PROSITE documentation PDOC00620
Chitinases family 19 signatures


Chitinases (EC [1] 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 19 (also known as classes IA or I and IB or II) are enzymes from plants that function in the defense against fungal and insect pathogens by destroying their chitin-containing cell wall. Class IA/I and IB/II enzymes differ in the presence (IA/I) or absence (IB/II) of a N-terminal chitin-binding domain (see the relevant entry <PDOC00025>). The catalytic domain of these enzymes consist of about 220 to 230 amino acid residues.

As signature patterns we selected two highly conserved regions, the first one is located in the N-terminal section and contains one of the six cysteines which are conserved in most, if not all, of these chitinases and which is probably involved in a disulfide bond.

Expert(s) to contact by email:

Neuhaus J.-M.
Henrissat B.

Last update:

November 1997 / Text revised.


Technical section

PROSITE methods (with tools and information) covered by this documentation:

CHITINASE_19_1, PS00773; Chitinases family 19 signature 1  (PATTERN)

CHITINASE_19_2, PS00774; Chitinases family 19 signature 2  (PATTERN)


1AuthorsFlach J. Pilet P.-E. Jolles P.
TitleWhat's new in chitinase research?
SourceExperientia 48:701-716(1992).
PubMed ID1516675

2AuthorsHenrissat B.
TitleA classification of glycosyl hydrolases based on amino acid sequence similarities.
SourceBiochem. J. 280:309-316(1991).
PubMed ID1747104


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