Chitinase from T. kodakarensis (TkChiA) catalyzes the hydrolysis of chitin. The enzyme consists of two catalytic and three binding domains (ChBD1, ChBD2 and ChBD3). ChBD2 and ChBD3 can bind to not only chitin but also cellulose. In both domains, the intervals of the side chains of the three tryptophan residues, which are located on the molecular surface, correspond to twice the length of the lattice of the chitin. A binding model with crystalline chitin implies that the tryptophan residues and a glutamate residue interact with the hexose ring by CH-π interactions and the amide group by a hydrogen bond, respectively.
Keywords: CH-π interaction; X-ray analysis; chitinase from Thermococcus kodakarensis; circular dichroism spectroscopy; crystalline chitin.
© 2016 Federation of European Biochemical Societies.