Abstract
Many chitinases and their genes have been obtained from various plants. To understand structural features of plant chitinases, some classification systems have been proposed by some research groups. However, the complicated multiple classification of plant chitinases frequently confuses researchers. In this article, structures and classification systems of plant chitinases are reviewed, and their issues are discussed. Plant chitinase is considered to protect plants against fungal pathogens by degrading chitin, a major component of the cell walls of many fungi. The antifungal activity of various chitinases derived from various plant sources has been investigated, but a correlation between the structure and the antifungal activity of the proteins has been unclear. To exhibit antifungal activity, a chitinase must bind to fungal cell walls, and then, it should degrade the chitin in them. Roles of the chitin-binding domain and catalytic domain in antifungal activity of plant chitinases are discussed.
