Bacterial cellulases

Béguin, Pierre; Millet, J; Chauvaux, Sylvie; Salamitou, Sylvie; Tokatlidis, Kostas; Navas, Jesús; Fujino, Tsuchiyoshi; Lemaire, Marc; Raynaud, Odette; Daniel, Marie-Kim; Aubert, Jean-Paul

doi:10.1042/bst0200042

Cited by 32 publications

(15 citation statements)

References 1 publication

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“…cellulosa (13), and the endoglucanase from avocado (31) in family E of cellulases and related enzymes (2,15). Sequence similarities alone, however, place CelD and Egl in subfamily E1 and the avocado enzyme in subfamily E2 (2).…”

Section: Resultsmentioning

confidence: 99%

“…The three C. fimi cellulases characterized to date belong to three different catalytic domain families; CenA belongs to family B, CenB belongs to family E, and Cex belongs to family F (2,15). However, they all have the same type of CBD.…”

Section: Resultsmentioning

confidence: 99%

“…Such diversity and conservation within the cellulases of a microorganism may be quite common. C. thermocellum produces endoglucanases belonging to families A, D, and E which have the same repeated sequence of 24 amino acids (2), and T. reesei produces cellulases belonging to families A, B, and C which have similar CBDs and linkers (2,15,17). It is clear that many cellulases arose by shuffling of a limited number of progenitor sequences.…”

Section: Resultsmentioning

confidence: 99%

“…It is clear that many cellulases arose by shuffling of a limited number of progenitor sequences. Families A, B, and F contain fungal and bacterial enzymes, and family E contains bacterial enzymes and a plant enzyme(s) (2,15).…”

Section: Resultsmentioning

confidence: 99%

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Unusual sequence organization in CenB, an inverting endoglucanase from Cellulomonas fimi

et al. 1991

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The nucleotide sequence of the cenB gene was determined and used to deduce the amino acid sequence of endoglucanase B (CenB) of Cellulomonasfimi. CenB comprises 1,012 amino acids and has a molecular weight of 105,905. The polypeptide is divided by so-called linker sequences rich in proline and hydroxyamino acids into five domains: a catalytic domain of 607 amino acids at the N terminus, followed by three repeats of 98 amino acids each which are >60% identical, and a C-terminal domain of 101 amino acids which is 50% identical to the cellulose-binding domains of C. fimi cellulases Cex and CenA. A deletion mutant of the cenB gene encodes a polypeptide lacking the C-terminal 333 amino acids of CenB. The truncated polypeptide is catalytically active and, like intact CenB, binds to cellulose, suggesting that CenB has a second cellulosebinding site. The sequence of amino acids 1 to 461 of CenB is 35% identical, with a further 15% similarity, to that of a cellulase from avocado, which places CenB in cellulase family E. CenB releases mostly cellobiose and cellotetraose from cellohexaose. Like CenA, CenB hydrolyzes the ,3-1,4-glucosidic bond with inversion of the anomeric configuration. The pH optimum for CenB is 8.5, and that for CenA is 7.5.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Unusual sequence organization in CenB, an inverting endoglucanase from Cellulomonas fimi

et al. 1991

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“…The microorganisms are capable of producing different cellulolytic enzymes such as endoglucanase, β-glucosidase and cellobiohydrolase [5]. Several bacteria such as Geobacillus sp., Bacillus licheniformis, Cellulomonas cellulans, Clostridium thermocellum and Staphylococcus aureus have been reported for the production of cellulolytic enzymes [6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Bioprospecting of Thermostable Cellulolytic Enzymes through Modeling and Virtual Screening Method

Krishnaraj¹,

Samanta²,

Kumar³

et al. 2017

Can J Biotech

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Cellulolytic enzymes are promising candidates for the use of cellulose in any bioprocess operations and for the disposal of the cellulosic wastes in an environmentally benign manner. Cellulases from thermophiles have the advantage of hydrolyzing cellulose at wider range of operating conditions unlike the normal enzymes. Herein we report the modeled structures of cellulolytic enzymes (endoglucanase, cellobiohydrolase and β-glucosidase) from a thermophilic bacterium, Clostridium thermocellum and their validation using Root Mean Square Deviation (RMSD) and Ramachandran plot analyses. Further, the molecular interactions of the modeled enzyme with cellulose were analyzed using molecular docking technique. The results of molecular docking showed that the endoglucanase, cellobiohydrolase and β-glucosidase had the binding affinities of -10.7, -9.0 and -10.8 kcal/mol, respectively. A correlation between the binding affinity of the endoglucanase with cellulose and the enzyme activity was also demonstrated. The results showed that the binding affinities of cellulases with cellulose could be used as a tool to assess the hydrolytic activity of cellulases. The results obtained could be used in virtual screening of cellulolytic enzymes based on the molecular interactions with the substrate, and aid in developing systems biology models of thermophiles for industrial biotechnology applications.

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Cohesin diversity revealed by the crystal structure of the anchoring cohesin from Ruminococcus flavefaciens

et al. 2009

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The cellulosome is an intriguing multienzyme complex found in cellulolytic bacteria that plays a key role in the degradation of plant cell-wall polysaccharides. In Ruminococcus flavefaciens, a predominant fiber-degrading bacterium found in ruminants, the cellulosome is anchored to the bacterial cell wall through a relatively short ScaE scaffoldin. Determination of the crystal structure of the lone type-III ScaE cohesin from R. flavefaciens (Rf-CohE) was initiated as a part of a structural effort to define cellulosome assembly. The structure was determined at 1.95 A resolution by single-wavelength anomalous diffraction. This is the first detailed description of a crystal structure for a type-III cohesin, and its features were compared with those of the known type-I and type-II cohesin structures. The Rf-CohE module folds into a nine-stranded beta-sandwich with jellyroll topology, typically observed for cohesins, and includes two beta-flaps in the midst of beta-strands 4 and 8, similar to the type-II cohesin structures. However, the presence in Rf-CohE of an additional 13-residue alpha-helix located between beta-strands 8 and 9 represents a dramatic divergence from other known cohesin structures. The prominent alpha-helix is enveloped by an extensive N-terminal loop, not observed in any other known cohesin, which embraces the helix presumably enhancing its stability. A planar surface at the upper portion of the front face of the molecule, bordered by beta-flap 8, exhibits plausible dimensions and exposed amino acid residues to accommodate the dockerin-binding site.

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Bacterial cellulases

Cited by 32 publications

References 1 publication

Unusual sequence organization in CenB, an inverting endoglucanase from Cellulomonas fimi

Unusual sequence organization in CenB, an inverting endoglucanase from Cellulomonas fimi

Bioprospecting of Thermostable Cellulolytic Enzymes through Modeling and Virtual Screening Method

Cohesin diversity revealed by the crystal structure of the anchoring cohesin from Ruminococcus flavefaciens

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