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Álvarez-Lugo A, Becerra A. The Fate of Duplicated Enzymes in Prokaryotes: The Case of Isomerases. J Mol Evol 2023; 91:76-92. [PMID: 36580111 DOI: 10.1007/s00239-022-10085-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 12/16/2022] [Indexed: 12/30/2022]
Abstract
The isomerases are a unique enzymatic class of enzymes that carry out a great diversity of chemical reactions at the intramolecular level. This class comprises about 300 members, most of which are involved in carbohydrate and terpenoid/polyketide metabolism. Along with oxidoreductases and translocases, isomerases are one of the classes with the highest ratio of paralogous enzymes. Due to its relatively small number of members, it is plausible to explore it in greater detail to identify specific cases of gene duplication. Here, we present an analysis at the level of individual isomerases and identify different members that seem to be involved in duplication events in prokaryotes. As was suggested in a previous study, there is no homogeneous distribution of paralogs, but rather they accumulate into a few subcategories, some of which differ between Archaea and Bacteria. As expected, the metabolic processes with more paralogous isomerases have to do with carbohydrate metabolism but also with RNA modification (a particular case involving an rRNA-modifying isomerase is thoroughly discussed and analyzed in detail). Overall, our findings suggest that the most common fate for paralogous enzymes is the retention of the original enzymatic function, either associated with a dosage effect or with differential expression in response to changing environments, followed by subfunctionalization and, to a much lesser degree, neofunctionalization, which is consistent with what has been reported elsewhere.
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Affiliation(s)
- Alejandro Álvarez-Lugo
- Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, Mexico City, México.,Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, México
| | - Arturo Becerra
- Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, México.
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2
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Borg AJE, Esquivias O, Coines J, Rovira C, Nidetzky B. Enzymatische C4-Epimerisierung von UDP-Glucuronsäure: präzise gesteuerte Rotation eines transienten 4-Ketointermediats für eine invertierende Reaktion ohne Decarboxylierung. ANGEWANDTE CHEMIE (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 135:e202211937. [PMID: 38515538 PMCID: PMC10952283 DOI: 10.1002/ange.202211937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Indexed: 03/23/2024]
Abstract
AbstractUDP‐Glucuronsäure(UDP‐GlcA)‐4‐Epimerase repräsentiert eine wichtige Fragestellung in der Enzymkatalyse: die Balance zwischen konformativer Flexibilität und genauer Positionierung. Das Enzym koordiniert die C4‐Oxidation des Substrats durch NAD+ mit der Rotation eines leicht decarboxylierbaren β‐Ketosäure‐Intermediats im aktiven Zentrum zur Ermöglichung der stereoinvertierenden Reduktion der Ketogruppe durch NADH. Wir zeigen hier die nur schwer erfassbare Rotationskoordinate des 4‐Ketointermediats. Distorsion des Zuckerrings in eine Boot‐Konformation erzeugt torsionale Mobilität in der Bindungstasche des Enzyms. Die Endpunkte der Rotation zeigen den 4‐Ketozucker in einer unverformten 4C1‐Sesselkonformation. Die äquatorial positionierte Carboxylatgruppe ist ungünstig für die 4‐Ketozucker‐Decarboxylierung. Varianten der Epimerase zeigen Decarboxylierung, wenn sie die Bindung mit der Carboxylatgruppe im entgegengesetzten Rotationsisomer des Substrats entfernen. R185A/D‐Substitutionen wandeln die Epimerase in UDP‐Xylose‐Synthasen um, welche UDP‐GlcA in stereospezifischen, konfigurationserhaltenden Reaktionen decarboxylieren.
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Affiliation(s)
- Annika J. E. Borg
- Institut für Biotechnologie und BioprozesstechnikTechnische Universität GrazPetersgasse 12/18010GrazÖsterreich
| | - Oriol Esquivias
- Department of Inorganic and Organic Chemistry (Section of Organic Chemistry)Institute of Computational and Theoretical Chemistry (IQTCUB)Martí i Franquès 108028BarcelonaSpanien
| | - Joan Coines
- Department of Inorganic and Organic Chemistry (Section of Organic Chemistry)Institute of Computational and Theoretical Chemistry (IQTCUB)Martí i Franquès 108028BarcelonaSpanien
- Derzeitige Adresse: Nostrum BiodiscoveryAv. De Josep Tarradellas, 8–1008029BarcelonaSpanien
| | - Carme Rovira
- Department of Inorganic and Organic Chemistry (Section of Organic Chemistry)Institute of Computational and Theoretical Chemistry (IQTCUB)Martí i Franquès 108028BarcelonaSpanien
- Institució Catalana de Recerca i Estudis Avançats (ICREA)Passeig Lluís Companys, 2308010BarcelonaSpanien
| | - Bernd Nidetzky
- Institut für Biotechnologie und BioprozesstechnikTechnische Universität GrazPetersgasse 12/18010GrazÖsterreich
- Austrian Center of Industrial Biotechnology (acib)Krenngasse 378010GrazÖsterreich
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3
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Borg AJE, Esquivias O, Coines J, Rovira C, Nidetzky B. Enzymatic C4-Epimerization of UDP-Glucuronic Acid: Precisely Steered Rotation of a Transient 4-Keto Intermediate for an Inverted Reaction without Decarboxylation. Angew Chem Int Ed Engl 2023; 62:e202211937. [PMID: 36308301 PMCID: PMC10107529 DOI: 10.1002/anie.202211937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 10/03/2022] [Accepted: 10/26/2022] [Indexed: 11/06/2022]
Abstract
UDP-glucuronic acid (UDP-GlcA) 4-epimerase illustrates an important problem regarding enzyme catalysis: balancing conformational flexibility with precise positioning. The enzyme coordinates the C4-oxidation of the substrate by NAD+ and rotation of a decarboxylation-prone β-keto acid intermediate in the active site, enabling stereoinverting reduction of the keto group by NADH. We reveal the elusive rotational landscape of the 4-keto intermediate. Distortion of the sugar ring into boat conformations induces torsional mobility in the enzyme's binding pocket. The rotational endpoints show that the 4-keto sugar has an undistorted 4 C1 chair conformation. The equatorially placed carboxylate group disfavors decarboxylation of the 4-keto sugar. Epimerase variants lead to decarboxylation upon removal of the binding interactions with the carboxylate group in the opposite rotational isomer of the substrate. Substitutions R185A/D convert the epimerase into UDP-xylose synthases that decarboxylate UDP-GlcA in stereospecific, configuration-retaining reactions.
