scholarly journals Engineering the Xylan Utilization System in Bacillus subtilis for Production of Acidic Xylooligosaccharides

2013 ◽  
Vol 80 (3) ◽  
pp. 917-927 ◽  
Author(s):  
Mun Su Rhee ◽  
Lusha Wei ◽  
Neha Sawhney ◽  
John D. Rice ◽  
Franz J. St. John ◽  
...  

ABSTRACTXylans are the predominant polysaccharides in hemicelluloses and an important potential source of biofuels and chemicals. The ability ofBacillus subtilissubsp.subtilisstrain 168 to utilize xylans has been ascribed to secreted glycoside hydrolase family 11 (GH11) and GH30 endoxylanases, encoded by thexynAandxynCgenes, respectively. Both of these enzymes have been defined with respect to structure and function. In this study, the effects of deletion of thexynAandxynCgenes, individually and in combination, were evaluated for xylan utilization and formation of acidic xylooligosaccharides. Parent strain 168 depolymerizes methylglucuronoxylans (MeGXn), releasing the xylobiose and xylotriose utilized for growth and accumulating the aldouronate methylglucuronoxylotriose (MeGX3) with some methylglucuronoxylotetraose (MeGX4). The combined GH11 and GH30 activities process the products generated by their respective actions on MeGXnto release a maximal amount of neutral xylooligosaccharides for assimilation and growth, at the same time forming MeGX3in which the internal xylose is substituted with methylglucuronate (MeG). Deletion ofxynAresults in the accumulation of β-1,4-xylooligosaccharides with degrees of polymerization ranging from 4 to 18 and an average degree of substitution of 1 in 7.2, each with a single MeG linked α-1,2 to the xylose penultimate to the xylose at the reducing terminus. Deletion of thexynCgene results in the accumulation of aldouronates comprised of 4 or more xylose residues in which the MeG may be linked α-1,2 to the xylose penultimate to the nonreducing xylose. TheseB. subtilislines may be used for the production of acidic xylooligosaccharides with applications in human and veterinary medicine.

Biochemistry ◽  
2010 ◽  
Vol 49 (15) ◽  
pp. 3305-3316 ◽  
Author(s):  
Paul V. Harris ◽  
Ditte Welner ◽  
K. C. McFarland ◽  
Edward Re ◽  
Jens-Christian Navarro Poulsen ◽  
...  

FEBS Journal ◽  
2014 ◽  
Vol 281 (18) ◽  
pp. 4165-4178 ◽  
Author(s):  
Alessandro S. Nascimento ◽  
Joao Renato C. Muniz ◽  
Ricardo Aparício ◽  
Alexander M. Golubev ◽  
Igor Polikarpov

2021 ◽  
Vol 11 (9) ◽  
pp. 4048
Author(s):  
Javier A. Linares-Pastén ◽  
Lilja Björk Jonsdottir ◽  
Gudmundur O. Hreggvidsson ◽  
Olafur H. Fridjonsson ◽  
Hildegard Watzlawick ◽  
...  

The structures of glycoside hydrolase family 17 (GH17) catalytic modules from modular proteins in the ndvB loci in Pseudomonas aeruginosa (Glt1), P. putida (Glt3) and Bradyrhizobium diazoefficiens (previously B. japonicum) (Glt20) were modeled to shed light on reported differences between these homologous transglycosylases concerning substrate size, preferred cleavage site (from reducing end (Glt20: DP2 product) or non-reducing end (Glt1, Glt3: DP4 products)), branching (Glt20) and linkage formed (1,3-linkage in Glt1, Glt3 and 1,6-linkage in Glt20). Hybrid models were built and stability of the resulting TIM-barrel structures was supported by molecular dynamics simulations. Catalytic amino acids were identified by superimposition of GH17 structures, and function was verified by mutagenesis using Glt20 as template (i.e., E120 and E209). Ligand docking revealed six putative subsites (−4, −3, −2, −1, +1 and +2), and the conserved interacting residues suggest substrate binding in the same orientation in all three transglycosylases, despite release of the donor oligosaccharide product from either the reducing (Glt20) or non-reducing end (Glt1, Gl3). Subsites +1 and +2 are most conserved and the difference in release is likely due to changes in loop structures, leading to loss of hydrogen bonds in Glt20. Substrate docking in Glt20 indicate that presence of covalently bound donor in glycone subsites −4 to −1 creates space to accommodate acceptor oligosaccharide in alternative subsites in the catalytic cleft, promoting a branching point and formation of a 1,6-linkage. The minimum donor size of DP5, can be explained assuming preferred binding of DP4 substrates in subsite −4 to −1, preventing catalysis.


