Glycosyl hydrolase family 9.

Cellulase N-terminal ig-like domain.

N-terminal Early set domain associated with the catalytic domain of cellulase. E or "early" set domains are associated with the catalytic domain of cellulases at the N-terminal end. Cellulases are O-glycosyl hydrolases (GHs) that hydrolyze beta 1-4 glucosidic bonds in cellulose. They are usually categorized into either exoglucanases, which sequentially release terminal sugar units from the cellulose chain, or endoglucanases, which also attack the chain internally. The N-terminal domain of cellulase may be related to the immunoglobulin and/or fibronectin type III superfamilies. These domains are associated with different types of catalytic domains at either the N-terminal or C-terminal end and may be involved in homodimeric/tetrameric/dodecameric interactions. Members of this family include members of the alpha amylase family, sialidase, galactose oxidase, cellulase, cellulose, hyaluronate lyase, chitobiase, and chitinase, among others.

Catalytic NodB homology domain of Bacillus subtilis polysaccharide deacetylase PdaA, and its bacterial homologs. The Bacillus subtilis genome contains six polysaccharide deacetylase gene homologs: pdaA, pdaB (previously known as ybaN), yheN, yjeA, yxkH and ylxY. This family is represented by Bacillus subtilis pdaA gene encoding polysaccharide deacetylase BsPdaA, which is a member of the carbohydrate esterase 4 (CE4) superfamily. BsPdaA deacetylates peptidoglycan N-acetylmuramic acid (MurNAc) residues to facilitate the formation of muramic delta-lactam, which is required for recognition of germination lytic enzymes. BsPdaA deficiency leads to the absence of muramic delta-lactam residues in the spore cortex. Like other CE4 esterases, BsPdaA consists of a single catalytic NodB homology domain that appears to adopt a deformed (beta/alpha)8 barrel fold with a putative substrate binding groove harboring the majority of the conserved residues. It utilizes a general acid/base catalytic mechanism involving a tetrahedral transition intermediate, where a water molecule functions as the nucleophile tightly associated to the zinc cofactor.

Catalytic NodB homology domain of rhizobial NodB-like proteins. This family belongs to the large and functionally diverse carbohydrate esterase 4 (CE4) superfamily, whose members show strong sequence similarity with some variability due to their distinct carbohydrate substrates. It includes many rhizobial NodB chitooligosaccharide N-deacetylase (EC 3.5.1.-)-like proteins, mainly from bacteria and eukaryotes, such as chitin deacetylases (EC 3.5.1.41), bacterial peptidoglycan N-acetylglucosamine deacetylases (EC 3.5.1.-), and acetylxylan esterases (EC 3.1.1.72), which catalyze the N- or O-deacetylation of substrates such as acetylated chitin, peptidoglycan, and acetylated xylan. All members of this family contain a catalytic NodB homology domain with the same overall topology and a deformed (beta/alpha)8 barrel fold with 6- or 7 strands. Their catalytic activity is dependent on the presence of a divalent cation, preferably cobalt or zinc, and they employ a conserved His-His-Asp zinc-binding triad closely associated with the conserved catalytic base (aspartic acid) and acid (histidine) to carry out acid/base catalysis. Several family members show diversity both in metal ion specificities and in the residues that coordinate the metal.

Crystalstructure of metagenome-derived glycoside hydrolase family 9 endoglucanase [uncultured bacterium],3X17_B Crystal structure of metagenome-derived glycoside hydrolase family 9 endoglucanase [uncultured bacterium]

Crystalstructure of Zn-binding triple mutant of GH family 9 endoglucanase J30 [Thermobacillus composti KWC4]

Crystalstructure of GH family 9 endoglucanase J30 [Thermobacillus composti KWC4]

Bacteroidesovatus GH9 Bacova_02649 [Bacteroides ovatus ATCC 8483]

ChainA, CELLULOSE 1,4-BETA-CELLOBIOSIDASE [Acetivibrio thermocellus]

Endoglucanase C OS=Cellulomonas fimi (strain ATCC 484 / DSM 20113 / JCM 1341 / NBRC 15513 / NCIMB 8980 / NCTC 7547) OX=590998 GN=cenC PE=1 SV=2

Xyloglucan-specific endo-beta-1,4-glucanase BoGH9A OS=Bacteroides ovatus (strain ATCC 8483 / DSM 1896 / JCM 5824 / BCRC 10623 / CCUG 4943 / NCTC 11153) OX=411476 GN=BACOVA_02649 PE=1 SV=1

Cellodextrinase OS=Butyrivibrio fibrisolvens OX=831 GN=ced1 PE=1 SV=1

Cellulase 1 OS=Streptomyces reticuli OX=1926 GN=cel1 PE=1 SV=1

Endoglucanase A OS=Cellvibrio japonicus (strain Ueda107) OX=498211 GN=celA PE=3 SV=2