Structural determinants of the substrate specificities of xylanases from different glycoside hydrolase families.
Xylanases are of widespread importance in several food and non-food biotechnological applications. They degrade heteroxylans, a structurally heterogeneous group of plant cell wall polysaccharides, and other important components in various industrial processes. Because of the highly complex structures of heteroxylans, efficient utilization of xylanases in these processes requires an in-depth knowledge of their substrate specificity. A significant number of studies on the three-dimensional structures of xylanases from different glycoside hydrolase (GH) families in complex with the substrate provided insight into the different mechanisms and strategies by which xylanases bind and hydrolyze structurally different heteroxylans and xylo-oligosaccharides (XOS). Combined with reports on the hydrolytic activities of xylanases on decorated XOS and heteroxylans, major advances have been made in our understanding of the link between the three-dimensional structures and the substrate specificities of these enzymes. In this review, authors gave a concise overview of the structure-function relationship of xylanases from GH5, 8, 10, and 11. The structural basis for inter- and intrafamily variation in xylanase substrate specificity was discussed as are the implications for heteroxylan degradation.
Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Centre, Katholieke Universiteit Leuven, Leuven, Belgium.
Annick
A
Pollet
Jan A
JA
Delcour
Christophe M
CM
Courtin
D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D043364:Endo-1,4-beta Xylanases / Q000737:chemistry* / Q000378:metabolism*; D008958:Models, Molecular; D009844:Oligosaccharides / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D013329:Structure-Activity Relationship; D013379:Substrate Specificity; D014990:Xylans / Q000737:chemistry* / Q000378:metabolism*
D001426:Bacterial Proteins; D009844:Oligosaccharides; D014990:Xylans; D043364:Endo-1,4-beta Xylanases