Crystal structures of glycoside hydrolase family 3 β-glucosidase 1 from Aspergillus aculeatus

2013 ◽  
Vol 452 (2) ◽  
pp. 211-221 ◽  
Author(s):  
Kentaro Suzuki ◽  
Jun-Ichi Sumitani ◽  
Young-Woo Nam ◽  
Toru Nishimaki ◽  
Shuji Tani ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Glycoside Hydrolase ◽  
Degree Of Polymerization ◽  
Cellulosic Biomass ◽  
Protein Crystal ◽  
Structural Basis ◽  
Glycoside Hydrolase Family ◽  
Aspergillus Aculeatus ◽  
Technical Improvement ◽  
Hydrolase Family

GH3 (glycoside hydrolase family 3) BGLs (β-glucosidases) from filamentous fungi have been widely and commercially used for the supplementation of cellulases. AaBGL1 (Aspergillus aculeatus BGL1) belongs to the GH3 and shows high activity towards cellooligosaccharides up to high degree of polymerization. In the present study we determined the crystal structure of AaBGL1. In addition to the substrate-free structure, the structures of complexes with glucose and various inhibitors were determined. The structure of AaBGL1 is highly glycosylated with 88 monosaccharides (18 N-glycan chains) in the dimer. The largest N-glycan chain comprises ten monosaccharides and is one of the largest glycans ever observed in protein crystal structures. A prominent insertion region exists in a fibronectin type III domain, and this region extends to cover a wide surface area of the enzyme. The subsite +1 of AaBGL1 is highly hydrophobic. Three aromatic residues are present at subsite +1 and are located in short loop regions that are uniquely present in this enzyme. There is a long cleft extending from subsite +1, which appears to be suitable for binding long cellooligosaccharides. The crystal structures of AaBGL1 from the present study provide an important structural basis for the technical improvement of enzymatic cellulosic biomass conversion.

scholarly journals The structure of PfGH50B, an agarase from the marine bacterium Pseudoalteromonas fuliginea PS47

2020 ◽  
Vol 76 (9) ◽  
pp. 422-427
Author(s):  
Benjamin Pluvinage ◽  
Craig S. Robb ◽  
Roderick Jeffries ◽  
Alisdair B. Boraston
Keyword(s):  
Glycoside Hydrolase ◽  
Marine Bacterium ◽  
Structural Features ◽  
Degree Of Polymerization ◽  
Glycoside Hydrolase Family ◽  
Carbohydrate Binding ◽  
X Ray ◽  
Terminal Domain ◽  
Polysaccharide Utilization Locus ◽  
Hydrolase Family

The recently identified marine bacterium Pseudoalteromonas fuliginea sp. PS47 possesses a polysaccharide-utilization locus dedicated to agarose degradation. In particular, it contains a gene (locus tag EU509_06755) encoding a β-agarase that belongs to glycoside hydrolase family 50 (GH50), PfGH50B. The 2.0 Å resolution X-ray crystal structure of PfGH50B reveals a rare complex multidomain fold that was found in two of the three previously determined GH50 structures. The structure comprises an N-terminal domain with a carbohydrate-binding module (CBM)-like fold fused to a C-terminal domain by a rigid linker. The CBM-like domain appears to function by extending the catalytic groove of the enzyme. Furthermore, the PfGH50B structure highlights key structural features in the mobile loops that may function to restrict the degree of polymerization of the neoagaro-oligosaccharide products and the enzyme processivity.

