Contains two catalytic domains with xylanase and endo-beta-1,3-1,4 glucanase activities. Endohydrolysis of (1->4)-beta-D-xylosidic linkages in xylans. Hydrolysis of (1->4)-beta-D-glucosidic linkages in beta-D-glucans containing (1->3)- and (1->4)-bonds. Glycan degradation; xylan degradation. In the N-terminal section; belongs to the glycosyl hydrolase 11 (cellulase G) family. In the C-terminal section; belongs to the glycosyl hydrolase 16 family.