polysaccharide deacetylase family sporulation protein PdaB. This model describes the YbaN protein family, also called PdaB and SpoVIE, of Gram-positive bacteria. Although ybaN null mutants have only a mild sporulation defect, ybaN/ytrI double mutants show drastically reducted sporulation efficiencies. This synthetic defect suggests the role of this sigmaE-controlled gene in sporulation had been masked by functional redundancy. Members of this family are homologous to a characterized polysaccharide deacetylase; the exact function this protein family is unknown. [Cellular processes, Sporulation and germination]

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.

Putative catalytic NodB homology domain of Bacillus subtilis putative polysaccharide deacetylase PdaB, 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 the putative polysaccharide deacetylase PdaB encoded by the pdaB gene on sporulation of Bacillus subtilis. Although its biochemical properties remain to be determined, the PdaB (YbaN) protein is essential for maintaining spores after the late stage of sporulation and is highly conserved in spore-forming bacteria. The glycans of the spore cortex may be candidate PdaB substrates. Based on sequence similarity, the family members are classified as carbohydrate esterase 4 (CE4) superfamily members. However, the classical His-His-Asp zinc-binding motif of CE4 esterases is missing in this family.

Putative catalytic domain of rhizobial NodB chitooligosaccharide N-deacetylase and its bacterial homologs. This family corresponds to rhizobial NodB chitooligosaccharide N-deacetylase (EC 3.5.1.-), encoded by nodB gene from the nodulation (nod) gene cluster that is responsible for the biosynthesis of bacterial nodulation signals, termed Nod factors. NodB is involved in de-N-acetylating the nonreducing N-acetylglucosamine residue of chitooligosaccharides to allow for the attachment of the fatty acyl group by the acyltransferase NodA. The monosaccharide N-acetylglucosamine cannot be deacetylated by NodB. NodB is composed of a 6-stranded barrel catalytic domain with detectable sequence similarity to the 7-stranded barrel homology domain of polysaccharide deacetylase (DCA)-like proteins in the larger carbohydrate esterase 4 (CE4) superfamily.

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

Structureof Streptococcus pneumoniae peptidoglycan deacetylase (SpPgdA) [Streptococcus pneumoniae R6]

T48deacetylase [Arthrobacter sp. AW19M34-1],5LGC_A T48 deacetylase with substrate [Arthrobacter sp. AW19M34-1]

Structureof Streptococcus pneumoniae peptidoglycan deacetylase (SpPgdA) D 275 N Mutant. [Streptococcus pneumoniae R6]

Structureof a family 4 carbohydrate esterase from Bacillus anthracis [Bacillus anthracis str. Ames]

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

Peptidoglycan-N-acetylglucosamine deacetylase BC_3618 OS=Bacillus cereus (strain ATCC 14579 / DSM 31 / CCUG 7414 / JCM 2152 / NBRC 15305 / NCIMB 9373 / NCTC 2599 / NRRL B-3711) OX=226900 GN=BC_3618 PE=1 SV=1

Chitooligosaccharide deacetylase OS=Sinorhizobium fredii (strain NBRC 101917 / NGR234) OX=394 GN=nodB PE=3 SV=2

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

Chitooligosaccharide deacetylase OS=Bradyrhizobium elkanii OX=29448 GN=nodB PE=3 SV=1