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 5.4. Optimum temperature is 52 degrees Celsius. Glycan degradation; xylan degradation. Expressed in the presence of D-xylose under conditions of alkaline ambient pH, probably under the regulation of the pacC transcription factor. Repressed in presence of glucose through the action of the creA transcription repressor. An increase in fruity aroma was organoleptically detected in the wine produced by the recombinant wine yeast strain T73 expressing xnlA. Belongs to the glycosyl hydrolase 11 (cellulase G) family.