Endohydrolysis of (1->4)-beta-D-xylosidic linkages in xylans. Optimum pH is 5.5-6. Optimum temperature is 102 degrees Celsius. Thermostable. The C-terminal CBM-CenC domains mediate the binding of XynA to microcrystalline cellulose. CBM-CenC 2 alone can also promote cellulose binding (By similarity). Belongs to the glycosyl hydrolase 10 (cellulase F) family.