Insights into exo- and endoglucanase activities of family 6 glycoside hydrolases from Podospora anserina - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Applied and Environmental Microbiology Année : 2013

Insights into exo- and endoglucanase activities of family 6 glycoside hydrolases from Podospora anserina

Résumé

The ascomycete Podospora anserina is a coprophilous fungus that grows at late stages on droppings of herbivores. Its genome encodes a large diversity of carbohydrate-active enzymes. Among them, four genes encode glycoside hydrolases from family 6 (GH6), the members of which comprise putative endoglucanases and exoglucanases, some of them exerting important functions for biomass degradation in fungi. Therefore, this family was selected for functional analysis. Three of the enzymes, P. anserina Cel6A (PaCel6A), PaCel6B, and PaCel6C, were functionally expressed in the yeast Pichia pastoris. All three GH6 enzymes hydrolyzed crystalline and amorphous cellulose but were inactive on hydroxyethyl cellulose, mannan, galactomannan, xyloglucan, arabinoxylan, arabinan, xylan, and pectin. PaCel6A had a catalytic efficiency on cellotetraose comparable to that of Trichoderma reesei Cel6A (TrCel6A), but PaCel6B and PaCel6C were clearly less efficient. PaCel6A was the enzyme with the highest stability at 45°C, while PaCel6C was the least stable enzyme, losing more than 50% of its activity after incubation at temperatures above 30°C for 24 h. In contrast to TrCel6A, all three studied P. anserina GH6 cellulases were stable over a wide range of pHs and conserved high activity at pH values of up to 9. Each enzyme displayed a distinct substrate and product profile, highlighting different modes of action, with PaCel6A being the enzyme most similar to TrCel6A. PaCel6B was the only enzyme with higher specific activity on carboxymethylcellulose (CMC) than on Avicel and showed lower processivity than the others. Structural modeling predicts an open catalytic cleft, suggesting that PaCel6B is an endoglucanase.
Fichier principal
Vignette du fichier
Laetitia Poidevin et al 2013_1.pdf (1.51 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)
Loading...

Dates et versions

hal-01268147 , version 1 (29-05-2020)

Identifiants

Citer

Laetitia Poidevin, Julia Feliu, Annick Doan, Jean-Guy Berrin, Mathieu Bey, et al.. Insights into exo- and endoglucanase activities of family 6 glycoside hydrolases from Podospora anserina. Applied and Environmental Microbiology, 2013, 79 (14), pp.4220-4229. ⟨10.1128/AEM.00327-13⟩. ⟨hal-01268147⟩
109 Consultations
36 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More