Crystal structures of the GH6 Orpinomyces sp. Y102 CelC7 enzyme with exo and endo activity and its complex with cellobiose

2019 ◽  
Vol 75 (12) ◽  
pp. 1138-1147
Author(s):  
Hsiao-Chuan Huang ◽  
Liu-Hong Qi ◽  
Yo-Chia Chen ◽  
Li-Chu Tsai
Keyword(s):  
Enzymatic Hydrolysis ◽  
Crystal Structures ◽  
Active Site ◽  
Binding Sites ◽  
Glycoside Hydrolase ◽  
Catalytic Domain ◽  
Glycoside Hydrolase Family ◽  
Substrate Binding Sites ◽  
Key Residues ◽  
Hydrolase Family

The catalytic domain (residues 128–449) of the Orpinomyces sp. Y102 CelC7 enzyme (Orp CelC7) exhibits cellobiohydrolase and cellotriohydrolase activities. Crystal structures of Orp CelC7 and its cellobiose-bound complex have been solved at resolutions of 1.80 and 2.78 Å, respectively. Cellobiose occupies subsites +1 and +2 within the active site of Orp CelC7 and forms hydrogen bonds to two key residues: Asp248 and Asp409. Furthermore, its substrate-binding sites have both tunnel-like and open-cleft conformations, suggesting that the glycoside hydrolase family 6 (GH6) Orp CelC7 enzyme may perform enzymatic hydrolysis in the same way as endoglucanases and cellobiohydrolases. LC-MS/MS analysis revealed cellobiose (major) and cellotriose (minor) to be the respective products of endo and exo activity of the GH6 Orp CelC7.

scholarly journals Structural and functional studies of the glycoside hydrolase family 3 β-glucosidase Cel3A from the moderately thermophilic fungusRasamsonia emersonii

2016 ◽  
Vol 72 (7) ◽  
pp. 860-870 ◽  
Author(s):  
Mikael Gudmundsson ◽  
Henrik Hansson ◽  
Saeid Karkehabadi ◽  
Anna Larsson ◽  
Ingeborg Stals ◽  
...  
Keyword(s):  
Glycoside Hydrolase ◽  
Biochemical Characterization ◽  
Cellulosic Biomass ◽  
Glycoside Hydrolase Family ◽  
Hypocrea Jecorina ◽  
Moderately Thermophilic ◽  
Functional Studies ◽  
Excellent Candidate ◽  
Hydrolase Family

The filamentous fungusHypocrea jecorinaproduces a number of cellulases and hemicellulases that act in a concerted fashion on biomass and degrade it into monomeric or oligomeric sugars. β-Glucosidases are involved in the last step of the degradation of cellulosic biomass and hydrolyse the β-glycosidic linkage between two adjacent molecules in dimers and oligomers of glucose. In this study, it is shown that substituting the β-glucosidase fromH. jecorina(HjCel3A) with the β-glucosidase Cel3A from the thermophilic fungusRasamsonia emersonii(ReCel3A) in enzyme mixtures results in increased efficiency in the saccharification of lignocellulosic materials. Biochemical characterization ofReCel3A, heterologously produced inH. jecorina, reveals a preference for disaccharide substrates over longer gluco-oligosaccharides. Crystallographic studies ofReCel3A revealed a highly N-glycosylated three-domain dimeric protein, as has been observed previously for glycoside hydrolase family 3 β-glucosidases. The increased thermal stability and saccharification yield and the superior biochemical characteristics ofReCel3A compared withHjCel3A and mixtures containingHjCel3A makeReCel3A an excellent candidate for addition to enzyme mixtures designed to operate at higher temperatures.

scholarly journals Thermostable mutants of glycoside hydrolase family 6 cellobiohydrolase from the basidiomycete Phanerochaete chrysosporium

2020 ◽  
Author(s):  
Sora Yamaguchi ◽  
Naoki Sunagawa ◽  
Mikako Tachioka ◽  
Kiyohiko Igarashi ◽  
Masahiro Samejima
Keyword(s):  
Thermal Stability ◽  
Phanerochaete Chrysosporium ◽  
Glycoside Hydrolase ◽  
Thermal Inactivation ◽  
Renewable Resource ◽  
Cellulosic Biomass ◽  
Limiting Factor ◽  
Glycoside Hydrolase Family ◽  
Hydrolytic Activities ◽  
Hydrolase Family

