Chitinases (EC 126.96.36.199)  are enzymes that catalyze the hydrolysis of the
β-1,4-N-acetyl-D-glucosamine linkages in chitin polymers. From the view
point of sequence similarity chitinases belong to either family 18 or 19 in
the classification of glycosyl hydrolases [2,E1]. Chitinases of family 18
(also known as classes III or V) groups a variety of proteins:
a) Chitinases from:
- Prokaryotes such as Alteromonas, Bacillus, Serratia, Streptomyces, etc.
- Plants such as Arabidopsis, cucumber, bean, tobacco, etc.
- Fungi such as Aphanocladium, Rhizopus, Saccharomyces, etc.
- Nematode (Brugia malayi).
- Insects (Manduca sexta).
- Baculoviruses (Autographa Californica Nuclear Polyhedrosis virus).
b) Other proteins:
- Hevamine, a rubber tree protein with chitinase and lysozyme activities.
- Kluyveromyces lactis killer toxin alpha subunit, which acts as a chitinase.
- Flavobacterium and Streptomyces endo-beta-N-acetylglucosaminidases (EC 3.2.
- Mammalian di-N-acetylchitobiase which is involved in the degradation of
- Human cartilage glycoprotein Gp-39.
- Jack bean concanavalin B (conB), a protein that has lost its catalytic
Site directed mutagenesis experiments  and crystallographic data [4,5] have
shown that a conserved glutamate is involved in the catalytic mechanism and
probably acts as a proton donor. This glutamate is at the extremity of the
best conserved region in these proteins.
PROSITE is copyrighted by the SIB Swiss Institute of Bioinformatics and
distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives
(CC BY-NC-ND 4.0) License, see prosite_license.html.