PF-ChiA is an uncharacterized chitinase found in the hyperthermophilic archaeon Pyrococcus furiosus with a glycosyl hydrolase family 18 (GH18) catalytic domain as well as a cellulose-binding domain. Members of this domain family are found not only in archaea but also in eukaryotes and prokaryotes. PF-ChiA exhibits hydrolytic activity toward both colloidal and crystalline (beta/alpha) chitins at high temperature.