AbstractThermal inactivation of saccharifying enzymes is a crucial issue for the efficient utilization of cellulosic biomass as a renewable resource. Cellobiohydrolases (CBHs) is a kind of cellulase. In general, CBHs belonging to glycoside hydrolase (GH) family 6 (Cel6) act synergistically with CBHs of GH family 7 (Cel7) and other carbohydrate-active enzymes during the degradation of cellulosic biomass. However, while the catalytic rate of enzymes generally becomes faster at higher temperatures, Cel6 CBHs are inactivated at lower temperatures than Cel7 CBHs, and this represents a limiting factor for industrial utilization. In this study, we produced a series of mutants of the glycoside hydrolase family 6 cellobiohydrolase PcCel6A from the fungus Phanerochaete chrysosporium, and compared their thermal stability. Eight mutants from a random mutagenesis library and one rationally designed mutant were selected as candidate thermostable mutants and produced by heterologous expression in the yeast Pichia pastoris. Comparison of the hydrolytic activities at 50 and 60 °C indicated that the thermal stability of PcCel6A is influenced by the number and position of cysteine residues that are not involved in disulfide bonds.

scholarly journals Structural basis of catalysis and substrate recognition by the NAD(H)-dependent α-d-glucuronidase from the glycoside hydrolase family 4

2021 ◽  
Vol 478 (4) ◽  
pp. 943-959
Author(s):  
Samar Ballabha Mohapatra ◽  
Narayanan Manoj
Keyword(s):  
Conformational Changes ◽  
Active Site ◽  
Glycoside Hydrolase ◽  
Metal Ion ◽  
Substrate Recognition ◽  
Structural Basis ◽  
Glycoside Hydrolase Family ◽  
Diverse Range ◽  
Molecular Features ◽  
Hydrolase Family

Members of the glycoside hydrolase family 4 (GH4) employ an unusual glycosidic bond cleavage mechanism utilizing NAD(H) and a divalent metal ion, under reducing conditions. These enzymes act upon a diverse range of glycosides, and unlike most other GH families, homologs here are known to accommodate both α- and β-anomeric specificities within the same active site. Here, we report the catalytic properties and the crystal structures of TmAgu4B, an α-d-glucuronidase from the hyperthermophile Thermotoga maritima. The structures in three different states include the apo form, the NADH bound holo form, and the ternary complex with NADH and the reaction product d-glucuronic acid, at 2.15, 1.97 and 1.85 Å resolutions, respectively. These structures reveal the step-wise route of conformational changes required in the active site to achieve the catalytically competent state, and illustrate the direct role of residues that determine the reaction mechanism. Furthermore, a structural transition of a helical region in the active site to a turn geometry resulting in the rearrangement of a unique arginine residue governs the exclusive glucopyranosiduronic acid recognition in TmAgu4B. Mutational studies show that modifications of the glycone binding site geometry lead to catalytic failure and indicate overlapping roles of specific residues in catalysis and substrate recognition. The data highlight hitherto unreported molecular features and associated active site dynamics that determine the structure–function relationships within the unique GH4 family.

scholarly journals Crystal Structures of a Glycoside Hydrolase Family 20 Lacto-N-biosidase fromBifidobacterium bifidum

2013 ◽  
Vol 288 (17) ◽  
pp. 11795-11806 ◽  
Author(s):  
Tasuku Ito ◽  
Takane Katayama ◽  
Mitchell Hattie ◽  
Haruko Sakurama ◽  
Jun Wada ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Glycoside Hydrolase ◽  
Glycoside Hydrolase Family ◽  
Hydrolase Family

Crystal Structures of Glycoside Hydrolase Family 51 α-L-Arabinofuranosidase fromThermotoga maritima

2012 ◽  
Vol 76 (2) ◽  
pp. 423-428 ◽  
Author(s):  
Do-Hyun IM ◽  
Kei-ichi KIMURA ◽  
Fumitaka HAYASAKA ◽  
Tomonari TANAKA ◽  
Masato NOGUCHI ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Glycoside Hydrolase ◽  
Glycoside Hydrolase Family ◽  
Hydrolase Family ◽  
Glycoside Hydrolase Family 51
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