1
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Spiers AJ, Dorfmueller HC, Jerdan R, McGregor J, Nicoll A, Steel K, Cameron S. Bioinformatics characterization of BcsA-like orphan proteins suggest they form a novel family of pseudomonad cyclic-β-glucan synthases. PLoS One 2023; 18:e0286540. [PMID: 37267309 DOI: 10.1371/journal.pone.0286540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 05/18/2023] [Indexed: 06/04/2023] Open
Abstract
Bacteria produce a variety of polysaccharides with functional roles in cell surface coating, surface and host interactions, and biofilms. We have identified an 'Orphan' bacterial cellulose synthase catalytic subunit (BcsA)-like protein found in four model pseudomonads, P. aeruginosa PA01, P. fluorescens SBW25, P. putida KT2440 and P. syringae pv. tomato DC3000. Pairwise alignments indicated that the Orphan and BcsA proteins shared less than 41% sequence identity suggesting they may not have the same structural folds or function. We identified 112 Orphans among soil and plant-associated pseudomonads as well as in phytopathogenic and human opportunistic pathogenic strains. The wide distribution of these highly conserved proteins suggest they form a novel family of synthases producing a different polysaccharide. In silico analysis, including sequence comparisons, secondary structure and topology predictions, and protein structural modelling, revealed a two-domain transmembrane ovoid-like structure for the Orphan protein with a periplasmic glycosyl hydrolase family GH17 domain linked via a transmembrane region to a cytoplasmic glycosyltransferase family GT2 domain. We suggest the GT2 domain synthesises β-(1,3)-glucan that is transferred to the GH17 domain where it is cleaved and cyclised to produce cyclic-β-(1,3)-glucan (CβG). Our structural models are consistent with enzymatic characterisation and recent molecular simulations of the PaPA01 and PpKT2440 GH17 domains. It also provides a functional explanation linking PaPAK and PaPA14 Orphan (also known as NdvB) transposon mutants with CβG production and biofilm-associated antibiotic resistance. Importantly, cyclic glucans are also involved in osmoregulation, plant infection and induced systemic suppression, and our findings suggest this novel family of CβG synthases may provide similar range of adaptive responses for pseudomonads.
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Affiliation(s)
- Andrew J Spiers
- School of Applied Sciences, Abertay University, Dundee, United Kingdom
| | - Helge C Dorfmueller
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Robyn Jerdan
- School of Applied Sciences, Abertay University, Dundee, United Kingdom
| | - Jessica McGregor
- Nuffield Research Placement Students, School of Applied Sciences, Abertay University, Dundee, United Kingdom
| | - Abbie Nicoll
- Nuffield Research Placement Students, School of Applied Sciences, Abertay University, Dundee, United Kingdom
| | - Kenzie Steel
- Nuffield Research Placement Students, School of Applied Sciences, Abertay University, Dundee, United Kingdom
| | - Scott Cameron
- School of Applied Sciences, Abertay University, Dundee, United Kingdom
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2
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Nakajima M. β-1,2-Glucans and associated enzymes. Biologia (Bratisl) 2022. [DOI: 10.1007/s11756-022-01205-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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3
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Kobayashi K, Shimizu H, Tanaka N, Kuramochi K, Nakai H, Nakajima M, Taguchi H. Characterization and structural analyses of a novel glycosyltransferase acting on the β-1,2-glucosidic linkages. J Biol Chem 2022; 298:101606. [PMID: 35065074 PMCID: PMC8861115 DOI: 10.1016/j.jbc.2022.101606] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 01/12/2022] [Accepted: 01/13/2022] [Indexed: 10/26/2022] Open
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4
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Alegun O, Pandeya A, Cui J, Ojo I, Wei Y. Donnan Potential across the Outer Membrane of Gram-Negative Bacteria and Its Effect on the Permeability of Antibiotics. Antibiotics (Basel) 2021; 10:antibiotics10060701. [PMID: 34208097 PMCID: PMC8230823 DOI: 10.3390/antibiotics10060701] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 06/01/2021] [Accepted: 06/07/2021] [Indexed: 11/16/2022] Open
Abstract
The cell envelope structure of Gram-negative bacteria is unique, composed of two lipid bilayer membranes and an aqueous periplasmic space sandwiched in between. The outer membrane constitutes an extra barrier to limit the exchange of molecules between the cells and the exterior environment. Donnan potential is a membrane potential across the outer membrane, resulted from the selective permeability of the membrane, which plays a pivotal role in the permeability of many antibiotics. In this review, we discussed factors that affect the intensity of the Donnan potential, including the osmotic strength and pH of the external media, the osmoregulated periplasmic glucans trapped in the periplasmic space, and the displacement of cell surface charges. The focus of our discussion is the impact of Donnan potential on the cellular permeability of selected antibiotics including fluoroquinolones, tetracyclines, β-lactams, and trimethoprim.
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Affiliation(s)
| | | | | | | | - Yinan Wei
- Correspondence: ; Tel.: +1-8592577085
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5
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Kobayashi K, Nakajima M, Aramasa H, Kimura S, Iwata T, Nakai H, Taguchi H. Large-scale preparation of β-1,2-glucan using quite a small amount of sophorose. Biosci Biotechnol Biochem 2019; 83:1867-1874. [PMID: 31189457 DOI: 10.1080/09168451.2019.1630257] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
A large amount of β-1,2-glucan was produced enzymatically from quite a small amount of sophorose as an acceptor material through three synthesis steps using a sucrose phosphorylase and a 1,2-β-oligoglucan phosphorylase. The first synthesis step was performed in a 200 μL of a reaction solution containing 5 mM sophorose and 1.0 M sucrose. β-1,2-Glucan in a part of the resultant solution was hydrolyzed to β-1,2-glucooligosaccharides by a β-1,2-glucanase. The second synthesis was performed in 25 times the volume for the first synthesis. The hydrolysate solution (1% volume of the reaction solution) was used as an acceptor. After treatment with the β-1,2-glucanase again, the third synthesis was performed 200 times the volume for the second synthesis (1 L). The reaction yield of β-1,2-glucan at each synthesis was 93%, 76% and 91%. Finally, more than 140 g of β-1,2-glucan was synthesized using approximately 20 μg of sophorose as the starting acceptor material. Abbreviations: DPs: degrees of polymerization; SOGP: 1,2-β-oligoglucan phosphorylase; Sopns: β-1,2-glucooligosaccharides with DP of n; Glc1P: α-glucose 1-phosphate; SucP: sucrose phosphorylase from Bifidobacterium longum subsp. longum; SGL: β-1,2-glucanase; CaSGL: Chy400_4174 protein; TLC: thin layer chromatography; GOPOD: glucose oxidase/peroxidase; PGM: phosphoglucomutase; G6PDH: glucose 6-phosphate dehydrogenase.
