scholarly journals Substrate-Induced Production and Secretion of Cellulases by Clostridium acetobutylicum

2004 ◽  
Vol 70 (9) ◽  
pp. 5238-5243 ◽  
Author(s):  
Ana M. López-Contreras ◽  
Krisztina Gabor ◽  
Aernout A. Martens ◽  
Bernadet A. M. Renckens ◽  
Pieternel A. M. Claassen ◽  
...  
Keyword(s):  
Catabolite Repression ◽  
Clostridium Acetobutylicum ◽  
Glycoside Hydrolase ◽  
Protein A ◽  
Cellulase Activity ◽  
Glycoside Hydrolase Family ◽  
Extracellular Production ◽  
Encoding Genes ◽  
Glycoside Hydrolase Family 48 ◽  
Hydrolase Family

ABSTRACT Clostridium acetobutylicum ATCC 824 is a solventogenic bacterium that grows heterotrophically on a variety of carbohydrates, including glucose, cellobiose, xylose, and lichenan, a linear polymer of β-1,3- and β-1,4-linked β-d-glucose units. C. acetobutylicum does not degrade cellulose, although its genome sequence contains several cellulase-encoding genes and a complete cellulosome cluster of cellulosome genes. In the present study, we demonstrate that a low but significant level of induction of cellulase activity occurs during growth on xylose or lichenan. The celF gene, located in the cellulosome-like gene cluster and coding for a unique cellulase that belongs to glycoside hydrolase family 48, was cloned in Escherichia coli, and antibodies were raised against the overproduced CelF protein. A Western blot analysis suggested a possible catabolite repression by glucose or cellobiose and an up-regulation by lichenan or xylose of the extracellular production of CelF by C. acetobutylicum. Possible reasons for the apparent inability of C. acetobutylicum to degrade cellulose are discussed.

scholarly journals Tertiary Structure and Characterization of a Glycoside Hydrolase Family 44 Endoglucanase from Clostridium acetobutylicum

2009 ◽  
Vol 76 (1) ◽  
pp. 338-346 ◽  
Author(s):  
Christopher D. Warner ◽  
Julie A. Hoy ◽  
Taran C. Shilling ◽  
Michael J. Linnen ◽  
Nathaniel D. Ginder ◽  
...  
Keyword(s):  
Clostridium Acetobutylicum ◽  
Glycoside Hydrolase ◽  
Tertiary Structure ◽  
Nitrilotriacetic Acid ◽  
Product Distribution ◽  
Glycoside Hydrolase Family ◽  
Uncharacterized Protein ◽  
Gene Encoding ◽  
Tim Barrel ◽  
Hydrolase Family

ABSTRACT A gene encoding a glycoside hydrolase family 44 (GH44) protein from Clostridium acetobutylicum ATCC 824 was synthesized and transformed into Escherichia coli. The previously uncharacterized protein was expressed with a C-terminal His tag and purified by nickel-nitrilotriacetic acid affinity chromatography. Crystallization and X-ray diffraction to a 2.2-Å resolution revealed a triose phosphate isomerase (TIM) barrel-like structure with additional Greek key and β-sandwich folds, similar to other GH44 crystal structures. The enzyme hydrolyzes cellotetraose and larger cellooligosaccharides, yielding an unbalanced product distribution, including some glucose. It attacks carboxymethylcellulose and xylan at approximately the same rates. Its activity on carboxymethylcellulose is much higher than that of the isolated C. acetobutylicum cellulosome. It also extensively converts lichenan to oligosaccharides of intermediate size and attacks Avicel to a limited extent. The enzyme has an optimal temperature in a 10-min assay of 55°C and an optimal pH of 5.0.

scholarly journals Sequence, Structure, and Evolution of Cellulases in Glycoside Hydrolase Family 48

2012 ◽  
Vol 287 (49) ◽  
pp. 41068-41077 ◽  
Author(s):  
Leonid O. Sukharnikov ◽  
Markus Alahuhta ◽  
Roman Brunecky ◽  
Amit Upadhyay ◽  
Michael E. Himmel ◽  
...  
Keyword(s):  
Glycoside Hydrolase ◽  
Glycoside Hydrolase Family ◽  
Sequence Structure ◽  
Glycoside Hydrolase Family 48 ◽  
Hydrolase Family

scholarly journals Natural diversity of glycoside hydrolase family 48 exoglucanases: insights from structure

2017 ◽  
Vol 10 (1) ◽  
Author(s):  
Roman Brunecky ◽  
Markus Alahuhta ◽  
Deanne W. Sammond ◽  
Qi Xu ◽  
Mo Chen ◽  
...  
Keyword(s):  
Glycoside Hydrolase ◽  
Glycoside Hydrolase Family ◽  
Natural Diversity ◽  
Glycoside Hydrolase Family 48 ◽  
Hydrolase Family

Xylanases of glycoside hydrolase family 30 – An overview

2021 ◽  
Vol 47 ◽  
pp. 107704
Author(s):  
Vladimír Puchart ◽  
Katarína Šuchová ◽  
Peter Biely
Keyword(s):  
Glycoside Hydrolase ◽  
Glycoside Hydrolase Family ◽  
Hydrolase Family ◽  
Glycoside Hydrolase Family 30

scholarly journals Modeled 3D-Structures of Proteobacterial Transglycosylases from Glycoside Hydrolase Family 17 Give Insight in Ligand Interactions Explaining Differences in Transglycosylation Products

2021 ◽  
Vol 11 (9) ◽  
pp. 4048
Author(s):  
Javier A. Linares-Pastén ◽  
Lilja Björk Jonsdottir ◽  
Gudmundur O. Hreggvidsson ◽  
Olafur H. Fridjonsson ◽  
Hildegard Watzlawick ◽  
...  
Keyword(s):  
Glycoside Hydrolase ◽  
Ligand Docking ◽  
Glycoside Hydrolase Family ◽  
Ligand Interactions ◽  
Tim Barrel ◽  
Branching Point ◽  
The Difference ◽  
Dynamics Simulations ◽  
And Function ◽  
Hydrolase Family

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.

scholarly journals Understanding the Polymerization Mechanism of Glycoside-Hydrolase Family 70 Glucansucrases

2006 ◽  
Vol 281 (42) ◽  
pp. 31254-31267
Author(s):  
Claire Moulis ◽  
Gilles Joucla ◽  
David Harrison ◽  
Emeline Fabre ◽  
Gabrielle Potocki-Veronese ◽  
...  
Keyword(s):  
Glycoside Hydrolase ◽  
Glycoside Hydrolase Family ◽  
Polymerization Mechanism ◽  
Hydrolase Family
Sign in / Sign up

Export Citation Format

Share Document