envelop polysaccharide biosynthesis. Glycobiology 2015; 26:520-31. [PMID: 26692049 DOI: 10.1093/glycob/cwv167] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 12/13/2015] [Indexed: 01/18/2023] Open
Abstract
Formation of the heterocyst envelope polysaccharide (HEP) is a key process for cyanobacterial heterocyst differentiation. The maturation of HEP in Anabaena sp. strain PCC 7120 is controlled by a gene cluster termed HEP island in addition to an operon alr3698-alr3699, which encodes two putative proteins termed Alr3698/HepD and Alr3699/HepE. Here we report the crystal structures of HepE in the apo-form and three complex forms that bind to UDP-glucose (UDPG), UDP&glucose, and UDP, respectively. The overall structure of HepE displays a typical GT-B fold of glycosyltransferases, comprising two separate β/α/β Rossmann-fold domains that form an inter-domain substrate-binding crevice. Structural analyses combined with enzymatic assays indicate that HepE is a glucosyltransferase using UDPG as a sugar donor. Further site-directed mutageneses enable us to assign the key residues that stabilize the sugar donor and putative acceptor. Based on the comparative structural analyses, we propose a putative catalytic cycle of HepE, which undergoes "open-closed-open" conformational changes upon binding to the substrates and release of products. These findings provide structural and catalytic insights into the first enzyme involved in the HEP biosynthesis pathway.
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Affiliation(s)
- Xue-Ping Wang
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, People's Republic of China
| | - Yong-Liang Jiang
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, People's Republic of China
| | - Ya-Nan Dai
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, People's Republic of China
| | - Wang Cheng
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, People's Republic of China
| | - Yuxing Chen
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, People's Republic of China
| | - Cong-Zhao Zhou
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, People's Republic of China
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Schmölzer K, Gutmann A, Diricks M, Desmet T, Nidetzky B. Sucrose synthase: A unique glycosyltransferase for biocatalytic glycosylation process development. Biotechnol Adv 2015; 34:88-111. [PMID: 26657050 DOI: 10.1016/j.biotechadv.2015.11.003] [Citation(s) in RCA: 133] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 11/18/2015] [Accepted: 11/24/2015] [Indexed: 01/24/2023]
Abstract
Sucrose synthase (SuSy, EC 2.4.1.13) is a glycosyltransferase (GT) long known from plants and more recently discovered in bacteria. The enzyme catalyzes the reversible transfer of a glucosyl moiety between fructose and a nucleoside diphosphate (NDP) (sucrose+NDP↔NDP-glucose+fructose). The equilibrium for sucrose conversion is pH dependent, and pH values between 5.5 and 7.5 promote NDP-glucose formation. The conversion of a bulk chemical to high-priced NDP-glucose in a one-step reaction provides the key aspect for industrial interest. NDP-sugars are important as such and as key intermediates for glycosylation reactions by highly selective Leloir GTs. SuSy has gained renewed interest as industrially attractive biocatalyst, due to substantial scientific progresses achieved in the last few years. These include biochemical characterization of bacterial SuSys, overproduction of recombinant SuSys, structural information useful for design of tailor-made catalysts, and development of one-pot SuSy-GT cascade reactions for production of several relevant glycosides. These advances could pave the way for the application of Leloir GTs to be used in cost-effective processes. This review provides a framework for application requirements, focusing on catalytic properties, heterologous enzyme production and reaction engineering. The potential of SuSy biocatalysis will be presented based on various biotechnological applications: NDP-sugar synthesis; sucrose analog synthesis; glycoside synthesis by SuSy-GT cascade reactions.
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Affiliation(s)
- Katharina Schmölzer
- Austrian Centre of Industrial Biotechnology, Petersgasse 14, 8010 Graz, Austria.
| | - Alexander Gutmann
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Petersgasse 12/I, 8010 Graz, Austria.
| | - Margo Diricks
- Centre for Industrial Biotechnology and Biocatalysis, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium.
| | - Tom Desmet
- Centre for Industrial Biotechnology and Biocatalysis, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium.
| | - Bernd Nidetzky
- Austrian Centre of Industrial Biotechnology, Petersgasse 14, 8010 Graz, Austria; Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Petersgasse 12/I, 8010 Graz, Austria.
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