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Affiliation(s)
- Kaito Kobayashi
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science , Chiba , Japan
| | - Masahiro Nakajima
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science , Chiba , Japan
| | - Hiroki Aramasa
- Faculty of Agriculture, Niigata University , Niigata , Japan
| | - Satoshi Kimura
- Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo , Tokyo , Japan.,Department of Plant & Environmental New Resources, College of Life Sciences, Kyung Hee University , Gyeonggi-do , Republic of Korea
| | - Tadahisa Iwata
- Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo , Tokyo , Japan
| | - Hiroyuki Nakai
- Faculty of Agriculture, Niigata University , Niigata , Japan
| | - Hayao Taguchi
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science , Chiba , Japan
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6
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Shimizu H, Nakajima M, Miyanaga A, Takahashi Y, Tanaka N, Kobayashi K, Sugimoto N, Nakai H, Taguchi H. Characterization and Structural Analysis of a Novel exo-Type Enzyme Acting on β-1,2-Glucooligosaccharides from Parabacteroides distasonis. Biochemistry 2018; 57:3849-3860. [PMID: 29763309 DOI: 10.1021/acs.biochem.8b00385] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
β-1,2-Glucan is a polysaccharide produced mainly by some Gram-negative bacteria as a symbiosis and infectious factor. We recently identified endo-β-1,2-glucanase from Chitinophaga pinensis ( CpSGL) as an enzyme comprising a new family. Here, we report the characteristics and crystal structure of a CpSGL homologue from Parabacteroides distasonis, an intestinal bacterium (BDI_3064 protein), which exhibits distinctive properties of known β-1,2-glucan-degrading enzymes. BDI_3064 hydrolyzed linear β-1,2-glucan and β-1,2-glucooligosaccharides with degrees of polymerization (DPs) of ≥4 to produce sophorose specifically but did not hydrolyze cyclic β-1,2-glucan. This result indicates that BDI_3064 is a new exo-type enzyme. BDI_3064 also produced sophorose from β-1,2-glucooligosaccharide analogues that have a modified reducing end, indicating that BDI_3064 acts on its substrates from the nonreducing end. The crystal structure showed that BDI_3064 possesses additional N-terminal domains 1 and 2, unlike CpSGL. Superimposition of BDI_3064 and CpSGL complexed with ligands showed that R93 in domain 1 overlapped subsite -3 in CpSGL. Docking analysis involving a β-1,2-glucooligosaccharide with DP4 showed that R93 completely blocks the nonreducing end of the docked β-1,2-glucooligosaccharide. This indicates that BDI_3064 employs a distinct mechanism of recognition at the nonreducing end of substrates to act as an exo-type enzyme. Thus, we propose 2-β-d-glucooligosaccharide sophorohydrolase (nonreducing end) as a systematic name for BDI_3064.
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Affiliation(s)
- Hisaka Shimizu
- Department of Applied Biological Science, Faculty of Science and Technology , Tokyo University of Science , 2641 Yamazaki , Noda , Chiba 278-8510 , Japan
| | - Masahiro Nakajima
- Department of Applied Biological Science, Faculty of Science and Technology , Tokyo University of Science , 2641 Yamazaki , Noda , Chiba 278-8510 , Japan
| | - Akimasa Miyanaga
- Department of Chemistry , Tokyo Institute of Technology , 2-12-1, O-okayama , Meguro-ku, Tokyo 152-8551 , Japan
| | - Yuta Takahashi
- Faculty of Agriculture , Niigata University , Niigata 950-2181 , Japan
| | - Nobukiyo Tanaka
- Department of Applied Biological Science, Faculty of Science and Technology , Tokyo University of Science , 2641 Yamazaki , Noda , Chiba 278-8510 , Japan
| | - Kaito Kobayashi
- Department of Applied Biological Science, Faculty of Science and Technology , Tokyo University of Science , 2641 Yamazaki , Noda , Chiba 278-8510 , Japan
| | - Naohisa Sugimoto
- Faculty of Agriculture , Niigata University , Niigata 950-2181 , Japan
| | - Hiroyuki Nakai
- Faculty of Agriculture , Niigata University , Niigata 950-2181 , Japan
| | - Hayao Taguchi
- Department of Applied Biological Science, Faculty of Science and Technology , Tokyo University of Science , 2641 Yamazaki , Noda , Chiba 278-8510 , Japan
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7
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Abe K, Sunagawa N, Terada T, Takahashi Y, Arakawa T, Igarashi K, Samejima M, Nakai H, Taguchi H, Nakajima M, Fushinobu S. Structural and thermodynamic insights into β-1,2-glucooligosaccharide capture by a solute-binding protein in Listeria innocua. J Biol Chem 2018; 293:8812-8828. [PMID: 29678880 DOI: 10.1074/jbc.ra117.001536] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 04/18/2018] [Indexed: 12/26/2022] Open
Abstract
β-1,2-Glucans are bacterial carbohydrates that exist in cyclic or linear forms and play an important role in infections and symbioses involving Gram-negative bacteria. Although several β-1,2-glucan-associated enzymes have been characterized, little is known about how β-1,2-glucan and its shorter oligosaccharides (Sop n s) are captured and imported into the bacterial cell. Here, we report the biochemical and structural characteristics of the Sop n -binding protein (SO-BP, Lin1841) associated with the ATP-binding cassette (ABC) transporter from the Gram-positive bacterium Listeria innocua Calorimetric analysis revealed that SO-BP specifically binds to Sop n s with a degree of polymerization of 3 or more, with Kd values in the micromolar range. The crystal structures of SO-BP in an unliganded open form and in closed complexes with tri-, tetra-, and pentaoligosaccharides (Sop3-5) were determined to a maximum resolution of 1.6 Å. The binding site displayed shape complementarity to Sop n , which adopted a zigzag conformation. We noted that water-mediated hydrogen bonds and stacking interactions play a pivotal role in the recognition of Sop3-5 by SO-BP, consistent with its binding thermodynamics. Computational free-energy calculations and a mutational analysis confirmed that interactions with the third glucose moiety of Sop n s are significantly responsible for ligand binding. A reduction in unfavorable changes in binding entropy that were in proportion to the lengths of the Sop n s was explained by conformational entropy changes. Phylogenetic and sequence analyses indicated that SO-BP ABC transporter homologs, glycoside hydrolases, and other related proteins are co-localized in the genomes of several bacteria. This study may improve our understanding of bacterial β-1,2-glucan metabolism and promote the discovery of unidentified β-1,2-glucan-associated proteins.
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Affiliation(s)
- Koichi Abe
- From the Department of Biotechnology.,Agricultural Bioinformatics Research Unit, and
| | - Naoki Sunagawa
- Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | | | - Yuta Takahashi
- the Faculty of Agriculture, Niigata University, Niigata 950-2181, Japan
| | | | - Kiyohiko Igarashi
- Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.,the VTT Technical Research Centre of Finland, Espoo FI-02044 VTT, Finland, and
| | - Masahiro Samejima
- Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Hiroyuki Nakai
- the Faculty of Agriculture, Niigata University, Niigata 950-2181, Japan
| | - Hayao Taguchi
- the Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - Masahiro Nakajima
- the Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
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8
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Javvadi S, Pandey SS, Mishra A, Pradhan BB, Chatterjee S. Bacterial cyclic β-(1,2)-glucans sequester iron to protect against iron-induced toxicity. EMBO Rep 2017; 19:172-186. [PMID: 29222343 DOI: 10.15252/embr.201744650] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 10/28/2017] [Accepted: 11/07/2017] [Indexed: 12/24/2022] Open
Abstract
Cellular iron homeostasis is critical for survival and growth. Bacteria employ a variety of strategies to sequester iron from the environment and to store intracellular iron surplus that can be utilized in iron-restricted conditions while also limiting the potential for the production of iron-induced reactive oxygen species (ROS). Here, we report that membrane-derived oligosaccharide (mdo) glucan, an intrinsic component of Gram-negative bacteria, sequesters the ferrous form of iron. Iron-binding, uptake, and localization experiments indicated that both secreted and periplasmic β-(1,2)-glucans bind iron specifically and promote growth under iron-restricted conditions. Xanthomonas campestris and Escherichia coli mutants blocked in the production of β-(1,2)-glucan accumulate low amounts of intracellular iron under iron-restricted conditions, whereas they exhibit elevated ROS production and sensitivity under iron-replete conditions. Our results reveal a critical role of glucan in intracellular iron homeostasis conserved in Gram-negative bacteria.
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Affiliation(s)
| | - Sheo Shankar Pandey
- Centre for DNA Fingerprinting and Diagnostics, Nampally Hyderabad, India.,Graduate Studies, Manipal University, Manipal, India
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9
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Ishiguro R, Tanaka N, Abe K, Nakajima M, Maeda T, Miyanaga A, Takahashi Y, Sugimoto N, Nakai H, Taguchi H. Function and structure relationships of a β-1,2-glucooligosaccharide-degrading β-glucosidase. FEBS Lett 2017; 591:3926-3936. [PMID: 29131329 DOI: 10.1002/1873-3468.12911] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 11/04/2017] [Accepted: 11/08/2017] [Indexed: 11/08/2022]
Abstract
BT_3567 protein, a putative β-glucosidase from Bacteroides thetaiotaomicron, exhibits higher activity toward Sop3-5 (Sopn , n: degree of polymerization of β-1,2-glucooligosaccharides) than toward Sop2 , unlike a known β-glucosidase from Listeria innocua which predominantly prefers Sop2 . In the complex structure determined by soaking of a D286N mutant crystal with Sop4 , a Sop3 moiety was observed at subsites -1 to +2. The glucose moiety at subsite +2 forms a hydrogen bond with Asn81, which is replaced with Gly in the L. innocua β-glucosidase. The Km values of the N81G mutant for Sop3-5 are much higher than those of the wild-type, suggesting that Asn81 contributes to the binding to substrates longer than Sop3 .
