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. Optimum pH is 6.0. Retains over 95 percent activity in the pH range from 5.0 to 7.0, and 70 percent activity in the pH range from 4.0 to 8.0. Optimum temperature is 58 degrees Celsius. Has complete stability at 60 degrees Celsius. Glycan degradation; xylan degradation. The promoter contains two 5'-GGCTAAA-3' sequences identified as binding sites for the xylanolytic transcriptional activator xlnR. Belongs to the glycosyl hydrolase 11 (cellulase G) family.