Figure 5.

Schematic presentation of the mode of TlXyn30A action on glucuronoxylan. Initially, the polysaccharide is converted to a mixture of aldouronic acids of a general structure MeGlcA²Xyl_n. Later, the unsubstituted regions are also attacked by the enzyme, yielding aldotriouronic acid MeGlcA²Xyl₂ and Xyl₂ as major products (in solid boxes) that are accompanied with small amounts of aldotetraouronic acid MeGlcA²Xyl₃, Xyl, and Xyl₃ (dashed boxes) as limit hydrolysis products.