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Affiliation(s)
- Rikuto Ishiguro
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan
| | - Nobukiyo Tanaka
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan
| | - Koichi Abe
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan
| | - Masahiro Nakajima
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan
| | - Takuma Maeda
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan
| | | | | | | | | | - Hayao Taguchi
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan
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10
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Abstract
Among all the systems developed by enterobacteria to face osmotic stress, only osmoregulated periplasmic glucans (OPGs) were found to be modulated during osmotic fluxes. First detected in 1973 by E.P. Kennedy's group in a study of phospholipid turnover in Escherichia coli, OPGs have been shown across alpha, beta, and gamma subdivisions of the proteobacteria. Discovery of OPG-like compounds in the epsilon subdivision strongly suggested that the presence of periplasmic glucans is essential for almost all proteobacteria. This article offers an overview of the different classes of OPGs. Then, the biosynthesis of OPGs and their regulation in E. coli and other species are discussed. Finally, the biological role of OPGs is developed. Beyond structural function, OPGs are involved in pathogenicity, in particular, by playing a role in signal transduction pathways. Recently, OPG synthesis proteins have been suggested to control cell division and growth rate.
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Affiliation(s)
- Sébastien Bontemps-Gallo
- Univ. Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, F 59000 Lille, France
| | - Jean-Pierre Bohin
- Univ. Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, F 59000 Lille, France
| | - Jean-Marie Lacroix
- Univ. Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, F 59000 Lille, France
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11
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Abe K, Nakajima M, Yamashita T, Matsunaga H, Kamisuki S, Nihira T, Takahashi Y, Sugimoto N, Miyanaga A, Nakai H, Arakawa T, Fushinobu S, Taguchi H. Biochemical and structural analyses of a bacterial endo-β-1,2-glucanase reveal a new glycoside hydrolase family. J Biol Chem 2017; 292:7487-7506. [PMID: 28270506 DOI: 10.1074/jbc.m116.762724] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 03/04/2017] [Indexed: 11/06/2022] Open
Abstract
β-1,2-Glucan is an extracellular cyclic or linear polysaccharide from Gram-negative bacteria, with important roles in infection and symbiosis. Despite β-1,2-glucan's importance in bacterial persistence and pathogenesis, only a few reports exist on enzymes acting on both cyclic and linear β-1,2-glucan. To this end, we purified an endo-β-1,2-glucanase to homogeneity from cell extracts of the environmental species Chitinophaga arvensicola, and an endo-β-1,2-glucanase candidate gene (Cpin_6279) was cloned from the related species Chitinophaga pinensis The Cpin_6279 protein specifically hydrolyzed linear β-1,2-glucan with polymerization degrees of ≥5 and a cyclic counterpart, indicating that Cpin_6279 is an endo-β-1,2-glucananase. Stereochemical analysis demonstrated that the Cpin_6279-catalyzed reaction proceeds via an inverting mechanism. Cpin_6279 exhibited no significant sequence similarity with known glycoside hydrolases (GHs), and thus the enzyme defines a novel GH family, GH144. The crystal structures of the ligand-free and complex forms of Cpin_6279 with glucose (Glc) and sophorotriose (Glc-β-1,2-Glc-β-1,2-Glc) determined up to 1.7 Å revealed that it has a large cavity appropriate for polysaccharide degradation and adopts an (α/α)6-fold slightly similar to that of GH family 15 and 8 enzymes. Mutational analysis indicated that some of the highly conserved acidic residues in the active site are important for catalysis, and the Cpin_6279 active-site architecture provided insights into the substrate recognition by the enzyme. The biochemical characterization and crystal structure of this novel GH may enable discovery of other β-1,2-glucanases and represent a critical advance toward elucidating structure-function relationships of GH enzymes.
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Affiliation(s)
- Koichi Abe
- From the Department of Biotechnology, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657.,the Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510
| | - Masahiro Nakajima
- the Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510,
| | | | - Hiroki Matsunaga
- the Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510
| | - Shinji Kamisuki
- the Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510.,the School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Chuoh-ku, Sagamihara 229-8501
| | - Takanori Nihira
- the Faculty of Agriculture, Niigata University, Niigata 950-2181, and
| | - Yuta Takahashi
- the Faculty of Agriculture, Niigata University, Niigata 950-2181, and
| | - Naohisa Sugimoto
- the Faculty of Agriculture, Niigata University, Niigata 950-2181, and
| | - Akimasa Miyanaga
- the Department of Chemistry, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan
| | - Hiroyuki Nakai
- the Faculty of Agriculture, Niigata University, Niigata 950-2181, and
| | - Takatoshi Arakawa
- From the Department of Biotechnology, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657
| | - Shinya Fushinobu
- From the Department of Biotechnology, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657
| | - Hayao Taguchi
- the Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510
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12
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Dobruchowska JM, Jonsson JO, Fridjonsson OH, Aevarsson A, Kristjansson JK, Altenbuchner J, Watzlawick H, Gerwig GJ, Dijkhuizen L, Kamerling JP, Hreggvidsson GO. Modification of linear (β1→3)-linked gluco-oligosaccharides with a novel recombinant β-glucosyltransferase (trans-β-glucosidase) enzyme from Bradyrhizobium diazoefficiens. Glycobiology 2016; 26:1157-1170. [PMID: 27550196 DOI: 10.1093/glycob/cww074] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 07/14/2016] [Accepted: 07/18/2016] [Indexed: 11/13/2022] Open
Abstract
Recently, we have shown that glycoside hydrolases enzymes of family GH17 from proteobacteria (genera Pseudomonas, Azotobacter) catalyze elongation transfer reactions with laminari-oligosaccharides generating (β1→3) linkages preferably and to a lesser extent (β1→6) or (β1→4) linkages. In the present study, the cloning and characterization of the gene encoding the structurally very similar GH17 domain of the NdvB enzyme from Bradyrhizobium diazoefficiens, designated Glt20, as well as its catalytic properties are described. The Glt20 enzyme was strikingly different from the previously investigated bacterial GH17 enzymes, both regarding substrate specificity and product formation. The Azotobacter and Pseudomonas enzymes cleaved the donor laminari-oligosaccharide substrates three or four moieties from the non-reducing end, generating linear oligosaccharides. In contrast, the Glt20 enzyme cleaved donor laminari-oligosaccharide substrates two glucose moieties from the reducing end, releasing laminaribiose and transferring the remainder to laminari-oligosaccharide acceptor substrates creating only (β1→3)(β1→6) branching points. This enables Glt20 to transfer larger oligosaccharide chains than the other type of bacterial enzymes previously described, and helps explain the biologically significant formation of cyclic β-glucans in B. diazoefficiens.
