Acetylxylan esterase 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. Degrades acetylated xylans by cleaving acetyl side groups from the hetero-xylan backbone. Deacetylation of xylans and xylo-oligosaccharides. Inactivated by phenylmethylsulfonylfluorid (PMSF), a specific inhibitor of serine esterases. Optimum pH is 5.3. Optimum temperature is 50 degrees Celsius. Glycan degradation; xylan degradation. Monomer. Has a modular structure: a carbohydrate esterase catalytic module at the N-terminus, a linker rich in serines and threonines, and a C-terminal carbohydrate-binding module (CBM). The genes for catalytic modules and CBMs seem to have evolved separately and have been linked by gene fusion. Glycosylated. The promoter contains 1 xlnR-binding sequence (a transcriptional activator in the absence of glucose), 5 creA-binding sequences (a negatively acting regulatory protein mediating carbon catabolyte repression), 1 pacC-binding sequence (a pH regulator), 3 alcR-binding sequences (an activator of alcohol and acetaldehyde dehydrogenase genes) and 3 areA-binding sequences (a nitrogen metabolism activator). Belongs to the carbohydrate esterase 1 (CE1) family. AxeA subfamily.