Major xylan-degrading enzyme. Contributes to the hydrolysis of arabinoxylan, the major component of maize cell-walls. Endohydrolysis of (1->4)-beta-D-xylosidic linkages in xylans. Glycan degradation; xylan degradation. The N-terminus is blocked. Belongs to the glycosyl hydrolase 11 (cellulase G) family.