{PDOC00507} {PS00587; GLYCOSYL_HYDROL_F17} {BEGIN} ******************************************* * 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-beta-D-glucosidases (EC 3.2.1.39) (endo-(1->3)-beta- 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-beta-glucosidase (EC 3.2.1.58) (exo-(1->3)-beta-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 3.2.1.73) (endo-(1->3,1->4)-beta-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. -Consensus pattern: [LIVMKS]-x-[LIVMFYWA](3)-[STAG]-E-[STACVI]-G-[WY]-P-[STN]- x-[SAGQ] [E is an active site residue] -Sequences known to belong to this class detected by the pattern: ALL. -Other sequence(s) detected in Swiss-Prot: NONE. -Expert(s) to contact by email: Henrissat B.; bernie@afmb.cnrs-mrs.fr -Last update: December 2004 / Pattern and text revised. [ 1] Henrissat B. "A classification of glycosyl hydrolases based on amino acid sequence similarities." Biochem. J. 280:309-316(1991). PubMed=1747104 [ 2] Ori N., Sessa G., Lotan T., Himmelhoch S., Fluhr R. "A major stylar matrix polypeptide (sp41) is a member of the pathogenesis-related proteins superclass." EMBO J. 9:3429-3436(1990). PubMed=2120041 [ 3] Varghese J.N., Garrett T.P.J., Colman P.M., Chen L., Hoj P.B., Fincher G.B. "Three-dimensional structures of two plant beta-glucan endohydrolases with distinct substrate specificities." Proc. Natl. Acad. Sci. U.S.A. 91:2785-2789(1994). PubMed=8146192 -------------------------------------------------------------------------------- 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 https://prosite.expasy.org/prosite_license.html -------------------------------------------------------------------------------- {END}