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Affiliation(s)
- Annika J E Borg
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 12/1, 8010, Graz, Austria
| | - Oriol Esquivias
- Department of Inorganic and Organic Chemistry (Section of Organic Chemistry), Institute of Computational and Theoretical Chemistry (IQTCUB), Martí i Franquès 1, 08028, Barcelona, Spain
| | - Joan Coines
- Department of Inorganic and Organic Chemistry (Section of Organic Chemistry), Institute of Computational and Theoretical Chemistry (IQTCUB), Martí i Franquès 1, 08028, Barcelona, Spain.,Present address: Nostrum Biodiscovery, Av. De Josep Tarradellas, 8-10, 08029, Barcelona, Spain
| | - Carme Rovira
- Department of Inorganic and Organic Chemistry (Section of Organic Chemistry), Institute of Computational and Theoretical Chemistry (IQTCUB), Martí i Franquès 1, 08028, Barcelona, Spain.,Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys, 23, 08010, Barcelona, Spain
| | - Bernd Nidetzky
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 12/1, 8010, Graz, Austria.,Austrian Center of Industrial Biotechnology (acib), Krenngasse 37, 8010, Graz, Austria
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4
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Zeng Z, Zeng X, Guo Y, Wu Z, Cai Z, Pan D. Determining the Role of UTP-Glucose-1-Phosphate Uridylyltransferase (GalU) in Improving the Resistance of Lactobacillus acidophilus NCFM to Freeze-Drying. Foods 2022; 11:foods11121719. [PMID: 35741917 PMCID: PMC9223153 DOI: 10.3390/foods11121719] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 06/05/2022] [Accepted: 06/06/2022] [Indexed: 11/23/2022] Open
Abstract
Lactobacillus acidophilus NCFM is widely used in the fermentation industry; using it as a freeze-dried powder can greatly reduce the costs associated with packaging and transportation, and even prolong the storage period. Previously published research has reported that the expression of galU (EC: 2.7.7.9) is significantly increased as a result of freezing and drying. Herein, we aimed to explore how galU plays an important role in improving the resistance of Lactobacillus acidophilus NCFM to freeze-drying. For this study, galU was first knocked out and then re-expressed in L. acidophilus NCFM to functionally characterize its role in the pertinent metabolic pathways. The knockout strain ΔgalU showed lactose/galactose deficiency and displayed irregular cell morphology, shortened cell length, thin and rough capsules, and abnormal cell division, and the progeny could not be separated. In the re-expression strain pgalU, these inhibited pathways were restored; moreover, the pgalU cells showed a strengthened cell wall and capsule, which enhanced their resistance to adverse environments. The pgalU cells showed GalU activity that was 229% higher than that shown by the wild-type strain, and the freeze-drying survival rate was 84%, this being 4.7 times higher than that of the wild-type strain. To summarize, expression of the galU gene can significantly enhance gene expression in galactose metabolic pathway and make the strain form a stronger cell wall and cell capsule and enhance the resistance of the bacteria to an adverse external environment, to improve the freeze-drying survival rate of L. acidophilus NCFM.
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Affiliation(s)
- Zhidan Zeng
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Ningbo 315211, China; (Z.Z.); (Y.G.); (Z.W.); (Z.C.); (D.P.)
- Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China
| | - Xiaoqun Zeng
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Ningbo 315211, China; (Z.Z.); (Y.G.); (Z.W.); (Z.C.); (D.P.)
- Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China
- Correspondence:
| | - Yuxing Guo
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Ningbo 315211, China; (Z.Z.); (Y.G.); (Z.W.); (Z.C.); (D.P.)
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210097, China
| | - Zhen Wu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Ningbo 315211, China; (Z.Z.); (Y.G.); (Z.W.); (Z.C.); (D.P.)
- Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China
| | - Zhendong Cai
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Ningbo 315211, China; (Z.Z.); (Y.G.); (Z.W.); (Z.C.); (D.P.)
- Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China
| | - Daodong Pan
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Ningbo 315211, China; (Z.Z.); (Y.G.); (Z.W.); (Z.C.); (D.P.)
- Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China
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5
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Cloning, Expression and Characterization of UDP-Glucose Dehydrogenases. Life (Basel) 2021; 11:life11111201. [PMID: 34833077 PMCID: PMC8617651 DOI: 10.3390/life11111201] [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: 10/12/2021] [Revised: 11/03/2021] [Accepted: 11/04/2021] [Indexed: 01/17/2023] Open
Abstract
Uridine diphosphate-glucose dehydrogenase (UGD) is an enzyme that produces uridine diphosphate-glucuronic acid (UDP-GlcA), which is an intermediate in glycosaminoglycans (GAGs) production pathways. GAGs are generally extracted from animal tissues. Efforts to produce GAGs in a safer way have been conducted by constructing artificial biosynthetic pathways in heterologous microbial hosts. This work characterizes novel enzymes with potential for UDP-GlcA biotechnological production. The UGD enzymes from Zymomonas mobilis (ZmUGD) and from Lactobacillus johnsonii (LbjUGD) were expressed in Escherichia coli. These two enzymes and an additional eukaryotic one from Capra hircus (ChUGD) were also expressed in Saccharomyces cerevisiae strains. The three enzymes herein studied represent different UGD phylogenetic groups. The UGD activity was evaluated through UDP-GlcA quantification in vivo and after in vitro reactions. Engineered E. coli strains expressing ZmUGD and LbjUGD were able to produce in vivo 28.4 µM and 14.9 µM UDP-GlcA, respectively. Using S. cerevisiae as the expression host, the highest in vivo UDP-GlcA production was obtained for the strain CEN.PK2-1C expressing ZmUGD (17.9 µM) or ChUGD (14.6 µM). Regarding the in vitro assays, under the optimal conditions, E. coli cell extract containing LbjUGD was able to produce about 1800 µM, while ZmUGD produced 407 µM UDP-GlcA, after 1 h of reaction. Using engineered yeasts, the in vitro production of UDP-GlcA reached a maximum of 533 µM using S. cerevisiae CEN.PK2-1C_pSP-GM_LbjUGD cell extract. The UGD enzymes were active in both prokaryotic and eukaryotic hosts, therefore the genes and expression chassis herein used can be valuable alternatives for further industrial applications.
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6
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Cairo J, Gherman I, Day A, Cook PE. Bacillus cytotoxicus-A potentially virulent food-associated microbe. J Appl Microbiol 2021; 132:31-40. [PMID: 34260791 PMCID: PMC9291862 DOI: 10.1111/jam.15214] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 06/15/2021] [Accepted: 07/02/2021] [Indexed: 11/29/2022]
Abstract
Bacillus cytotoxicus is a member of the Bacillus cereus group with the ability to grow at high temperatures (up to 52℃) and to synthesize cytotoxin K-1, a diarrhoeagenic cytotoxin, which appears to be unique to this species and more cytotoxic than the cytotoxin K-2 produced by other members of this group. Only a few isolates of this species have been characterized with regard to their cytotoxic effects, and the role of cytotoxin K-1 as a causative agent of food poisoning remains largely unclear. Bacillus cytotoxicus was initially isolated from a food-borne outbreak, which led to three deaths, and the organism has since been linked to other outbreaks all involving plant-based food matrices. Other studies, as well as food-borne incidents reported to the UK Food Standards Agency, detected B. cytotoxicus in insect-related products and in dried food products. With insect-related food becoming increasingly popular, the association with this pathogen is concerning, requiring further investigation and evidence to protect public health. This review summarizes the current knowledge around B. cytotoxicus and highlights gaps in the literature from a food safety perspective.
