This family includes the PgaD protein from E. coli. The homopolymer poly-beta-1,6-N-acetyl-D-glucosamine (beta-1,6-GlcNAc; PGA) serves as an adhesin for the maintenance of biofilm structural stability in eubacteria. The pgaABCD operon is required for its synthesis and export. It has been shown that PgaD is essential for this process.
Jiyao W et al.(2023). "The conserved domain database in 2023.",