PROSITE documentation PDOC00507
Glycosyl hydrolases family 17 signature


It has been shown [1,2] that the following glycosyl hydrolases can be classified into a single family on the basis of sequence similarities:

  • Glucan endo-1,3-β-D-glucosidases (EC (endo-(1->3)-β- glucanase) from various plants. This enzyme may be involved in the defense of plants against pathogens through its ability to degrade fungal cell wall polysaccharides.
  • Glucan 1,3-β-glucosidase (EC (exo-(1->3)-β-glucanase) from yeast (gene BGL2). This enzyme may play a role in cell expansion during growth, in cell-cell fusion during mating, and in spore release during sporulation.
  • Lichenases (EC (endo-(1->3,1->4)-β-glucanase) from various plants.

The best conserved region in the sequence of these enzymes is located in their central section. This region contains a conserved tryptophan residue which could be involved in the interaction with the glucan substrates [2] and it also contains a conserved glutamate which has been shown [3] to act as the nucleophile in the catalytic mechanism. We have used this region as a signature pattern.

Expert(s) to contact by email:

Henrissat B.

Last update:

December 2004 / Pattern and text revised.


Technical section

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

GLYCOSYL_HYDROL_F17, PS00587; Glycosyl hydrolases family 17 signature  (PATTERN)


1AuthorsHenrissat B.
TitleA classification of glycosyl hydrolases based on amino acid sequence similarities.
SourceBiochem. J. 280:309-316(1991).
PubMed ID1747104

2AuthorsOri N. Sessa G. Lotan T. Himmelhoch S. Fluhr R.
TitleA major stylar matrix polypeptide (sp41) is a member of the pathogenesis-related proteins superclass.
SourceEMBO J. 9:3429-3436(1990).
PubMed ID2120041

3AuthorsVarghese J.N. Garrett T.P.J. Colman P.M. Chen L. Hoj P.B. Fincher G.B.
TitleThree-dimensional structures of two plant beta-glucan endohydrolases with distinct substrate specificities.
SourceProc. Natl. Acad. Sci. U.S.A. 91:2785-2789(1994).
PubMed ID8146192

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