First crystal structure of an endo-inulinase, INU2, from Aspergillus ficuum: Discovery of an extra-pocket in the catalytic domain responsible for its endo-activity

► The first crystal structure of an endo-inulinase (from A. Ficuum) was determined. ► Its fructosyl complex points an extra pocket in the catalytic site. ► This cavity not present in exo-enzymes would explain the endo-activity of the enzyme. ► Molecular modelling supports endo-cleavage at the third fructose of the substrate.