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Affiliation(s)
- Justyna M Dobruchowska
- Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | | | | | | | | | - Josef Altenbuchner
- Institut für Industrielle Genetik, Universität Stuttgart, Allmandring 31, 70569 Stuttgart, Germany
| | - Hildegard Watzlawick
- Institut für Industrielle Genetik, Universität Stuttgart, Allmandring 31, 70569 Stuttgart, Germany
| | - Gerrit J Gerwig
- Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands.,NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Lubbert Dijkhuizen
- Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Johannis P Kamerling
- Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands.,NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Gudmundur O Hreggvidsson
- Matís, Vínlandsleid 12, 113 Reykjavík, Iceland .,Department of Biology, University of Iceland, Sturlugata 7, 101 Reykjavík, Iceland
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Nakajima M, Yoshida R, Miyanaga A, Abe K, Takahashi Y, Sugimoto N, Toyoizumi H, Nakai H, Kitaoka M, Taguchi H. Functional and Structural Analysis of a β-Glucosidase Involved in β-1,2-Glucan Metabolism in Listeria innocua. PLoS One 2016; 11:e0148870. [PMID: 26886583 PMCID: PMC4757417 DOI: 10.1371/journal.pone.0148870] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2015] [Accepted: 01/25/2016] [Indexed: 11/18/2022] Open
Abstract
Despite the presence of β-1,2-glucan in nature, few β-1,2-glucan degrading enzymes have been reported to date. Recently, the Lin1839 protein from Listeria innocua was identified as a 1,2-β-oligoglucan phosphorylase. Since the adjacent lin1840 gene in the gene cluster encodes a putative glycoside hydrolase family 3 β-glucosidase, we hypothesized that Lin1840 is also involved in β-1,2-glucan dissimilation. Here we report the functional and structural analysis of Lin1840. A recombinant Lin1840 protein (Lin1840r) showed the highest hydrolytic activity toward sophorose (Glc-β-1,2-Glc) among β-1,2-glucooligosaccharides, suggesting that Lin1840 is a β-glucosidase involved in sophorose degradation. The enzyme also rapidly hydrolyzed laminaribiose (β-1,3), but not cellobiose (β-1,4) or gentiobiose (β-1,6) among β-linked gluco-disaccharides. We determined the crystal structures of Lin1840r in complexes with sophorose and laminaribiose as productive binding forms. In these structures, Arg572 forms many hydrogen bonds with sophorose and laminaribiose at subsite +1, which seems to be a key factor for substrate selectivity. The opposite side of subsite +1 from Arg572 is connected to a large empty space appearing to be subsite +2 for the binding of sophorotriose (Glc-β-1,2-Glc-β-1,2-Glc) in spite of the higher Km value for sophorotriose than that for sophorose. The conformations of sophorose and laminaribiose are almost the same on the Arg572 side but differ on the subsite +2 side that provides no interaction with a substrate. Therefore, Lin1840r is unable to distinguish between sophorose and laminaribiose as substrates. These results provide the first mechanistic insights into β-1,2-glucooligosaccharide recognition by β-glucosidase.
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Affiliation(s)
- Masahiro Nakajima
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan
- * E-mail:
| | - Ryuta Yoshida
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan
| | - Akimasa Miyanaga
- Department of Chemistry, Tokyo Institute of Technology, Meguro-ku, Tokyo, Japan
| | - Koichi Abe
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan
| | - Yuta Takahashi
- Graduate School of Science & Technology, Niigata University, Nishi-ku, Niigata, Japan
| | - Naohisa Sugimoto
- Graduate School of Science & Technology, Niigata University, Nishi-ku, Niigata, Japan
| | - Hiroyuki Toyoizumi
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan
| | - Hiroyuki Nakai
- Graduate School of Science & Technology, Niigata University, Nishi-ku, Niigata, Japan
| | - Motomitsu Kitaoka
- National Food Research Institute, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan
| | - Hayao Taguchi
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan
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Larsen PE, Collart FR, Dai Y. Predicting Ecological Roles in the Rhizosphere Using Metabolome and Transportome Modeling. PLoS One 2015; 10:e0132837. [PMID: 26332409 PMCID: PMC4557938 DOI: 10.1371/journal.pone.0132837] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 06/18/2015] [Indexed: 12/17/2022] Open
Abstract
The ability to obtain complete genome sequences from bacteria in environmental samples, such as soil samples from the rhizosphere, has highlighted the microbial diversity and complexity of environmental communities. However, new algorithms to analyze genome sequence information in the context of community structure are needed to enhance our understanding of the specific ecological roles of these organisms in soil environments. We present a machine learning approach using sequenced Pseudomonad genomes coupled with outputs of metabolic and transportomic computational models for identifying the most predictive molecular mechanisms indicative of a Pseudomonad's ecological role in the rhizosphere: a biofilm, biocontrol agent, promoter of plant growth, or plant pathogen. Computational predictions of ecological niche were highly accurate overall with models trained on transportomic model output being the most accurate (Leave One Out Validation F-scores between 0.82 and 0.89). The strongest predictive molecular mechanism features for rhizosphere ecological niche overlap with many previously reported analyses of Pseudomonad interactions in the rhizosphere, suggesting that this approach successfully informs a system-scale level understanding of how Pseudomonads sense and interact with their environments. The observation that an organism's transportome is highly predictive of its ecological niche is a novel discovery and may have implications in our understanding microbial ecology. The framework developed here can be generalized to the analysis of any bacteria across a wide range of environments and ecological niches making this approach a powerful tool for providing insights into functional predictions from bacterial genomic data.
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Affiliation(s)
- Peter E. Larsen
- Argonne National Laboratory, Biosciences Division, Argonne, IL, United States of America
- University of Illinois at Chicago, Department of Bioengineering, Chicago, IL, United States of America
| | - Frank R. Collart
- Argonne National Laboratory, Biosciences Division, Argonne, IL, United States of America
| | - Yang Dai
- University of Illinois at Chicago, Department of Bioengineering, Chicago, IL, United States of America
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Evaluation of the Role of the opgGH Operon in Yersinia pseudotuberculosis and Its Deletion during the Emergence of Yersinia pestis. Infect Immun 2015; 83:3638-47. [PMID: 26150539 DOI: 10.1128/iai.00482-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 06/26/2015] [Indexed: 02/02/2023] Open
Abstract
The opgGH operon encodes glucosyltransferases that synthesize osmoregulated periplasmic glucans (OPGs) from UDP-glucose, using acyl carrier protein (ACP) as a cofactor. OPGs are required for motility, biofilm formation, and virulence in various bacteria. OpgH also sequesters FtsZ in order to regulate cell size according to nutrient availability. Yersinia pestis (the agent of flea-borne plague) lost the opgGH operon during its emergence from the enteropathogen Yersinia pseudotuberculosis. When expressed in OPG-negative strains of Escherichia coli and Dickeya dadantii, opgGH from Y. pseudotuberculosis restored OPGs synthesis, motility, and virulence. However, Y. pseudotuberculosis did not produce OPGs (i) under various growth conditions or (ii) when overexpressing its opgGH operon, its galUF operon (governing UDP-glucose), or the opgGH operon or Acp from E. coli. A ΔopgGH Y. pseudotuberculosis strain showed normal motility, biofilm formation, resistance to polymyxin and macrophages, and virulence but was smaller. Consistently, Y. pestis was smaller than Y. pseudotuberculosis when cultured at ≥ 37°C, except when the plague bacillus expressed opgGH. Y. pestis expressing opgGH grew normally in serum and within macrophages and was fully virulent in mice, suggesting that small cell size was not advantageous in the mammalian host. Lastly, Y. pestis expressing opgGH was able to infect Xenopsylla cheopis fleas normally. Our results suggest an evolutionary scenario whereby an ancestral Yersinia strain lost a factor required for OPG biosynthesis but kept opgGH (to regulate cell size). The opgGH operon was presumably then lost because OpgH-dependent cell size control became unnecessary.
