Putative catalytic NodB homology domain of PgaB, IcaB, and similar proteins which consist of a deformed (beta/alpha)8 barrel fold with 5- or 6-strands. 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 bacterial poly-beta-1,6-N-acetyl-D-glucosamine N-deacetylase PgaB, hemin storage system HmsF protein in gram-negative species, intercellular adhesion proteins IcaB, and many uncharacterized prokaryotic polysaccharide deacetylases. It also includes a putative polysaccharide deacetylase YxkH encoded by the Bacillus subtilis yxkH gene, which is one of six polysaccharide deacetylase gene homologs present in the Bacillus subtilis genome. Sequence comparison shows all family members contain a conserved domain similar to the catalytic NodB homology domain of rhizobial NodB-like proteins, which consists of a deformed (beta/alpha)8 barrel fold with 6 or 7 strands. However, in this family, most proteins have 5 strands and some have 6 strands. Moreover, long insertions are found in many family members, whose function remains unknown.

Putative catalytic NodB homology domain of a hypothetical protein Ecf1 from Escherichia coli and similar proteins. This family contains a hypothetical protein Ecf1 from Escherichia coli and its prokaryotic homologs. Although their biochemical properties remain to be determined, members in this family contain a conserved domain with a 5-stranded beta/alpha barrel, which is similar to the catalytic NodB homology domain of rhizobial NodB-like proteins, belonging to the larger carbohydrate esterase 4 (CE4) superfamily.

Putative catalytic polysaccharide deacetylase domain of uncharacterized protein yadE and similar proteins. This family contains an uncharacterized protein yadE from Escherichia coli and its bacterial homologs. Although its molecular function remains unknown, yadE shows high sequence similarity with the catalytic NodB homology domain of outer membrane lipoprotein PgaB and the surface-attached protein intercellular adhesion protein IcaB. Both PgaB and IcaB are essential in bacterial biofilm formation.

poly-beta-1,6-N-acetyl-D-glucosamine N-deacetylase PgaB. Two well-characterized systems produce polysaccharide based on N-acetyl-D-glucosamine in straight chains with beta-1,6 linkages. These are encoded by the icaADBC operon in Staphylococcus species, where the system is designated polysaccharide intercellular adhesin (PIA), and the pgaABCD operon in Gram-negative bacteria such as E. coli. Both systems include a putative polysaccharide deacetylase. The PgaB protein, described here, contains an additional domain lacking from its Gram-positive counterpart IcaB (TIGR03933). Deacetylation by this protein appears necessary to allow export through the porin PgaA [Cell envelope, Biosynthesis and degradation of surface polysaccharides and lipopolysaccharides]

Putative catalytic NodB homology domain of uncharacterized bacterial polysaccharide deacetylases which consist of a 5-stranded beta/alpha barrel. This family contains many uncharacterized bacterial polysaccharide deacetylases. Although their biological functions remain unknown, all members of the family are predicted to contain a conserved domain with a 5-stranded beta/alpha barrel, which is similar to the catalytic NodB homology domain of rhizobial NodB-like proteins, belonging to the larger carbohydrate esterase 4 (CE4) superfamily.

Structureof IcaB from Ammonifex degensii [Ammonifex degensii KC4]

Structureof BpsB deaceylase domain from Bordetella bronchiseptica [Bordetella bronchiseptica RB50],5BU6_B Structure of BpsB deaceylase domain from Bordetella bronchiseptica [Bordetella bronchiseptica RB50]

Escherichiacoli PgaB N-terminal domain [Escherichia coli K-12],3VUS_B Escherichia coli PgaB N-terminal domain [Escherichia coli K-12]

Structureof Escherichia coli PgaB 42-655 in complex with nickel [Escherichia coli K-12],4F9D_B Structure of Escherichia coli PgaB 42-655 in complex with nickel [Escherichia coli K-12]

Structureof Escherichia coli PgaB 42-655 in complex with iron [Escherichia coli K-12],4F9J_B Structure of Escherichia coli PgaB 42-655 in complex with iron [Escherichia coli K-12]

Putative polysaccharide deacetylase YxkH OS=Bacillus subtilis (strain 168) OX=224308 GN=yxkH PE=3 SV=1

Uncharacterized protein YadE OS=Escherichia coli (strain K12) OX=83333 GN=yadE PE=3 SV=2

Poly-beta-1,6-N-acetyl-D-glucosamine N-deacetylase OS=Escherichia coli O157:H7 OX=83334 GN=pgaB PE=3 SV=1

Poly-beta-1,6-N-acetyl-D-glucosamine N-deacetylase OS=Escherichia coli (strain K12) OX=83333 GN=pgaB PE=1 SV=1

Poly-beta-1,6-N-acetyl-D-glucosamine N-deacetylase OS=Staphylococcus aureus (strain MSSA476) OX=282459 GN=icaB PE=3 SV=1