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. Endohydrolysis of (1->4)-beta-D-xylosidic linkages in xylans. Metal ions, copper, iron and N-bromosuccinimide decrease enzyme activity. Manganese, calcium, L-tryptophan, beta-mercaptoethanol, L-cysteine and dithiodipyridine stimulate the enzyme activity. Optimum pH is 5.0. Retains about 76 percent of its activity after being incubated at pH 2.0 for 30 min at 37 degrees Celsius. Optimum temperature is 50 degrees Celsius. Displays about 95 percent of peak activity in the temperature range from 37 to 41 degrees Celsius. Glycan degradation; xylan degradation. Belongs to the glycosyl hydrolase 11 (cellulase G) family.