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Batool R, Yrjälä K, Shaukat K, Jamil N, Hasnain S. Production of EPS under Cr(VI) challenge in two indigenous bacteria isolated from a tannery effluent. J Basic Microbiol 2015; 55:1064-74. [DOI: 10.1002/jobm.201400885] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 02/13/2015] [Accepted: 03/13/2015] [Indexed: 11/06/2022]
Affiliation(s)
- Rida Batool
- Department of Microbiology and Molecular Genetics; Quaid-e-Azam Campus; University of the Punjab; Lahore Pakistan
- Department of Biosciences; MEM-Group; University of Helsinki; Finland
| | - Kim Yrjälä
- Department of Biosciences; MEM-Group; University of Helsinki; Finland
| | - Kamran Shaukat
- Department of Applied Sciences; University of Huddersfield; United Kingdom
| | - Nazia Jamil
- Department of Microbiology and Molecular Genetics; Quaid-e-Azam Campus; University of the Punjab; Lahore Pakistan
| | - Shahida Hasnain
- Department of Microbiology and Molecular Genetics; Quaid-e-Azam Campus; University of the Punjab; Lahore Pakistan
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17
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Abe K, Nakajima M, Kitaoka M, Toyoizumi H, Takahashi Y, Sugimoto N, Nakai H, Taguchi H. Large-scale Preparation of 1,2-β-Glucan Using 1,2-β-Oligoglucan Phosphorylase. J Appl Glycosci (1999) 2015. [DOI: 10.5458/jag.jag.jag-2014_011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Affiliation(s)
- Koichi Abe
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science
| | - Masahiro Nakajima
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science
| | - Motomitsu Kitaoka
- National Food Research Institute, National Agriculture and Food Research Organization
| | - Hiroyuki Toyoizumi
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science
| | - Yuta Takahashi
- Graduate School of Science & Technology, Niigata University
| | | | - Hiroyuki Nakai
- Graduate School of Science & Technology, Niigata University
| | - Hayao Taguchi
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science
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18
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Hreggvidsson GO, Dobruchowska JM, Fridjonsson OH, Jonsson JO, Gerwig GJ, Aevarsson A, Kristjansson JK, Curti D, Redgwell RJ, Hansen CE, Kamerling JP, Debeche-Boukhit T, Suzuki N, Nawa D, Yamamoto K, Ju T, Xia B, Aryal RP, Wang W, Wang Y, Ding X, Mi R, He M, Cummings RD. Errata. Glycobiology 2011. [DOI: 10.1093/glycob/cwr035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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19
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Hreggvidsson GO, Dobruchowska JM, Fridjonsson OH, Jonsson JO, Gerwig GJ, Aevarsson A, Kristjansson JK, Curti D, Redgwell RR, Hansen CE, Kamerling JP, Debeche-Boukhit T. Exploring novel non-Leloir β-glucosyltransferases from proteobacteria for modifying linear (β1→3)-linked gluco-oligosaccharide chains. Glycobiology 2010; 21:304-28. [DOI: 10.1093/glycob/cwq165] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
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20
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Osmoregulated Periplasmic Glucan Polymerization Requires Constant Protein Synthesis in Escherichia coli. Curr Microbiol 2010; 61:396-400. [DOI: 10.1007/s00284-010-9625-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Accepted: 03/16/2010] [Indexed: 10/19/2022]
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21
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Penaloza-Vazquez A, Sreedharan A, Bender CL. Transcriptional studies of the hrpM/opgH gene in Pseudomonas syringae during biofilm formation and in response to different environmental challenges. Environ Microbiol 2010; 12:1452-67. [PMID: 20132277 DOI: 10.1111/j.1462-2920.2010.02160.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Pseudomonas syringae pv. syringae strain FF5 is a phytopathogen that causes a rapid dieback on ornamental pear trees. In the present study, the transcriptional expression of hrpM/opgH, algD, hrpR and rpoD was evaluated in P. syringae FF5 and FF5.M2 (hrpM/opgH mutant). The temporal expression of these genes was evaluated during biofilm formation, the hypersensitive reaction (HR) on tobacco plants, and when the bacteria were subjected to different environmental stresses. The results indicate that mutations in hrpM negatively impair several traits including biofilm formation, the ability to cause disease in host plants and the HR in non-host plants, and the expression of hrpR, a regulatory gene modulating the latter two traits. Furthermore, FF5.M2 was decreased in swarming motility and unable to respond to different environmental challenges. Interestingly, FF5.M2 showed an exponential increase in the expression of algD, which is the first gene to be transcribed during the biosynthesis of the alginate, a virulence factor in P. syringae. The expression of both hrpM and algD were required for biofilm formation, and hrpM was expressed earlier than algD during biofilm development. These findings indicate that hrpM expression is required for several traits in P. syringae and plays an important role in how this bacterium responds to environmental challenges.
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Affiliation(s)
- Alejandro Penaloza-Vazquez
- 127 Noble Research Center, Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA
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22
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Novel succinylated and large-sized osmoregulated periplasmic glucans of Pseudomonas syringae pv. syringae. Carbohydr Res 2009; 344:996-1000. [DOI: 10.1016/j.carres.2009.03.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2008] [Revised: 03/13/2009] [Accepted: 03/15/2009] [Indexed: 11/23/2022]
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23
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Gimenez-Ibanez S, Hann DR, Ntoukakis V, Petutschnig E, Lipka V, Rathjen JP. AvrPtoB Targets the LysM Receptor Kinase CERK1 to Promote Bacterial Virulence on Plants. Curr Biol 2009; 19:423-9. [DOI: 10.1016/j.cub.2009.01.054] [Citation(s) in RCA: 269] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2008] [Revised: 01/14/2009] [Accepted: 01/19/2009] [Indexed: 12/26/2022]
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24
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First isolation and structural determination of cyclic β-(1→2)-glucans from an alga, Chlorella pyrenoidosa. Carbohydr Res 2008; 343:2623-33. [DOI: 10.1016/j.carres.2008.07.009] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2008] [Revised: 07/11/2008] [Accepted: 07/16/2008] [Indexed: 11/19/2022]
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25
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Lequette Y, Rollet E, Delangle A, Greenberg EP, Bohin JP. Linear osmoregulated periplasmic glucans are encoded by the opgGH locus of Pseudomonas aeruginosa. Microbiology (Reading) 2007; 153:3255-3263. [PMID: 17906125 DOI: 10.1099/mic.0.2007/008953-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Osmoregulated periplasmic glucans (OPGs) are produced by many proteobacteria and are important for bacterial-host interactions. The opgG and opgH genes involved in the synthesis of OPGs are the most widely distributed genes in proteobacterial genomes. Two other non-homologous genes, both named ndvB, are also involved in OPG biosynthesis in several species. The Pseudomonas aeruginosa genome possesses two ORFs, PA5077 and PA5078, that show similarity to opgH and opgG of Pseudomonas syringae, respectively, and one ORF, PA1163, similar to ndvB of Sinorhizobium meliloti. Here, we report that the opgGH locus of P. aeruginosa PA14 is involved in the synthesis of linear polymers with beta-1,2-linked glucosyl residues branched with a few beta-1,6 glucosyl residues. Succinyl residues also substitute this glucose backbone. Transcription of opgGH is repressed by high osmolarity. Low osmolarity promotes the formation of highly structured biofilms, but biofilm development is slower and the area of biomass is reduced under high osmolarity. Biofilm development of an opgGH mutant grown under low osmolarity presents a similar phenotype to the wild-type biofilm grown under high osmolarity. These results suggest that OPGs are important for biofilm formation under conditions of low osmolarity. A previous study suggested that the P. aeruginosa ndvB gene is involved in the resistance of biofilms to antibiotics. We have shown that ndvB is not involved in the biosynthesis of the OPG described here, and opgGH do not appear to be involved in the resistance of P. aeruginosa PA14 biofilms to antibiotics.