2016 ◽  
Vol 82 (14) ◽  
pp. 4340-4349 ◽  
Author(s):  
Damao Wang ◽  
Do Hyoung Kim ◽  
Nari Seo ◽  
Eun Ju Yun ◽  
Hyun Joo An ◽  
...  

ABSTRACTIn this study, we characterized Gly5M, originating from a marine bacterium, as a novel β-1,3-1,6-endoglucanase in glycoside hydrolase family 5 (GH5) in the Carbohydrate-Active enZyme database. Thegly5Mgene encodes Gly5M, a newly characterized enzyme from GH5 subfamily 47 (GH5_47) inSaccharophagus degradans2-40T. Thegly5Mgene was cloned and overexpressed inEscherichia coli. Through analysis of the enzymatic reaction products by thin-layer chromatography, high-performance liquid chromatography, and matrix-assisted laser desorption ionization–tandem time of flight mass spectrometry, Gly5M was identified as a novel β-1,3-endoglucanase (EC 3.2.1.39) and bacterial β-1,6-glucanase (EC 3.2.1.75) in GH5. The β-1,3-endoglucanase and β-1,6-endoglucanase activities were detected by using laminarin (a β-1,3-glucan with β-1,6-glycosidic linkages derived from brown macroalgae) and pustulan (a β-1,6-glucan derived from fungal cell walls) as the substrates, respectively. This enzyme also showed transglycosylase activity toward β-1,3-oligosaccharides when laminarioligosaccharides were used as the substrates. Since laminarin is the major form of glucan storage in brown macroalgae, Gly5M could be used to produce glucose and laminarioligosaccharides, using brown macroalgae, for industrial purposes.IMPORTANCEIn this study, we have discovered a novel β-1,3-1,6-endoglucanase with a unique transglycosylase activity, namely, Gly5M, from a marine bacterium,Saccharophagus degradans2-40T. Gly5M was identified as the newly found β-1,3-endoglucanase and bacterial β-1,6-glucanase in GH5. Gly5M is capable of cleaving glycosidic linkages of both β-1,3-glucans and β-1,6-glucans. Gly5M also possesses a transglycosylase activity toward β-1,3-oligosacchrides. Due to the broad specificity of Gly5M, this enzyme can be used to produce glucose or high-value β-1,3- and/or β-1,6-oligosaccharides.


2020 ◽  
Vol 6 (10) ◽  
Author(s):  
Ao Li ◽  
Elisabeth Laville ◽  
Laurence Tarquis ◽  
Vincent Lombard ◽  
David Ropartz ◽  
...  

Mannoside phosphorylases are involved in the intracellular metabolization of mannooligosaccharides, and are also useful enzymes for the in vitro synthesis of oligosaccharides. They are found in glycoside hydrolase family GH130. Here we report on an analysis of 6308 GH130 sequences, including 4714 from the human, bovine, porcine and murine microbiomes. Using sequence similarity networks, we divided the diversity of sequences into 15 mostly isofunctional meta-nodes; of these, 9 contained no experimentally characterized member. By examining the multiple sequence alignments in each meta-node, we predicted the determinants of the phosphorolytic mechanism and linkage specificity. We thus hypothesized that eight uncharacterized meta-nodes would be phosphorylases. These sequences are characterized by the absence of signal peptides and of the catalytic base. Those sequences with the conserved E/K, E/R and Y/R pairs of residues involved in substrate binding would target β-1,2-, β-1,3- and β-1,4-linked mannosyl residues, respectively. These predictions were tested by characterizing members of three of the uncharacterized meta-nodes from gut bacteria. We discovered the first known β-1,4-mannosyl-glucuronic acid phosphorylase, which targets a motif of the Shigella lipopolysaccharide O-antigen. This work uncovers a reliable strategy for the discovery of novel mannoside-phosphorylases, reveals possible interactions between gut bacteria, and identifies a biotechnological tool for the synthesis of antigenic oligosaccharides.


