ALGX is a family found in bacteria. The domain demonstrates catalytic activity similar to that of the SGNH hydrolase-like domain, with the typical Ser-His-Asp triad found in this enzyme. Alginate is an exopolysaccharide that contributes to biofilm formation. ALGX is secreted into the biofilm and is responsible for the acetylation of biofilm polymers that help protect them from host destruction [1].

1: Structural and functional characterization of Pseudomonas aeruginosa AlgX: role of AlgX in alginate acetylation. Riley LM, Weadge JT, Baker P, Robinson H, Codee JD, Tipton PA, Ohman DE, Howell PL; J Biol Chem. 2013;288:22299-22314. PMID:23779107