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7
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Borg AJE, Beerens K, Pfeiffer M, Desmet T, Nidetzky B. Stereo-electronic control of reaction selectivity in short-chain dehydrogenases: Decarboxylation, epimerization, and dehydration. Curr Opin Chem Biol 2020; 61:43-52. [PMID: 33166830 DOI: 10.1016/j.cbpa.2020.09.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 09/18/2020] [Accepted: 09/27/2020] [Indexed: 12/20/2022]
Abstract
Sugar nucleotide-modifying enzymes of the short-chain dehydrogenase/reductase type use transient oxidation-reduction by a tightly bound nicotinamide cofactor as a common strategy of catalysis to promote a diverse set of reactions, including decarboxylation, single- or double-site epimerization, and dehydration. Although the basic mechanistic principles have been worked out decades ago, the finely tuned control of reactivity and selectivity in several of these enzymes remains enigmatic. Recent evidence on uridine 5'-diphosphate (UDP)-glucuronic acid decarboxylases (UDP-xylose synthase, UDP-apiose/UDP-xylose synthase) and UDP-glucuronic acid-4-epimerase suggests that stereo-electronic constraints established at the enzyme's active site control the selectivity, and the timing of the catalytic reaction steps, in the conversion of the common substrate toward different products. The mechanistic idea of stereo-electronic control is extended to epimerases and dehydratases that deprotonate the Cα of the transient keto-hexose intermediate. The human guanosine 5'-diphosphate (GDP)-mannose 4,6-dehydratase was recently shown to use a minimal catalytic machinery, exactly as predicted earlier from theoretical considerations, for the β-elimination of water from the keto-hexose species.
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Affiliation(s)
- Annika J E Borg
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, 8010, Graz, Austria
| | - Koen Beerens
- Centre for Synthetic Biology, Department of Biotechnology, Ghent University, 9000, Ghent, Belgium
| | - Martin Pfeiffer
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, 8010, Graz, Austria; Austrian Centre of Industrial Biotechnology (acib), 8010, Graz, Austria
| | - Tom Desmet
- Centre for Synthetic Biology, Department of Biotechnology, Ghent University, 9000, Ghent, Belgium; Austrian Centre of Industrial Biotechnology (acib), 8010, Graz, Austria
| | - Bernd Nidetzky
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, 8010, Graz, Austria; Austrian Centre of Industrial Biotechnology (acib), 8010, Graz, Austria.
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8
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Borg AJE, Dennig A, Weber H, Nidetzky B. Mechanistic characterization of UDP-glucuronic acid 4-epimerase. FEBS J 2020; 288:1163-1178. [PMID: 32645249 PMCID: PMC7984243 DOI: 10.1111/febs.15478] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 06/22/2020] [Accepted: 07/06/2020] [Indexed: 12/27/2022]
Abstract
UDP-glucuronic acid (UDP-GlcA) is a central precursor in sugar nucleotide biosynthesis and common substrate for C4-epimerases and decarboxylases releasing UDP-galacturonic acid (UDP-GalA) and UDP-pentose products, respectively. Despite the different reactions catalyzed, the enzymes are believed to share mechanistic analogy rooted in their joint membership to the short-chain dehydrogenase/reductase (SDR) protein superfamily: Oxidation at the substrate C4 by enzyme-bound NAD+ initiates the catalytic pathway. Here, we present mechanistic characterization of the C4-epimerization of UDP-GlcA, which in comparison with the corresponding decarboxylation has been largely unexplored. The UDP-GlcA 4-epimerase from Bacillus cereus functions as a homodimer and contains one NAD+ /subunit (kcat = 0.25 ± 0.01 s-1 ). The epimerization of UDP-GlcA proceeds via hydride transfer from and to the substrate's C4 while retaining the enzyme-bound cofactor in its oxidized form (≥ 97%) at steady state and without trace of decarboxylation. The kcat for UDP-GlcA conversion shows a kinetic isotope effect of 2.0 (±0.1) derived from substrate deuteration at C4. The proposed enzymatic mechanism involves a transient UDP-4-keto-hexose-uronic acid intermediate whose formation is rate-limiting overall, and is governed by a conformational step before hydride abstraction from UDP-GlcA. Precise positioning of the substrate in a kinetically slow binding step may be important for the epimerase to establish stereo-electronic constraints in which decarboxylation of the labile β-keto acid species is prevented effectively. Mutagenesis and pH studies implicate the conserved Tyr149 as the catalytic base for substrate oxidation and show its involvement in the substrate positioning step. Collectively, this study suggests that based on overall mechanistic analogy, stereo-electronic control may be a distinguishing feature of catalysis by SDR-type epimerases and decarboxylases active on UDP-GlcA.
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Affiliation(s)
- Annika J E Borg
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Austria
| | - Alexander Dennig
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Austria.,Austrian Centre of Industrial Biotechnology, Graz, Austria
| | - Hansjörg Weber
- Institute of Organic Chemistry, Graz University of Technology, NAWI Graz, Austria
| | - Bernd Nidetzky
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Austria.,Austrian Centre of Industrial Biotechnology, Graz, Austria
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9
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Iacovino LG, Savino S, Borg AJE, Binda C, Nidetzky B, Mattevi A. Crystallographic snapshots of UDP-glucuronic acid 4-epimerase ligand binding, rotation, and reduction. J Biol Chem 2020; 295:12461-12473. [PMID: 32661196 DOI: 10.1074/jbc.ra120.014692] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 07/10/2020] [Indexed: 11/06/2022] Open
Abstract
UDP-glucuronic acid is converted to UDP-galacturonic acid en route to a variety of sugar-containing metabolites. This reaction is performed by a NAD+-dependent epimerase belonging to the short-chain dehydrogenase/reductase family. We present several high-resolution crystal structures of the UDP-glucuronic acid epimerase from Bacillus cereus The geometry of the substrate-NAD+ interactions is finely arranged to promote hydride transfer. The exquisite complementarity between glucuronic acid and its binding site is highlighted by the observation that the unligated cavity is occupied by a cluster of ordered waters whose positions overlap the polar groups of the sugar substrate. Co-crystallization experiments led to a structure where substrate- and product-bound enzymes coexist within the same crystal. This equilibrium structure reveals the basis for a "swing and flip" rotation of the pro-chiral 4-keto-hexose-uronic acid intermediate that results from glucuronic acid oxidation, placing the C4' atom in position for receiving a hydride ion on the opposite side of the sugar ring. The product-bound active site is almost identical to that of the substrate-bound structure and satisfies all hydrogen-bonding requirements of the ligand. The structure of the apoenzyme together with the kinetic isotope effect and mutagenesis experiments further outlines a few flexible loops that exist in discrete conformations, imparting structural malleability required for ligand rotation while avoiding leakage of the catalytic intermediate and/or side reactions. These data highlight the double nature of the enzymatic mechanism: the active site features a high degree of precision in substrate recognition combined with the flexibility required for intermediate rotation.