2008 ◽  
Vol 30 (5) ◽  
pp. 911-918 ◽  
Author(s):  
Dong-Geun Lee ◽  
Min Kyung Jang ◽  
Ok-Hee Lee ◽  
Nam Young Kim ◽  
Seong-A Ju ◽  
...  

2013 ◽  
Vol 79 (19) ◽  
pp. 5788-5798 ◽  
Author(s):  
Chang-Hao Cui ◽  
Qing-Mei Liu ◽  
Jin-Kwang Kim ◽  
Bong-Hyun Sung ◽  
Song-Gun Kim ◽  
...  

ABSTRACTHere, we isolated and characterized a new ginsenoside-transforming β-glucosidase (BglQM) fromMucilaginibactersp. strain QM49 that shows biotransformation activity for various major ginsenosides. The gene responsible for this activity,bglQM, consists of 2,346 bp and is predicted to encode 781 amino acid residues. This enzyme has a molecular mass of 85.6 kDa. Sequence analysis of BglQM revealed that it could be classified into glycoside hydrolase family 3. The enzyme was overexpressed inEscherichia coliBL21(DE3) using a maltose binding protein (MBP)-fused pMAL-c2x vector system containing the tobacco etch virus (TEV) proteolytic cleavage site. Overexpressed recombinant BglQM could efficiently transform the protopanaxatriol-type ginsenosides Re and Rg1into (S)-Rg2and (S)-Rh1, respectively, by hydrolyzing one glucose moiety attached to the C-20 position at pH 8.0 and 30°C. TheKmvalues forp-nitrophenyl-β-d-glucopyranoside, Re, and Rg1were 37.0 ± 0.4 μM and 3.22 ± 0.15 and 1.48 ± 0.09 mM, respectively, and theVmaxvalues were 33.4 ± 0.6 μmol min−1mg−1of protein and 19.2 ± 0.2 and 28.8 ± 0.27 nmol min−1mg−1of protein, respectively. A crude protopanaxatriol-type ginsenoside mixture (PPTGM) was treated with BglQM, followed by silica column purification, to produce (S)-Rh1and (S)-Rg2at chromatographic purities of 98% ± 0.5% and 97% ± 1.2%, respectively. This is the first report of gram-scale production of (S)-Rh1and (S)-Rg2from PPTGM using a novel ginsenoside-transforming β-glucosidase of glycoside hydrolase family 3.


2015 ◽  
Vol 81 (20) ◽  
pp. 7223-7232 ◽  
Author(s):  
Yuxiang Bai ◽  
Rachel Maria van der Kaaij ◽  
Hans Leemhuis ◽  
Tjaard Pijning ◽  
Sander Sebastiaan van Leeuwen ◽  
...  

ABSTRACT4,6-α-Glucanotransferase (4,6-α-GTase) enzymes, such as GTFB and GTFW ofLactobacillus reuteristrains, constitute a new reaction specificity in glycoside hydrolase family 70 (GH70) and are novel enzymes that convert starch or starch hydrolysates into isomalto/maltopolysaccharides (IMMPs). These IMMPs still have linear chains with some α1→4 linkages but mostly (relatively long) linear chains with α1→6 linkages and are soluble dietary starch fibers. 4,6-α-GTase enzymes and their products have significant potential for industrial applications. Here we report that an N-terminal truncation (amino acids 1 to 733) strongly enhances the soluble expression level of fully active GTFB-ΔN (approximately 75-fold compared to full-length wild type GTFB) inEscherichia coli. In addition, quantitative assays based on amylose V as the substrate are described; these assays allow accurate determination of both hydrolysis (minor) activity (glucose release, reducing power) and total activity (iodine staining) and calculation of the transferase (major) activity of these 4,6-α-GTase enzymes. The data show that GTFB-ΔN is clearly less hydrolytic than GTFW, which is also supported by nuclear magnetic resonance (NMR) analysis of their final products. From these assays, the biochemical properties of GTFB-ΔN were characterized in detail, including determination of kinetic parameters and acceptor substrate specificity. The GTFB enzyme displayed high conversion yields at relatively high substrate concentrations, a promising feature for industrial application.


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