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Affiliation(s)
- Yannick Lequette
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Eglantine Rollet
- Unité de Glycobiologie Structurale et Fonctionnelle CNRS UMR 8576, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq Cedex, France
| | - Aurélie Delangle
- Unité de Glycobiologie Structurale et Fonctionnelle CNRS UMR 8576, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq Cedex, France
| | - E Peter Greenberg
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Jean-Pierre Bohin
- Unité de Glycobiologie Structurale et Fonctionnelle CNRS UMR 8576, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq Cedex, France
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Roset MS, Ciocchini AE, Ugalde RA, Iñón de Iannino N. The Brucella abortus cyclic beta-1,2-glucan virulence factor is substituted with O-ester-linked succinyl residues. J Bacteriol 2006; 188:5003-13. [PMID: 16816173 PMCID: PMC1539967 DOI: 10.1128/jb.00086-06] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2006] [Accepted: 04/26/2006] [Indexed: 01/18/2023] Open
Abstract
Brucella periplasmic cyclic beta-1,2-glucan plays an important role during bacterium-host interaction. Nuclear magnetic resonance spectrometry analysis, thin-layer chromatography, and DEAE-Sephadex chromatography were used to characterize Brucella abortus cyclic glucan. In the present study, we report that a fraction of B. abortus cyclic beta-1,2-glucan is substituted with succinyl residues, which confer anionic character on the cyclic beta-1,2-glucan. The oligosaccharide backbone is substituted at C-6 positions with an average of two succinyl residues per glucan molecule. This O-ester-linked succinyl residue is the only substituent of Brucella cyclic glucan. A B. abortus open reading frame (BAB1_1718) homologous to Rhodobacter sphaeroides glucan succinyltransferase (OpgC) was identified as the gene encoding the enzyme responsible for cyclic glucan modification. This gene was named cgm for cyclic glucan modifier and is highly conserved in Brucella melitensis and Brucella suis. Nucleotide sequencing revealed that B. abortus cgm consists of a 1,182-bp open reading frame coding for a predicted membrane protein of 393 amino acid residues (42.7 kDa) 39% identical to Rhodobacter sphaeroides succinyltransferase. cgm null mutants in B. abortus strains 2308 and S19 produced neutral glucans without succinyl residues, confirming the identity of this protein as the cyclic-glucan succinyltransferase enzyme. In this study, we demonstrate that succinyl substituents of cyclic beta-1,2-glucan of B. abortus are necessary for hypo-osmotic adaptation. On the other hand, intracellular multiplication and mouse spleen colonization are not affected in cgm mutants, indicating that cyclic-beta-1,2-glucan succinylation is not required for virulence and suggesting that no low-osmotic stress conditions must be overcome during infection.
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Affiliation(s)
- Mara S Roset
- Instituto de Investigaciones Biotecnológicas, Av. Gral Paz 5445, CP1650, San Martín, Buenos Aires, Argentina
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Zdorovenko EL, Varbanets LD, Zatonsky GV, Ostapchuk AN. Structures of two putative O-specific polysaccharides from the Rahnella aquatilis 3-95 lipopolysaccharide. Carbohydr Res 2006; 341:164-8. [PMID: 16313891 DOI: 10.1016/j.carres.2005.11.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2005] [Revised: 11/09/2005] [Accepted: 11/09/2005] [Indexed: 11/25/2022]
Abstract
Two polysaccharide preparations (OPSI and OPSII) were obtained by mild acid degradation of the lipopolysaccharide of Rahnella aquatilis 3-95. Studies by chemical methods and 1H and 13C NMR spectroscopy showed that OPSI is a linear alpha-D-mannan having a trisaccharide repeat and OPSII is a approximately 2:1 mixture of the same mannan and an alpha-d-glucan:
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Affiliation(s)
- Evelina L Zdorovenko
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospekt 47, 119991 Moscow, Russia.
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Veremeichenko SN, Zdorovenko GM, Zdorovenko EL, Zatonskii GM. Characterization of Lipopolysaccharides from Pseudomonas fluorescens IMB 2108 (Biovar II) and IMB 2111 (Biovar IV) with O-Chains Represented by α-Glucan. Microbiology (Reading) 2005. [DOI: 10.1007/s11021-005-0102-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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29
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Jung Y, Park H, Cho E, Jung S. Structural analyses of novel glycerophosphorylated α-cyclosophorohexadecaoses isolated from X. campestris pv. campestris. Carbohydr Res 2005; 340:673-7. [PMID: 15721339 DOI: 10.1016/j.carres.2004.12.030] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2004] [Accepted: 12/31/2004] [Indexed: 11/24/2022]
Abstract
Novel periplasmic anionic cyclic glucans produced by Xanthomonas campestris pv. campestris were isolated by trichloroacetic acid treatment and various chromatographic techniques. No report has been made on the presence of substituted cyclic glucans of the Xanthomonas species. We show, for the first time, that X. campestris pv. campestris produces the anionic cyclic glucans with phosphoglycerol residues, the presence of which can be predicted by analyzing the sequence database with the aid of the NCBI RefSeq database. To analyze the structure of isolated anionic cyclic glucans analyses, we used NMR spectroscopy, matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOFMS) and electrospray-ionization mass spectrometry (ESIMS). The results suggest that the novel anionic forms of the cyclic glucans of X. campestris pv. campestris are glycerophosphorylated alpha-cyclosophorohexadecaose with one or two phosphoglycerol substituents at the C-6 positions of the glucose residues.
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Affiliation(s)
- Yunjung Jung
- Department of Microbial Engineering and Bio/Molecular Informatics Center, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701, Korea
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Astua-Monge G, Freitas-Astua J, Bacocina G, Roncoletta J, Carvalho SA, Machado MA. Expression profiling of virulence and pathogenicity genes of Xanthomonas axonopodis pv. citri. J Bacteriol 2005; 187:1201-5. [PMID: 15659697 PMCID: PMC545697 DOI: 10.1128/jb.187.3.1201-1205.2005] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
DNA macroarrays of 279 genes of Xanthomonas axonopodis pv. citri potentially associated with pathogenicity and virulence were used to compare the transcriptional alterations of this bacterium in response to two synthetic media. Data analysis indicated that 31 genes were up-regulated by synthetic medium XVM2, while only 7 genes were repressed. The results suggest that XVM2 could be used as an in vitro system to identify candidate genes involved in pathogenesis of X. axonopodis pv. citri.
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Affiliation(s)
- Gustavo Astua-Monge
- Laboratório de Biotecnologia, Centro APTA Citros Sylvio Moreira, Cordeirópolis, São Paulo 13490-970, Brazil.
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Minsavage GV, Mudgett MB, Stall RE, Jones JB. Importance of opgHXcv of Xanthomonas campestris pv. vesicatoria in host-parasite interactions. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2004; 17:152-161. [PMID: 14964529 DOI: 10.1094/mpmi.2004.17.2.152] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Tn5 insertion mutants of Xanthomonas campestris pv. vesicatoria were inoculated into tomato and screened for reduced virulence. One mutant exhibited reduced aggressiveness and attenuated growth in planta. Southern blot analyses indicated that the mutant carried a single Tn5 insertion not associated with previously cloned pathogenicity-related genes of X. campestris pv. vesicatoria. The wild-type phenotype of this mutant was restored by one recombinant plasmid (pOPG361) selected from a genomic library of X. campestris pv. vesicatoria 91-118. Tn3-gus insertion mutagenesis and sequence analyses of a subclone of pOPG361 identified a 1,929-bp open reading frame (ORF) essential for complementation of the mutants. The predicted protein encoded by this ORF was highly homologous to the previously reported pathogenicity-related HrpM protein of Pseudomonas syringae pv. syringae and OpgH of Erwinia chrysanthemi. Based on homology, the new locus was designated opgHXcv. Manipulation of the osmotic potential in the intercellular spaces of tomato leaves by addition of mannitol at low concentrations (25 to 50 mM) compensates for the opgHXcv mutation.
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Affiliation(s)
- G V Minsavage
- Plant Pathology Department, University of Florida, PO Box 110680, Gainesville, FL 32611, USA
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Talaga P, Cogez V, Wieruszeski JM, Stahl B, Lemoine J, Lippens G, Bohin JP. Osmoregulated periplasmic glucans of the free-living photosynthetic bacterium Rhodobacter sphaeroides. EUROPEAN JOURNAL OF BIOCHEMISTRY 2002; 269:2464-72. [PMID: 12027884 DOI: 10.1046/j.1432-1033.2002.02906.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The osmoregulated periplasmic glucans (OPGs) produced by Rhodobacter sphaeroides, a free-living organism, were isolated by trichloracetic acid treatment and gel permeation chromatography. Compounds obtained were characterized by compositional analysis, matrix-assisted laser desorption ionization mass spectrometry and nuclear magnetic resonance. R. sphaeroides predominantly synthesizes a cyclic glucan containing 18 glucose residues that can be substituted by one to seven succinyl esters residues at the C6 position of some of the glucose residues, and by one or two acetyl residues. The glucans were subjected to a mild alkaline treatment in order to remove the succinyl and acetyl substituents, analyzed by MALDI mass spectrometry and purified by high-performance anion-exchange chromatography. Methylation analysis revealed that this glucan is linked by 17 1,2 glycosidic bonds and one 1,6 glycosidic bond. Homonuclear and (1)H/(13)C heteronuclear NMR experiments revealed the presence of a single alpha-1,6 glycosidic linkage, whereas all other glucose residues are beta-1,2 linked. The different anomeric proton signals allowed a complete sequence-specific assignment of the glucan. The structural characteristics of this glucan are very similar to the previously described OPGs of Ralstonia solanacearum and Xanthomonas campestris, except for its different size and the presence of substituents. Therefore, similar OPGs are synthesized by phytopathogenic as well as free-living bacteria, suggesting these compounds are intrinsic components of the Gram-negative bacterial envelope.