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Affiliation(s)
- Luca Giacinto Iacovino
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Pavia, Italy
| | - Simone Savino
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Graz, Austria
| | - Annika J E Borg
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Graz, Austria
| | - Claudia Binda
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Pavia, Italy
| | - Bernd Nidetzky
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Graz, Austria .,Austrian Centre of Industrial Biotechnology, Graz, Austria
| | - Andrea Mattevi
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Pavia, Italy
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Smith JA, Bar-Peled M. Identification of an apiosyltransferase in the plant pathogen Xanthomonas pisi. PLoS One 2018; 13:e0206187. [PMID: 30335828 PMCID: PMC6193724 DOI: 10.1371/journal.pone.0206187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 10/07/2018] [Indexed: 01/14/2023] Open
Abstract
The rare branched-chain sugar apiose, once thought to only be present in the plant kingdom, was found in two bacterial species: Geminicoccus roseus and Xanthomonas pisi. Glycans with apiose residues were detected in aqueous methanol-soluble fractions as well as in the insoluble pellet fraction of X. pisi. Genes encoding bacterial uridine diphosphate apiose (UDP-apiose) synthases (bUASs) were characterized in these bacterial species, but the enzyme(s) involved in the incorporation of the apiose into glycans remained unknown. In the X. pisi genome two genes flanking the XpUAS were annotated as hypothetical glycosyltransferase (GT) proteins. The first GT (here on named XpApiT) belongs to GT family 90 and has a Leloir type B fold and a putative lipopolysaccharide-modifying (LPS) domain. The second GT (here on XpXylT) belongs to GT family 2 and has a type A fold. The XpXylT and XpApiT genes were cloned and heterologously expressed in E. coli. Analysis of nucleotide sugar extracts from E. coli expressing XpXylT or XpApiT with UAS showed that recombinant XpApiT utilized UDP-apiose and XpXylT utilized UDP-xylose as substrate. Indirect activity assay (UDP-Glo) revealed that XpApiT is an apiosyltransferase (ApiT) able to specifically use UDP-apiose. Further support for the apiosyltransferase activity was demonstrated by in microbe co-expression of UAS and XpApiT in E. coli showing the utilization of UDP-apiose to generate an apioside detectable in the pellet fraction. This work provides evidence that X. pisi developed the ability to synthesize an apioside of indeterminate function; however, the evolution of the bacterial ApiT remains to be determined. From genetic and evolutionary perspectives, the apiose operon may provide a unique opportunity to examine how genomic changes reflect ecological adaptation during the divergence of a bacterial group.
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Affiliation(s)
- James Amor Smith
- Complex Carbohydrate Research Center (CCRC), University of Georgia, Athens, GA, United States of America
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States of America
| | - Maor Bar-Peled
- Complex Carbohydrate Research Center (CCRC), University of Georgia, Athens, GA, United States of America
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States of America
- Department of Plant Biology, University of Georgia, Athens, GA, United States of America
- * E-mail:
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11
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The Catabolite Repressor/Activator Cra Is a Bridge Connecting Carbon Metabolism and Host Colonization in the Plant Drought Resistance-Promoting Bacterium Pantoea alhagi LTYR-11Z. Appl Environ Microbiol 2018; 84:AEM.00054-18. [PMID: 29703735 DOI: 10.1128/aem.00054-18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 04/20/2018] [Indexed: 12/22/2022] Open
Abstract
Efficient root colonization is a prerequisite for application of plant growth-promoting (PGP) bacteria in improving health and yield of agricultural crops. We have recently identified an endophytic bacterium, Pantoea alhagi LTYR-11Z, with multiple PGP properties that effectively colonizes the root system of wheat and improves its growth and drought tolerance. To identify novel regulatory genes required for wheat colonization, we screened an LTYR-11Z transposon (Tn) insertion library and found cra to be a colonization-related gene. By using transcriptome (RNA-seq) analysis, we found that transcriptional levels of an eps operon, the ydiV gene encoding an anti-FlhD4C2 factor, and the yedQ gene encoding an enzyme for synthesis of cyclic dimeric GMP (c-di-GMP) were significantly downregulated in the Δcra mutant. Further studies demonstrated that Cra directly binds to the promoters of the eps operon, ydiV, and yedQ and activates their expression, thus inhibiting motility and promoting exopolysaccharide (EPS) production and biofilm formation. Consistent with previous findings that Cra plays a role in transcriptional regulation in response to carbon source availability, the activating effects of Cra were much more pronounced when LTYR-11Z was grown within a gluconeogenic environment than when it was grown within a glycolytic environment. We further demonstrate that the ability of LTYR-11Z to colonize wheat roots is modulated by the availability of carbon sources. Altogether, these results uncover a novel strategy utilized by LTYR-11Z to achieve host colonization in response to carbon nutrition in the environment, in which Cra bridges a connection between carbon metabolism and colonization capacity of LTYR-11Z.IMPORTANCE Rapid and appropriate response to environmental signals is crucial for bacteria to adapt to competitive environments and to establish interactions with their hosts. Efficient colonization and persistence within the host are controlled by various regulatory factors that respond to specific environmental cues. The most common is nutrient availability. In this work, we unraveled the pivotal role of Cra in regulation of colonization ability of Pantoea alhagi LTYR-11Z in response to carbon source availability. Moreover, we identified three novel members of the Cra regulon involved in EPS synthesis, regulation of flagellar biosynthesis, and synthesis of c-di-GMP and propose a working model to explain the Cra-mediated regulatory mechanism that links carbon metabolism to host colonization. This study elucidates the regulatory role of Cra in bacterial attachment and colonization of plants, which raises the possibility of extending our studies to other bacteria associated with plant and human health.
