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From 2011.igem.org

DspB has been isolated and purified and has been shown to increase dissemination of wild type cells from biofilm and restore dissemination in mutant cells.

DspB is most likely an N-acetylglucosaminidase that causes the detachment of cells from biofilm colonies through the 1→ 4 glycosidic bond of β-substituted N-acetylglucosamine (Kaplan 2003). DspB is homologous to family 20 glycosyl hydrolases which cleave terminal monosaccharide residues (Kaplan 2003).

One possible substrate for dspB is a type IV pilus required for the attachment and autoaggregation of bacteria by altering its adhesive properties. Another possible substrate is exopolysaccharide which is part of the exopolysaccharide matrix which plays a role in biofilm formation. Exopolysaccharides may contain N-acetylglucosamine which dspB is thought to hydrolyze. Manuel et al have characterized the mechanistic aspects of dspB and show that conserved D183 and E184 resemble the proposed 20 β-hexosaminidase mechanism; that aromatic residues W237, Y278 and D183 assist N-acetal group orientation and hydrolysis; that Y187 plays a role in specificity; and that residues R27, E332 and W330 help stabilize the transition state of hydrolysis.

Although studies on dspB have used Actinobacillus actinomycetemcomitans as a study subject, the fact that