β-xylosidases and α-L-arabinofuranosidases: accessory enzymes for arabinoxylan degradation.
Arabinoxylan (AX) is among the most abundant hemicelluloses on earth and one of the major components of feedstocks that are currently investigated as a source for advanced biofuels. As global research into these sustainable biofuels is increasing, scientific knowledge about the enzymatic breakdown of AX advanced significantly over the last decade. This review focuses on the exo-acting AX hydrolases, such as α-arabinofuranosidases and β-xylosidases. It aims to provide a comprehensive overview of the diverse substrate specificities and corresponding structural features found in the different glycoside hydrolase families. A careful review of the available literature reveals a marked difference in activity between synthetically labeled and naturally occurring substrates, often leading to erroneous enzymatic annotations. Therefore, special attention is given to enzymes with experimental evidence on the hydrolysis of natural polymers.
Division of Gene Technology, KU Leuven, Kasteelpark Arenberg 21-box 2462, 3001 Leuven, Belgium.
Stijn
S
Lagaert
Laboratory of Food Chemistry and Biochemistry & Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, Kasteelpark Arenberg 20-box 2463, 3001 Leuven, Belgium.
Annick
A
Pollet
Laboratory of Food Chemistry and Biochemistry & Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, Kasteelpark Arenberg 20-box 2463, 3001 Leuven, Belgium. Electronic address: Christophe.Courtin@biw.kuleuven.be.
Christophe M
CM
Courtin
Division of Gene Technology, KU Leuven, Kasteelpark Arenberg 21-box 2462, 3001 Leuven, Belgium.
Guido
G
Volckaert
D001426:Bacterial Proteins; D018533:Biomass; D006026:Glycoside Hydrolases; D010940:Plant Proteins; D014990:Xylans / Q000378:metabolism*; D014995:Xylosidases
D001426:Bacterial Proteins; D010940:Plant Proteins; D014990:Xylans; C085118:arabinoxylan; D006026:Glycoside Hydrolases; D014995:Xylosidases; C026579:exo-1,4-beta-D-xylosidase; C019713:alpha-N-arabinofuranosidase
Biomass; Glycoside hydrolases; Hemicellulases; Hemicellulose; Polysaccharide degradation; Xylanolytic enzymes