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.

Catalytic NodB homology domain of uncharacterized bacterial polysaccharide deacetylases. This family includes many uncharacterized bacterial polysaccharide deacetylases. Although their biological function still remains unknown, members in this family show high sequence homology to the catalytic NodB homology domain of Streptococcus pneumoniae polysaccharide deacetylase PgdA (SpPgdA), which is an extracellular metal-dependent polysaccharide deacetylase with de-N-acetylase activity toward a hexamer of chitooligosaccharide N-acetylglucosamine, but not shorter chitooligosaccharides or a synthetic peptidoglycan tetrasaccharide. Like SpPgdA, this family is a member of the carbohydrate esterase 4 (CE4) superfamily.

Polysaccharide deacetylase. This domain is found in polysaccharide deacetylase. This family of polysaccharide deacetylases includes NodB (nodulation protein B from Rhizobium) which is a chitooligosaccharide deacetylase. It also includes chitin deacetylase from yeast, and endoxylanases which hydrolyzes glucosidic bonds in xylan.

Catalytic NodB homology domain of Clostridium thermocellum acetylxylan esterase and its bacterial homologs. This family is represented by Clostridium thermocellum acetylxylan esterase (CtAXE, EC 3.1.1.72), a member of the carbohydrate esterase 4 (CE4) superfamily. CtAXE deacetylates O-acetylated xylan, a key component of plant cell walls. It shows no detectable activity on generic esterase substrates including para-nitrophenyl acetate. It is specific for sugar-based substrates and will precipitate acetylxylan, as a consequence of deacetylation. CtAXE is a monomeric protein containing a catalytic NodB homology domain with the same overall topology and a deformed (beta/alpha)8 barrel fold as other CE4 esterases. However, due to differences in the topography of the substrate-binding groove, the chemistry of the active center, and metal ion coordination, CtAXE has different metal ion preference and lacks activity on N-acetyl substrates. It is significantly activated by Co2+. Moreover, CtAXE displays distinctly different ligand coordination to the metal ion, utilizing an aspartate, a histidine, and four water molecules, as opposed to the conserved His-His-Asp zinc-binding triad of other CE4 esterases.

Peptidoglycan/xylan/chitin deacetylase, PgdA/CDA1 family [Carbohydrate transport and metabolism, Cell wall/membrane/envelope biogenesis].

ChainA, Predicted xylanase/chitin deacetylase [Caldanaerobacter subterraneus subsp. tengcongensis MB4]

Crystalstructure of a BA3943 mutant,a CE4 family pseudoenzyme with restored enzymatic activity. [Bacillus anthracis]

ChainA, CHITIN DEACETYLASE [Aspergillus nidulans],2Y8U_B Chain B, CHITIN DEACETYLASE [Aspergillus nidulans]

Crystalstructure of the Bc1960 peptidoglycan N-acetylglucosamine deacetylase in complex with 4-naphthalen-1-yl-~{N}-oxidanyl-benzamide [Bacillus cereus ATCC 14579],5O6Y_C Crystal structure of the Bc1960 peptidoglycan N-acetylglucosamine deacetylase in complex with 4-naphthalen-1-yl-~{N}-oxidanyl-benzamide [Bacillus cereus ATCC 14579],5O6Y_D Crystal structure of the Bc1960 peptidoglycan N-acetylglucosamine deacetylase in complex with 4-naphthalen-1-yl-~{N}-oxidanyl-benzamide [Bacillus cereus ATCC 14579]

Crystalstructure of the Bc1960 peptidoglycan N-acetylglucosamine deacetylase in complex with 4-naphthalen-1-yl-~{N}-oxidanyl-benzamide [Bacillus cereus ATCC 14579]

Chitooligosaccharide deacetylase OS=Rhizobium meliloti (strain 1021) OX=266834 GN=nodB PE=3 SV=3

Chitooligosaccharide deacetylase OS=Mesorhizobium japonicum (strain LMG 29417 / CECT 9101 / MAFF 303099) OX=266835 GN=nodB PE=3 SV=2

Chitooligosaccharide deacetylase OS=Azorhizobium caulinodans (strain ATCC 43989 / DSM 5975 / JCM 20966 / LMG 6465 / NBRC 14845 / NCIMB 13405 / ORS 571) OX=438753 GN=nodB PE=3 SV=2

Chitooligosaccharide deacetylase OS=Rhizobium leguminosarum bv. viciae OX=387 GN=nodB PE=3 SV=1

Chitooligosaccharide deacetylase OS=Bradyrhizobium sp. (strain ANU 289) OX=186901 GN=nodB PE=3 SV=2