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Ding X, Li J, Pan Y, Zhang Y, Ni L, Wang Y, Zhang X. Genome-Wide Identification and Expression Analysis of the UGlcAE Gene Family in Tomato. Int J Mol Sci 2018; 19:ijms19061583. [PMID: 29861481 PMCID: PMC6032376 DOI: 10.3390/ijms19061583] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 05/20/2018] [Accepted: 05/23/2018] [Indexed: 12/19/2022] Open
Abstract
The UGlcAE has the capability of interconverting UDP-d-galacturonic acid and UDP-d-glucuronic acid, and UDP-d-galacturonic acid is an activated precursor for the synthesis of pectins in plants. In this study, we identified nine UGlcAE protein-encoding genes in tomato. The nine UGlcAE genes that were distributed on eight chromosomes in tomato, and the corresponding proteins contained one or two trans-membrane domains. The phylogenetic analysis showed that SlUGlcAE genes could be divided into seven groups, designated UGlcAE1 to UGlcAE6, of which the UGlcAE2 were classified into two groups. Expression profile analysis revealed that the SlUGlcAE genes display diverse expression patterns in various tomato tissues. Selective pressure analysis indicated that all of the amino acid sites of SlUGlcAE proteins are undergoing purifying selection. Fifteen stress-, hormone-, and development-related elements were identified in the upstream regions (0.5 kb) of these SlUGlcAE genes. Furthermore, we investigated the expression patterns of SlUGlcAE genes in response to three hormones (indole-3-acetic acid (IAA), gibberellin (GA), and salicylic acid (SA)). We detected firmness, pectin contents, and expression levels of UGlcAE family genes during the development of tomato fruit. Here, we systematically summarize the general characteristics of the SlUGlcAE genes in tomato, which could provide a basis for further function studies of tomato UGlcAE genes.
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Affiliation(s)
- Xing Ding
- Key Laboratory of Horticulture Science for Southern Mountainous Regions (Chinese Ministry of Education), College of Horticulture and Landscape Architecture, Southwest University, Chongqing 400715, China.
| | - Jinhua Li
- Key Laboratory of Horticulture Science for Southern Mountainous Regions (Chinese Ministry of Education), College of Horticulture and Landscape Architecture, Southwest University, Chongqing 400715, China.
| | - Yu Pan
- Key Laboratory of Horticulture Science for Southern Mountainous Regions (Chinese Ministry of Education), College of Horticulture and Landscape Architecture, Southwest University, Chongqing 400715, China.
| | - Yue Zhang
- Key Laboratory of Horticulture Science for Southern Mountainous Regions (Chinese Ministry of Education), College of Horticulture and Landscape Architecture, Southwest University, Chongqing 400715, China.
| | - Lei Ni
- Key Laboratory of Horticulture Science for Southern Mountainous Regions (Chinese Ministry of Education), College of Horticulture and Landscape Architecture, Southwest University, Chongqing 400715, China.
| | - Yaling Wang
- Key Laboratory of Horticulture Science for Southern Mountainous Regions (Chinese Ministry of Education), College of Horticulture and Landscape Architecture, Southwest University, Chongqing 400715, China.
| | - Xingguo Zhang
- Key Laboratory of Horticulture Science for Southern Mountainous Regions (Chinese Ministry of Education), College of Horticulture and Landscape Architecture, Southwest University, Chongqing 400715, China.
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Liu J, Zhang J, Wang J, Zhang J, Miao H, Jia C, Wang Z, Xu B, Jin Z. MuMADS1 and MaOFP1 regulate fruit quality in a tomato ovate mutant. PLANT BIOTECHNOLOGY JOURNAL 2018; 16:989-1001. [PMID: 28944538 PMCID: PMC5902769 DOI: 10.1111/pbi.12843] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 09/11/2017] [Accepted: 09/20/2017] [Indexed: 05/11/2023]
Abstract
Fruit ripening and quality are common botanical phenomena that are closely linked and strictly regulated by transcription factors. It was previously discovered that a banana MADS-box protein named MuMADS1 interacted with an ovate family protein named MaOFP1 to regulate banana fruit ripening. To further investigate the role of MuMADS1 and MaOFP1 in the regulation of fruit quality, a combination of genetic transformation and transcriptional characterization was used. The results indicated that the co-expression of MuMADS1 and MaOFP1 in the ovate mutant could compensate for fruit shape and inferior qualities relating to fruit firmness, soluble solids and sugar content. The number of differentially expressed genes (DEGs) was 1395 in WT vs. ovate, with 883 up-regulated and 512 down-regulated genes, while the numbers of DEGs gradually decreased with the transformation of MuMADS1 and MaOFP1 into ovate. 'Starch and sucrose metabolism' constituted the primary metabolic pathway, and the gene numbers in this pathway were obviously different when MuMADS1 and MaOFP1 were integrated into ovate. A series of metabolic genes involved in cell wall biosynthesis were up-regulated in the WT vs. ovate, which probably resulted in the firmer texture and lower sugar contents in the ovate fruit. These results demonstrate that MuMADS1 and MaOFP1 are coregulators of fruit quality, facilitating the dissection of the molecular mechanisms underlying fruit quality formation.
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Affiliation(s)
- Juhua Liu
- Key Laboratory of Tropical Crop BiotechnologyMinistry of AgricultureInstitute of Tropical Bioscience and BiotechnologyChinese Academy of Tropical Agricultural SciencesHaikouChina
| | - Jing Zhang
- Key Laboratory of Tropical Crop BiotechnologyMinistry of AgricultureInstitute of Tropical Bioscience and BiotechnologyChinese Academy of Tropical Agricultural SciencesHaikouChina
| | - Jingyi Wang
- Key Laboratory of Tropical Crop BiotechnologyMinistry of AgricultureInstitute of Tropical Bioscience and BiotechnologyChinese Academy of Tropical Agricultural SciencesHaikouChina
| | - Jianbin Zhang
- Key Laboratory of Tropical Crop BiotechnologyMinistry of AgricultureInstitute of Tropical Bioscience and BiotechnologyChinese Academy of Tropical Agricultural SciencesHaikouChina
| | - Hongxia Miao
- Key Laboratory of Tropical Crop BiotechnologyMinistry of AgricultureInstitute of Tropical Bioscience and BiotechnologyChinese Academy of Tropical Agricultural SciencesHaikouChina
| | - Caihong Jia
- Key Laboratory of Tropical Crop BiotechnologyMinistry of AgricultureInstitute of Tropical Bioscience and BiotechnologyChinese Academy of Tropical Agricultural SciencesHaikouChina
| | - Zhuo Wang
- Key Laboratory of Tropical Crop BiotechnologyMinistry of AgricultureInstitute of Tropical Bioscience and BiotechnologyChinese Academy of Tropical Agricultural SciencesHaikouChina
| | - Biyu Xu
- Key Laboratory of Tropical Crop BiotechnologyMinistry of AgricultureInstitute of Tropical Bioscience and BiotechnologyChinese Academy of Tropical Agricultural SciencesHaikouChina
| | - Zhiqiang Jin
- Key Laboratory of Tropical Crop BiotechnologyMinistry of AgricultureInstitute of Tropical Bioscience and BiotechnologyChinese Academy of Tropical Agricultural SciencesHaikouChina
- Key Laboratory of Genetic Improvement of BananasHainan ProvinceHaikou Experimental StationChinese Academy of Tropical Agricultural SciencesHaikouChina
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Meng X, Lv Y, Mujahid H, Edelmann MJ, Zhao H, Peng X, Peng Z. Proteome-wide lysine acetylation identification in developing rice (Oryza sativa) seeds and protein co-modification by acetylation, succinylation, ubiquitination, and phosphorylation. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2017; 1866:451-463. [PMID: 29313810 DOI: 10.1016/j.bbapap.2017.12.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 11/20/2017] [Accepted: 12/03/2017] [Indexed: 12/31/2022]
Abstract
Protein lysine acetylation is a highly conserved post-translational modification with various biological functions. However, only a limited number of acetylation sites have been reported in plants, especially in cereals, and the function of non-histone protein acetylation is still largely unknown. In this report, we identified 1003 lysine acetylation sites in 692 proteins of developing rice seeds, which greatly extended the number of known acetylated sites in plants. Seven distinguished motifs were detected flanking acetylated lysines. Functional annotation analyses indicated diverse biological processes and pathways engaged in lysine acetylation. Remarkably, we found that several key enzymes in storage starch synthesis pathway and the main storage proteins were heavily acetylated. A comprehensive comparison of the rice acetylome, succinylome, ubiquitome and phosphorylome with available published data was conducted. A large number of proteins carrying multiple kinds of modifications were identified and many of these proteins are known to be key enzymes of vital metabolic pathways. Our study provides extending knowledge of protein acetylation. It will have critical reference value for understanding the mechanisms underlying PTM mediated multiple signal integration in the regulation of metabolism and development in plants.