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Affiliation(s)
- Philippe Talaga
- Unité de Glycobiologie Structurale et Fonctionnelle, CNRS UMR8576, Université des Sciences et Technologies de Lille, Villeneuve d'Ascq, France
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Abstract
We report the initial characterization of the osmoregulated periplasmic glucans (OPGs) of Erwinia chrysanthemi. OPGs are intrinsic components of the bacterial envelope necessary to the pathogenicity of this phytopathogenic enterobacterium (F. Page, S. Altabe, N. Hugouvieux-Cotte-Pattat, J.-M. Lacroix, J. Robert-Baudouy and J.-P. Bohin, J. Bacteriol. 183:0000-0000, 2001 [companion in this issue]). OPGs were isolated by trichloracetic acid treatment and gel permeation chromatography. The synthesis of these compounds appeared to be osmoregulated, since lower amounts of OPGs were produced when bacteria were grown in media of higher osmolarities. However, a large fraction of these OPGs were recovered in the culture medium. Then, these compounds were characterized by compositional analysis, high-performance anion-exchange chromatography, matrix-assisted laser desorption mass spectrometry, and (1)H and (13)C nuclear magnetic resonance analyses. OPGs produced by E. chrysanthemi are very heterogeneous at the level of both backbone structure and substitution of these structures. The degree of polymerization of the glucose units ranges from 5 to 12. The structures are branched, with a linear backbone consisting of beta-1,2-linked glucose units to which a variable number of branches, composed of one glucose residue, are attached by beta-1,6 linkages in a random way. This glucan backbone may be substituted by O-acetyl and O-succinyl ester-linked residues.
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Affiliation(s)
- V Cogez
- Unité de Glycobiologie Structurale et Fonctionnelle, UMR USTL-CNRS 8576, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq Cedex, France
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Page F, Altabe S, Hugouvieux-Cotte-Pattat N, Lacroix JM, Robert-Baudouy J, Bohin JP. Osmoregulated periplasmic glucan synthesis is required for Erwinia chrysanthemi pathogenicity. J Bacteriol 2001; 183:3134-41. [PMID: 11325942 PMCID: PMC95214 DOI: 10.1128/jb.183.10.3134-3141.2001] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2000] [Accepted: 03/06/2001] [Indexed: 11/20/2022] Open
Abstract
Erwinia chrysanthemi is a phytopathogenic enterobacterium causing soft rot disease in a wide range of plants. Osmoregulated periplasmic glucans (OPGs) are intrinsic components of the gram-negative bacterial envelope. We cloned the opgGH operon of E. chrysanthemi, encoding proteins involved in the glucose backbone synthesis of OPGs, by complementation of the homologous locus mdoGH of Escherichia coli. OpgG and OpgH show a high level of similarity with MdoG and MdoH, respectively, and mutations in the opgG or opgH gene abolish OPG synthesis. The opg mutants exhibit a pleiotropic phenotype, including overproduction of exopolysaccharides, reduced motility, bile salt hypersensitivity, reduced protease, cellulase, and pectate lyase production, and complete loss of virulence. Coinoculation experiments support the conclusion that OPGs present in the periplasmic space of the bacteria are necessary for growth in the plant host.
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Affiliation(s)
- F Page
- Unité de Glycobiologie Structurale et Fonctionnelle, UMR USTL-CNRS 8576, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq Cedex, France
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Abstract
Large amounts of osmoregulated periplasmic glucans (OPGs) are found in the periplasmic space of Proteobacteria. Four families of OPGs are described on the basis of structural features of the polyglucose backbone. Depending on the species considered, OPGs can be modified to various extent by a variety of substituents. Genes governing the backbone synthesis are identified in a limited number of species. They belong to three unrelated families. OPG synthesis is subject to osmoregulation and feedback control. Osmoregulation can occur at the level of gene expression and/or at the level of enzyme activity. Mutants defective in OPG synthesis have a highly pleiotropic phenotype, indicative of an overall alteration of their envelope properties. Mutants of this kind were obtained as attenuated or avirulent derivatives of plant or animals pathogen. Thus, OPGs appear to be important intrinsic components of the Gram-negative bacterial envelope, which can be essential in extreme conditions found in nature, and especially when bacteria must interact with an eukaryotic host.
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Affiliation(s)
- J P Bohin
- Laboratoire de Chimie Biologique, CNRS UMR 8576, Université des Sciences et Technologies de Lille, 59655, Villeneuve d'Ascq, France.
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Lacroix JM, Lanfroy E, Cogez V, Lequette Y, Bohin A, Bohin JP. The mdoC gene of Escherichia coli encodes a membrane protein that is required for succinylation of osmoregulated periplasmic glucans. J Bacteriol 1999; 181:3626-31. [PMID: 10368134 PMCID: PMC93837 DOI: 10.1128/jb.181.12.3626-3631.1999] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Osmoregulated periplasmic glucans (OPGs) of Escherichia coli are anionic oligosaccharides that accumulate in the periplasmic space in response to low osmolarity of the medium. Their anionic character is provided by the substitution of the glucosidic backbone by phosphoglycerol originating from the membrane phospholipids and by succinyl residues from unknown origin. A phosphoglycerol-transferase-deficient mdoB mutant was subjected to Tn5 transposon mutagenesis, and putative mutant clones were screened for changes in the anionic character of OPGs by thin-layer chromatography. One mutant deficient in succinylation of OPGs was obtained, and the gene inactivated in this mutant was characterized and named mdoC. mdoC, which encodes a membrane-bound protein, is closely linked to the mdoGH operon necessary for the synthesis of the OPG backbone.
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Affiliation(s)
- J M Lacroix
- Laboratoire de Chimie Biologique, UMR111 du CNRS, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq, Cedex, France
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Debarbieux L, Bohin A, Bohin JP. Topological analysis of the membrane-bound glucosyltransferase, MdoH, required for osmoregulated periplasmic glucan synthesis in Escherichia coli. J Bacteriol 1997; 179:6692-8. [PMID: 9352918 PMCID: PMC179597 DOI: 10.1128/jb.179.21.6692-6698.1997] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The MdoH protein is essential for synthesis of the osmoregulated periplasmic glucans, known as membrane-derived oligosaccharides (MDOs), in Escherichia coli. Mutants lacking MdoH are deficient in a glucosyltransferase activity assayed in vitro. The MdoH protein is the product of the second gene of an operon, and it has been shown to span the cytoplasmic membrane. The MdoH protein comprises 847 amino acids and is poorly expressed as observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. We have experimentally measured the topological organization of MdoH within the membrane by construction of fusions to beta-lactamase as a reporter. Analysis of 51 different MdoH-beta-lactamase fusions suggested that the MdoH protein crosses the cytoplasmic membrane eight times, with the N and C termini in the cytoplasm. Moreover, a 310-amino-acid domain is present in the cytoplasm between the second and third transmembrane segments. It was deduced from the measurement of the MDO biosynthetic activity of truncated or fused MdoH proteins that almost all the C-terminal residues are necessary for this activity. The model of the MdoH protein in the membrane suggests that this protein could be directly involved in the translocation of nascent polyglucose chains to the periplasmic space.
