scholarly journals A modular cinnamoyl ester hydrolase from the anaerobic fungus Piromyces equi acts synergistically with xylanase and is part of a multiprotein cellulose-binding cellulase‒hemicellulase complex

1999 ◽  
Vol 343 (1) ◽  
pp. 215 ◽  
Author(s):  
Ian J. FILLINGHAM ◽  
Paul A. KROON ◽  
Gary WILLIAMSON ◽  
Harry J. GILBERT ◽  
Geoffrey P. HAZLEWOOD
Keyword(s):  
Anaerobic Fungus ◽  
Ester Hydrolase ◽  
Cellulose Binding

scholarly journals A mannanase, ManA, of the polycentric anaerobic fungusOrpinomycessp. strain PC-2 has carbohydrate binding and docking modules

2005 ◽  
Vol 51 (7) ◽  
pp. 559-568 ◽  
Author(s):  
Eduardo A Ximenes ◽  
Huizhong Chen ◽  
Irina A Kataeva ◽  
Michael A Cotta ◽  
Carlos R Felix ◽  
...  
Keyword(s):  
Specific Activity ◽  
High Specific Activity ◽  
Glycoside Hydrolases ◽  
Carbohydrate Binding ◽  
Carbohydrate Binding Module ◽  
Amino Acid Residues ◽  
Anaerobic Fungus ◽  
Ph Profile ◽  
Catalytic Module ◽  
Cellulose Binding

The anaerobic fungus Orpinomyces sp. strain PC-2 produces a broad spectrum of glycoside hydrolases, most of which are components of a high molecular mass cellulosomal complex. Here we report about a cDNA (manA) having 1924 bp isolated from the fungus and found to encode a polypeptide of 579 amino acid residues. Analysis of the deduced sequence revealed that it had a mannanase catalytic module, a family 1 carbohydrate-binding module, and a noncatalytic docking module. The catalytic module was homologous to aerobic fungal mannanases belonging to family 5 glycoside hydrolases, but unrelated to the previously isolated mannanases (family 26) of the anaerobic fungus Piromyces. No mannanase activity could be detected in Escherichia coli harboring a manA-containing plasmid. The manA was expressed in Saccharomyces cerevisiae and ManA was secreted into the culture medium in multiple forms. The purified extracellular heterologous mannanase hydrolyzed several types of mannan but lacked activity against cellulose, chitin, or β-glucan. The enzyme had high specific activity toward locust bean mannan and an extremely broad pH profile. It was stable for several hours at 50 °C, but was rapidly inactivated at 60 °C. The carbohydrate-binding module of the Man A produced separately in E. coli bound preferably to insoluble lignocellulosic substrates, suggesting that it might play an important role in the complex enzyme system of the fungus for lignocellulose degradation.Key words: Orpinomyces, anaerobic fungi, mannanase, cellulose-binding module, cellulosome.

Characterization of sterol-ester hydrolase in Saccharomyces cerevisiae

1978 ◽  
Vol 525 (1) ◽  
pp. 87-92 ◽  
Author(s):  
Shigeru Taketani ◽  
Takashi Osumi ◽  
Hirohiko Katsuki
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Sterol Ester ◽  
Ester Hydrolase

scholarly journals Spontaneous Cleavages of a Heterologous Protein, the CenA Endoglucanase of Cellulomonas fimi, in Escherichia coli

2021 ◽  
Vol 14 ◽  
pp. 117863612110246
Author(s):  
Cheuk Yin Lai ◽  
Ka Lun Ng ◽  
Hao Wang ◽  
Chui Chi Lam ◽  
Wan Keung Raymond Wong
Keyword(s):  
Escherichia Coli ◽  
Cellulolytic Bacterium ◽  
Systematic Screening ◽  
Cellulomonas Fimi ◽  
E Coli ◽  
Substrate Complex ◽  
Enzyme Substrate ◽  
Glycosylation Sites ◽  
Endogenous Proteins ◽  
Cellulose Binding

CenA is an endoglucanase secreted by the Gram-positive cellulolytic bacterium, Cellulomonas fimi, to the environment as a glycosylated protein. The role of glycosylation in CenA is unclear. However, it seems not crucial for functional activity and secretion since the unglycosylated counterpart, recombinant CenA (rCenA), is both bioactive and secretable in Escherichia coli. Using a systematic screening approach, we have demonstrated that rCenA is subjected to spontaneous cleavages (SC) in both the cytoplasm and culture medium of E. coli, under the influence of different environmental factors. The cleavages were found to occur in both the cellulose-binding (CellBD) and catalytic domains, with a notably higher occurring rate detected in the former than the latter. In CellBD, the cleavages were shown to occur close to potential N-linked glycosylation sites, suggesting that these sites might serve as ‘attributive tags’ for differentiating rCenA from endogenous proteins and the points of initiation of SC. It is hypothesized that glycosylation plays a crucial role in protecting CenA from SC when interacting with cellulose in the environment. Subsequent to hydrolysis, SC would ensure the dissociation of CenA from the enzyme-substrate complex. Thus, our findings may help elucidate the mechanisms of protein turnover and enzymatic cellulolysis.

scholarly journals Carnitine Ester Hydrolase of Rat Liver

1969 ◽  
Vol 244 (16) ◽  
pp. 4448-4453
Author(s):  
S Mahadevan ◽  
F Sauer
Keyword(s):  
Rat Liver ◽  
Ester Hydrolase
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