{PDOC60000} {PS60000; CHITOSANASE_46_80} {BEGIN} ********************************************************** * Chitosanases families 46 and 80 active sites signature * ********************************************************** Chitosanases (EC 3.2.1.132) are enzymes that catalyze the hydrolysis of chitosan, but not chitin. They are defined as carbohydrolases that hydrolyze partially N-acetylated chitosan, splitting the beta-1,4-glycosidic linkages except the N-acetyl-glucosamine homo-linkages (GlcNAc-GlcNAc) [1]. From the view point of sequence and folding similarities chitosanases belong to families 46, 75 or 80 in the classification of glycosyl hydrolases [2,E1]. Chitosanases of families 46 and 80 are enzymes from bacteria and Chlorella viruses that share a conserved active site-related module [3]. This module includes several amino acids essential for enzyme activity and (or) stability as shown by site-directed mutagenesis studies. -Consensus pattern: E-[DNQ]-x(8,17)-Y-x(7)-D-x-[RD]-[GP]-x-[TS]-x(3)-[AIVFLY]- G-x(5,11)-D [The E and first D are active site residues] -Sequences known to belong to this class detected by the pattern: ALL. -Other sequence(s) detected in Swiss-Prot: NONE. -Last update: May 2004 / Text revised. [ 1] Fukamizo T., Brzezinski R. "Chitosanase from Streptomyces sp. strain N174: a comparative review of its structure and function." Biochem. Cell Biol. 75:687-696(1997). PubMed=9599657 [ 2] Henrissat B., Bairoch A. "Updating the sequence-based classification of glycosyl hydrolases." Biochem. J. 316:695-696(1996). PubMed=8687420 [ 3] Tremblay H., Blanchard J., Brzezinski R. "A common molecular signature unifies the chitosanases belonging to families 46 and 80 of glycoside hydrolases." Can. J. Microbiol. 46:952-955(2000). PubMed=11068683 [E1] http://www.cazy.org/Glycoside-Hydrolases.html -------------------------------------------------------------------------------- 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}