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Affiliation(s)
- Xiaoxi Meng
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Starkville, MS, United States
| | - Yuanda Lv
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Starkville, MS, United States; Provincial Key Laboratory of Agrobiology, Institute of Biotechnology, Jiangsu Academy of Agricultural Sciences, Nanjing, Jiangsu, China
| | - Hana Mujahid
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Starkville, MS, United States
| | - Mariola J Edelmann
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, United States
| | - Han Zhao
- Provincial Key Laboratory of Agrobiology, Institute of Biotechnology, Jiangsu Academy of Agricultural Sciences, Nanjing, Jiangsu, China
| | - Xiaojun Peng
- Department of Bioinformatics, Jingjie PTM Biolab Co. Ltd, Hangzhou, Zhejiang, China
| | - Zhaohua Peng
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Starkville, MS, United States.
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Smith JA, Bar-Peled M. Synthesis of UDP-apiose in Bacteria: The marine phototroph Geminicoccus roseus and the plant pathogen Xanthomonas pisi. PLoS One 2017; 12:e0184953. [PMID: 28931093 PMCID: PMC5607165 DOI: 10.1371/journal.pone.0184953] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 09/05/2017] [Indexed: 11/22/2022] Open
Abstract
The branched-chain sugar apiose was widely assumed to be synthesized only by plant species. In plants, apiose-containing polysaccharides are found in vascularized plant cell walls as the pectic polymers rhamnogalacturonan II and apiogalacturonan. Apiosylated secondary metabolites are also common in many plant species including ancestral avascular bryophytes and green algae. Apiosyl-residues have not been documented in bacteria. In a screen for new bacterial glycan structures, we detected small amounts of apiose in methanolic extracts of the aerobic phototroph Geminicoccus roseus and the pathogenic soil-dwelling bacteria Xanthomonas pisi. Apiose was also present in the cell pellet of X. pisi. Examination of these bacterial genomes uncovered genes with relatively low protein homology to plant UDP-apiose/UDP-xylose synthase (UAS). Phylogenetic analysis revealed that these bacterial UAS-like homologs belong in a clade distinct to UAS and separated from other nucleotide sugar biosynthetic enzymes. Recombinant expression of three bacterial UAS-like proteins demonstrates that they actively convert UDP-glucuronic acid to UDP-apiose and UDP-xylose. Both UDP-apiose and UDP-xylose were detectable in cell cultures of G. roseus and X. pisi. We could not, however, definitively identify the apiosides made by these bacteria, but the detection of apiosides coupled with the in vivo transcription of bUAS and production of UDP-apiose clearly demonstrate that these microbes have evolved the ability to incorporate apiose into glycans during their lifecycles. While this is the first report to describe enzymes for the formation of activated apiose in bacteria, the advantage of synthesizing apiose-containing glycans in bacteria remains unknown. The characteristics of bUAS and its products are discussed.
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Affiliation(s)
- James Amor Smith
- Complex Carbohydrate Research Center (CCRC), University of Georgia, Athens, GA, United States of America
- Dept. of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States of America
| | - Maor Bar-Peled
- Complex Carbohydrate Research Center (CCRC), University of Georgia, Athens, GA, United States of America
- Dept. of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States of America
- Dept. of Plant Biology, University of Georgia, Athens, GA, United States of America
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16
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Harvey DJ. Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2011-2012. MASS SPECTROMETRY REVIEWS 2017; 36:255-422. [PMID: 26270629 DOI: 10.1002/mas.21471] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 01/15/2015] [Indexed: 06/04/2023]
Abstract
This review is the seventh update of the original article published in 1999 on the application of MALDI mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2012. General aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, and fragmentation are covered in the first part of the review and applications to various structural types constitute the remainder. The main groups of compound are oligo- and poly-saccharides, glycoproteins, glycolipids, glycosides, and biopharmaceuticals. Much of this material is presented in tabular form. Also discussed are medical and industrial applications of the technique, studies of enzyme reactions, and applications to chemical synthesis. © 2015 Wiley Periodicals, Inc. Mass Spec Rev 36:255-422, 2017.
