This conserved domain family includes xylanase inhibitor Xip-I, and the class III plant chitinases such as hevamine, concanavalin B, and PPL2, all of which have a glycosyl hydrolase family 18 (GH18) domain. Hevamine is a class III endochitinase that hydrolyzes the linear polysaccharide chains of chitin and peptidoglycan and is important for defense against pathogenic bacteria and fungi. PPL2 (Parkia platycephala lectin 2) is a class III chitinase from Parkia platycephala seeds that hydrolyzes beta(1-4) glycosidic bonds linking 2-acetoamido-2-deoxy-beta-D-glucopyranose units in chitin.
Jiyao W et al.(2023). "The conserved domain database in 2023.",