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.