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Affiliation(s)
- L Debarbieux
- Laboratoire de Chimie Biologique, UMR111 du CNRS, Université des Sciences et Technologies de Lille, Villeneuve d'Ascq, France
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Tang L, Weissborn AC, Kennedy EP. Domains of Escherichia coli acyl carrier protein important for membrane-derived-oligosaccharide biosynthesis. J Bacteriol 1997; 179:3697-705. [PMID: 9171419 PMCID: PMC179167 DOI: 10.1128/jb.179.11.3697-3705.1997] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Acyl carrier protein participates in a number of biosynthetic pathways in Escherichia coli: fatty acid biosynthesis, phospholipid biosynthesis, lipopolysaccharide biosynthesis, activation of prohemolysin, and membrane-derived oligosaccharide biosynthesis. The first four pathways require the protein's prosthetic group, phosphopantetheine, to assemble an acyl chain or to transfer an acyl group from the thioester linkage to a specific substrate. By contrast, the phosphopantetheine prosthetic group is not required for membrane-derived oligosaccharide biosynthesis, and the function of acyl carrier protein in this biosynthetic scheme is currently unknown. We have combined biochemical and molecular biological approaches to investigate domains of acyl carrier protein that are important for membrane-derived oligosaccharide biosynthesis. Proteolytic removal of the first 6 amino acids from acyl carrier protein or chemical synthesis of a partial peptide encompassing residues 26 to 50 resulted in losses of secondary and tertiary structure and consequent loss of activity in the membrane glucosyltransferase reaction of membrane-derived oligosaccharide biosynthesis. These peptide fragments, however, inhibited the action of intact acyl carrier protein in the enzymatic reaction. This suggests a role for the loop regions of the E. coli acyl carrier protein and the need for at least two regions of the protein for participation in the glucosyltransferase reaction. We have purified acyl carrier protein from eight species of Proteobacteria (including representatives from all four subgroups) and characterized the proteins as active or inhibitory in the membrane glucosyltransferase reaction. The complete or partial amino acid sequences of these acyl carrier proteins were determined. The results of site-directed mutagenesis to change amino acids conserved in active, and altered in inactive, acyl carrier proteins suggest the importance of residues Glu-4, Gln-14, Glu-21, and Asp-51. The first 3 of these residues define a face of acyl carrier protein that includes the beginning of the loop region, residues 16 to 36. Additionally, screening for membrane glucosyltransferase activity in membranes from bacterial species that had acyl carrier proteins that were active with E. coli membranes revealed the presence of glucosyltransferase activity only in the species most closely related to E. coli. Thus, it seems likely that only bacteria from the Proteobacteria subgroup gamma-3 have periplasmic glucans synthesized by the mechanism found in E. coli.
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Affiliation(s)
- L Tang
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA
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Lindgren PB. The role of hrp genes during plant-bacterial interactions. ANNUAL REVIEW OF PHYTOPATHOLOGY 1997; 35:129-52. [PMID: 15012518 DOI: 10.1146/annurev.phyto.35.1.129] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
hrp genes control the ability of phytopathogenic bacteria to cause disease and to elicit hypersensitive reactions on resistant plants. Genetic and biochemical studies have demonstrated that Hrp proteins are components of Type III secretion systems, regulatory proteins, proteinaceous elicitors of the hypersensitive reaction, and enzymes needed for synthesis of periplasmic glucans. Significantly, Type III secretion systems are involved with the secretion of pathogenicity proteins in bacterial pathogens of animals. The transcriptional activation of a number of bacterial avirulence (avr) genes is controlled by Hrp regulatory proteins, and recent experimental evidence suggests that Avr proteins may be transported by Hrp secretion systems. It has also been hypothesized that pathogenicity and/or virulence gene products exit bacterial phytopathogens via Hrp pathways. Thus, hrp genes may be one of the most important groups of genes found in phytopathogenic bacteria in relationship to pathogenicity and host range.
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Affiliation(s)
- P B Lindgren
- Department of Plant Pathology, North Carolina State University, Raleigh, North Carolina 27695-7616, USA.
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Lippens G, Wieruszeski JM, Talaga P, Bohin JP. Measurement of three-bond coupling constants in the osmoregulated periplasmic glucan of Burkholderia solanacearum. JOURNAL OF BIOMOLECULAR NMR 1996; 8:311-318. [PMID: 8953219 DOI: 10.1007/bf00410329] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The cyclic osmoregulated periplasmic glucan produced by Burkholderia solanacearum contains 13 glucose units, all beta-(1-2) linked except for one alpha-(1-6) linkage. We report here the measurement of the 3J(C1-H2') and 3J(H1-C2') coupling constants, characterizing the glycosidic linkages, through the use of a 13C/12C double half-filtered NOESY experiments. The values obtained give information about the (phi, psi) angles of the different linkages. The results presented from an important step towards a detailed experimental model of the cyclic glucan, which might allow us to clarify its biological role and establish whether the cavity of these molecules is compatible with the capability of complexing host molecular signals.
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Affiliation(s)
- G Lippens
- CNRS URA 1309, Pasteur Institute of Lille, France
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Abstract
The osmolality of rhizosphere soil water is expected to be elevated in relation to bulk-soil water osmolality as a result of the exclusion of solutes by plant roots during water uptake, the release of plant root exudates, and the production of exopolymers by plant roots and rhizobacteria. In contrast, the osmolality of water within highly hydrated bulk soil is low (less than 50 Osm/kg); thus the ability to adapt to elevated osmolality is likely to be important for successful rhizosphere colonization by rhizobacteria. The present review focuses on the osmoadaptive responses of three gram-negative rhizobacterial genera: Rhizobium, Azospirillum, and Pseudomonas. Specifically, we examine the compatible solutes and osmoprotectants utilized by various species within these genera. The adaptation of rhizobacteria to hypoosmotic environments is also examined in the present review. In particular, we focus on the biosynthesis and accumulation of periplasmic glucans by rhizobacteria. Finally, the relationship between rhizobacterial osmoadaptation and selected plant-microbe interactions is considered.
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Affiliation(s)
- K J Miller
- Department of Food Science, Pennsylvania State University, University Park 16802, USA
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Talaga P, Stahl B, Wieruszeski JM, Hillenkamp F, Tsuyumu S, Lippens G, Bohin JP. Cell-associated glucans of Burkholderia solanacearum and Xanthomonas campestris pv. citri: a new family of periplasmic glucans. J Bacteriol 1996; 178:2263-71. [PMID: 8636027 PMCID: PMC177934 DOI: 10.1128/jb.178.8.2263-2271.1996] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The cell-associated glucans produced by Burkholderia solanacearum and Xanthomonas campestris pv. citri were isolated by trichloroacetic acid treatment and gel permeation chromatography. The compounds obtained were characterized by compositional analysis, matrix-assisted laser desorption ionization mass spectrometry, and high-performance anion-exchange chromatography. B. solanacearum synthesizes only a neutral cyclic glucan containing 13 glucose residues, and X. campestris pv. citri synthesizes a neutral cyclic glucan containing 16 glucose residues. The two glucans were further purified by high-performance anion-exchange chromatography. Methylation analysis revealed that these glucans are linked by 1,2-glycosidic bonds and one 1,6-glycosidic bond. Our 600-MHz homonuclear and 1H-13C heteronuclear nuclear magnetic resonance experiments revealed the presence of a single alpha-1,6-glycosidic linkage, whereas all other glucose residues are beta-1,2 linked. The presence of this single alpha-1,6 linkage, however, induces such structural constraints in these cyclic glucans that all individual glucose residues could be distinguished. The different anomeric proton signals allowed complete sequence-specific assignment of both glucans. The structural characteristics of these glucans contrast with those of the previously described osmoregulated periplasmic glucans.
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Affiliation(s)
- P Talaga
- Laboratoire de Chimie Biologique, Centre National de la Recherche Scientifique UMR 11, Université des Sciences et Technologies de Lille, France
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