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Affiliation(s)
- David J Harvey
- Department of Biochemistry, Oxford Glycobiology Institute, University of Oxford, Oxford, OX1 3QU, UK
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17
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cDNA Isolation and Functional Characterization of UDP-d-glucuronic Acid 4-Epimerase Family from Ornithogalum caudatum. Molecules 2016; 21:molecules21111505. [PMID: 27834878 PMCID: PMC6273887 DOI: 10.3390/molecules21111505] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 11/01/2016] [Accepted: 11/06/2016] [Indexed: 11/16/2022] Open
Abstract
d-Galacturonic acid (GalA) is an important component of GalA-containing polysaccharides in Ornithogalum caudatum. The incorporation of GalA into these polysaccharides from UDP-d-galacturonic acid (UDP-GalA) was reasonably known. However, the cDNAs involved in the biosynthesis of UDP-GalA were still unknown. In the present investigation, one candidate UDP-d-glucuronic acid 4-epimerase (UGlcAE) family with three members was isolated from O. caudatum based on RNA-Seq data. Bioinformatics analyses indicated all of the three isoforms, designated as OcUGlcAE1~3, were members of short-chain dehydrogenases/reductases (SDRs) and shared two conserved motifs. The three full-length cDNAs were then transformed to Pichia pastoris GS115 for heterologous expression. Data revealed both the supernatant and microsomal fractions from the recombinant P. pastoris expressing OcUGlcAE3 can interconvert UDP-GalA and UDP-d-glucuronic acid (UDP-GlcA), while the other two OcUGlcAEs had no activity on UDP-GlcA and UDP-GalA. Furthermore, expression analyses of the three epimerases in varied tissues of O. caudatum were performed by real-time quantitative PCR (RT-qPCR). Results indicated OcUGlcAE3, together with the other two OcUGlcAE-like genes, was root-specific, displaying highest expression in roots. OcUGlcAE3 was UDP-d-glucuronic acid 4-epimerase and thus deemed to be involved in the biosynthesis of root polysaccharides. Moreover, OcUGlcAE3 was proposed to be environmentally induced.
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18
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Safety evaluation of Bacillus cereus isolated from smelly mandarin fish. JOURNAL OF FOOD MEASUREMENT AND CHARACTERIZATION 2016. [DOI: 10.1007/s11694-016-9442-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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19
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Smith J, Yang Y, Levy S, Adelusi OO, Hahn MG, O'Neill MA, Bar-Peled M. Functional Characterization of UDP-apiose Synthases from Bryophytes and Green Algae Provides Insight into the Appearance of Apiose-containing Glycans during Plant Evolution. J Biol Chem 2016; 291:21434-21447. [PMID: 27551039 DOI: 10.1074/jbc.m116.749069] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 08/19/2016] [Indexed: 11/06/2022] Open
Abstract
Apiose is a branched monosaccharide that is present in the cell wall pectic polysaccharides rhamnogalacturonan II and apiogalacturonan and in numerous plant secondary metabolites. These apiose-containing glycans are synthesized using UDP-apiose as the donor. UDP-apiose (UDP-Api) together with UDP-xylose is formed from UDP-glucuronic acid (UDP-GlcA) by UDP-Api synthase (UAS). It was hypothesized that the ability to form Api distinguishes vascular plants from the avascular plants and green algae. UAS from several dicotyledonous plants has been characterized; however, it is not known if avascular plants or green algae produce this enzyme. Here we report the identification and functional characterization of UAS homologs from avascular plants (mosses, liverwort, and hornwort), from streptophyte green algae, and from a monocot (duckweed). The recombinant UAS homologs all form UDP-Api from UDP-glucuronic acid albeit in different amounts. Apiose was detected in aqueous methanolic extracts of these plants. Apiose was detected in duckweed cell walls but not in the walls of the avascular plants and algae. Overexpressing duckweed UAS in the moss Physcomitrella patens led to an increase in the amounts of aqueous methanol-acetonitrile-soluble apiose but did not result in discernible amounts of cell wall-associated apiose. Thus, bryophytes and algae likely lack the glycosyltransferase machinery required to synthesize apiose-containing cell wall glycans. Nevertheless, these plants may have the ability to form apiosylated secondary metabolites. Our data are the first to provide evidence that the ability to form apiose existed prior to the appearance of rhamnogalacturonan II and apiogalacturonan and provide new insights into the evolution of apiose-containing glycans.
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Affiliation(s)
- James Smith
- From the Complex Carbohydrate Research Center and.,Departments of Biochemistry and Molecular Biology and
| | - Yiwen Yang
- Plant Biology, University of Georgia, Athens, Georgia 30602
| | - Shahar Levy
- Departments of Biochemistry and Molecular Biology and
| | | | - Michael G Hahn
- From the Complex Carbohydrate Research Center and.,Plant Biology, University of Georgia, Athens, Georgia 30602
| | | | - Maor Bar-Peled
- From the Complex Carbohydrate Research Center and .,Plant Biology, University of Georgia, Athens, Georgia 30602
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20
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Eixelsberger T, Weber H, Nidetzky B. Probing of the reaction pathway of human UDP-xylose synthase with site-directed mutagenesis. Carbohydr Res 2015; 416:1-6. [PMID: 26342152 DOI: 10.1016/j.carres.2015.08.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Revised: 08/11/2015] [Accepted: 08/12/2015] [Indexed: 11/28/2022]
Abstract
Uridine 5'-diphosphate (UDP)-xylose (UDP-Xyl) synthase (UXS) catalyzes the oxidative decarboxylation of UDP-glucuronic acid (UDP-GlcUA) to UDP-Xyl. The closely related UDP-glucuronic acid 4-epimerase (UGAE) interconverts UDP-GlcUA and UDP-galacturonic acid (UDP-GalUA) in a highly similar manner via the intermediate UDP-xylo-hexopyranos-4-uluronic acid (UDP-4-keto-GlcUA). Unlike UXS, however, UGAE prevents the decarboxylation. Human UXS (hUXS) and UGAE from Arabidopsis thaliana exhibit high structural similarity in the active site, but two catalytically important residues in hUXS (Glu(120) and Arg(277)) are replaced by Ser and Thr in the UGAE group. Additionally, Asn(176), which participates in substrate binding, is changed to Thr. We therefore analyzed single, double and triple mutants of hUXS carrying these substitutions to evaluate their significance for product specificity. All mutants showed considerably lower activities than wild-type hUXS (>1000-fold reduction). NMR spectroscopic analysis of the reaction products showed that UDP-β-L-threo-pentopyranos-4-ulose (UDP-4-keto-Xyl), UDP-Xyl or both, but no UDP-GalUA or UDP-4-keto-GlcUA were formed. Correlation of product characteristics, such as deuterium incorporation, with the amino acid replacements gave insights into structure-function relationships in UXS, suggesting that interaction between active site and overall enzyme structure rather than distinct conserved residues are decisive for product formation.
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Affiliation(s)
- Thomas Eixelsberger
- Institute of Biotechnology and Biochemical Engineering, NAWI Graz, Graz University of Technology, Petersgasse 12/I, A-8010 Graz, Austria
| | - Hansjörg Weber
- Institute of Organic Chemistry, NAWI Graz, Graz University of Technology, Stremayrgasse 9, A-8010 Graz, Austria
| | - Bernd Nidetzky
- Institute of Biotechnology and Biochemical Engineering, NAWI Graz, Graz University of Technology, Petersgasse 12/I, A-8010 Graz, Austria; Austrian Centre of Industrial Biotechnology, Petersgasse 14, A-8010 Graz, Austria.
