SI-CLP is a novel member of Glyco_18 domain–containing human chitinases and chitinase-like proteins. (A) Schematic representation of domain organization of mammalian Glyco_18 domain–containing protein. (B) Critical amino acid in catalytic sites. The characteristic FDG sequence preceding catalytic motif is shown in shaded column. Catalytic amino acids are shown in bold. Complete active catalytic motifs are underlined.