Endo-1,4-beta-xylanase involved in the hydrolysis of xylan, a major structural heterogeneous polysaccharide found in plant biomass representing the second most abundant polysaccharide in the biosphere, after cellulose. Accounts for approximately 70 percent of the endoxylanase activity in the culture filtrate (By similarity). Endohydrolysis of (1->4)-beta-D-xylosidic linkages in xylans. Glycan degradation; xylan degradation. Belongs to the glycosyl hydrolase 10 (cellulase F) family.