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21
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Singh S, Michalska K, Bigelow L, Endres M, Kharel MK, Babnigg G, Yennamalli RM, Bingman CA, Joachimiak A, Thorson JS, Phillips GN. Structural Characterization of CalS8, a TDP-α-D-Glucose Dehydrogenase Involved in Calicheamicin Aminodideoxypentose Biosynthesis. J Biol Chem 2015; 290:26249-58. [PMID: 26240141 DOI: 10.1074/jbc.m115.673459] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Indexed: 11/06/2022] Open
Abstract
Classical UDP-glucose 6-dehydrogenases (UGDHs; EC 1.1.1.22) catalyze the conversion of UDP-α-d-glucose (UDP-Glc) to the key metabolic precursor UDP-α-d-glucuronic acid (UDP-GlcA) and display specificity for UDP-Glc. The fundamental biochemical and structural study of the UGDH homolog CalS8 encoded by the calicheamicin biosynthetic gene is reported and represents one of the first studies of a UGDH homolog involved in secondary metabolism. The corresponding biochemical characterization of CalS8 reveals CalS8 as one of the first characterized base-permissive UGDH homologs with a >15-fold preference for TDP-Glc over UDP-Glc. The corresponding structure elucidations of apo-CalS8 and the CalS8·substrate·cofactor ternary complex (at 2.47 and 1.95 Å resolution, respectively) highlight a notably high degree of conservation between CalS8 and classical UGDHs where structural divergence within the intersubunit loop structure likely contributes to the CalS8 base permissivity. As such, this study begins to provide a putative blueprint for base specificity among sugar nucleotide-dependent dehydrogenases and, in conjunction with prior studies on the base specificity of the calicheamicin aminopentosyltransferase CalG4, provides growing support for the calicheamicin aminopentose pathway as a TDP-sugar-dependent process.
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Affiliation(s)
- Shanteri Singh
- From the Center for Pharmaceutical Research and Innovation, University of Kentucky College of Pharmacy, Lexington, Kentucky 40536-0596
| | - Karolina Michalska
- the Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - Lance Bigelow
- the Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - Michael Endres
- the Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - Madan K Kharel
- the School of Pharmacy, University of Maryland Eastern Shore, Princess Anne, Maryland 21853
| | - Gyorgy Babnigg
- the Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - Ragothaman M Yennamalli
- the Department of BioSciences, Department of Chemistry, Rice University, Houston, Texas 77005
| | - Craig A Bingman
- the Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, and
| | - Andrzej Joachimiak
- the Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - Jon S Thorson
- From the Center for Pharmaceutical Research and Innovation, University of Kentucky College of Pharmacy, Lexington, Kentucky 40536-0596,
| | - George N Phillips
- the Department of BioSciences, Department of Chemistry, Rice University, Houston, Texas 77005 the Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, and
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22
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Comparing substrate specificity of two UDP-sugar pyrophosphorylases and efficient one-pot enzymatic synthesis of UDP-GlcA and UDP-GalA. Carbohydr Res 2015; 411:1-5. [PMID: 25942062 DOI: 10.1016/j.carres.2015.04.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2014] [Accepted: 03/03/2015] [Indexed: 01/11/2023]
Abstract
Uridine 5'-diphosphate-glucuronic acid (UDP-GlcA) and UDP-galacturonic acid (UDP-GalA), the unique carboxylic acid-formed sugar nucleotides, are key precursors involved in the biosynthesis of numerous cell components. Limited availability of those components has been hindering the development of efficient ways towards facile synthesis of bioactive glycans such as glycosaminoglycans. In current study, we biochemically characterized two UDP-sugar pyrophosphorylases from Arabidopsis thaliana (AtUSP) and Bifidobacterium infantis ATCC15697 (BiUSP), and compared their activities towards a panel of sugar-1-phosphates and derivatives. Both enzymes showed significant pyrophosphorylation activities towards GlcA-1-phosphate, and AtUSP also exhibited comparable activity towards GalA-1-phosphate. By combining with monosaccharide-1-phosphate kinases, we have developed an efficient and facile one-pot three-enzyme approach to quickly obtain hundreds milligrams of UDP-GlcA and UDP-GalA.
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Li P, Li Z, Beck WD, Callahan PM, Terry AV, Bar-Peled M, Bartlett MG. Bio-generation of stable isotope-labeled internal standards for absolute and relative quantitation of phase II drug metabolites in plasma samples using LC–MS/MS. Anal Bioanal Chem 2015; 407:4053-63. [DOI: 10.1007/s00216-015-8614-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 02/20/2015] [Accepted: 03/03/2015] [Indexed: 01/24/2023]
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Eixelsberger T, Sykora S, Egger S, Brunsteiner M, Kavanagh KL, Oppermann U, Brecker L, Nidetzky B. Structure and mechanism of human UDP-xylose synthase: evidence for a promoting role of sugar ring distortion in a three-step catalytic conversion of UDP-glucuronic acid. J Biol Chem 2012; 287:31349-58. [PMID: 22810237 PMCID: PMC3438964 DOI: 10.1074/jbc.m112.386706] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
UDP-xylose synthase (UXS) catalyzes decarboxylation of UDP-d-glucuronic acid to UDP-xylose. In mammals, UDP-xylose serves to initiate glycosaminoglycan synthesis on the protein core of extracellular matrix proteoglycans. Lack of UXS activity leads to a defective extracellular matrix, resulting in strong interference with cell signaling pathways. We present comprehensive structural and mechanistic characterization of the human form of UXS. The 1.26-Å crystal structure of the enzyme bound with NAD+ and UDP reveals a homodimeric short-chain dehydrogenase/reductase (SDR), belonging to the NDP-sugar epimerases/dehydratases subclass. We show that enzymatic reaction proceeds in three chemical steps via UDP-4-keto-d-glucuronic acid and UDP-4-keto-pentose intermediates. Molecular dynamics simulations reveal that the d-glucuronyl ring accommodated by UXS features a marked 4C1chair to BO,3boat distortion that facilitates catalysis in two different ways. It promotes oxidation at C4 (step 1) by aligning the enzymatic base Tyr147 with the reactive substrate hydroxyl and it brings the carboxylate group at C5 into an almost fully axial position, ideal for decarboxylation of UDP-4-keto-d-glucuronic acid in the second chemical step. The protonated side chain of Tyr147 stabilizes the enolate of decarboxylated C4 keto species (2H1half-chair) that is then protonated from the Si face at C5, involving water coordinated by Glu120. Arg277, which is positioned by a salt-link interaction with Glu120, closes up the catalytic site and prevents release of the UDP-4-keto-pentose and NADH intermediates. Hydrogenation of the C4 keto group by NADH, assisted by Tyr147 as catalytic proton donor, yields UDP-xylose adopting the relaxed 4C1chair conformation (step 3).
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Affiliation(s)
- Thomas Eixelsberger
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, A-8010 Graz, Austria
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