poly-beta-1,6 N-acetyl-D-glucosamine export porin PgaA
Members of this protein family are the poly-beta-1,6 N-acetyl-D-glucosamine (PGA) export porin PgaA of Gram-negative bacteria. There is no counterpart in the poly-beta-1,6 N-acetyl-D-glucosamine biosynthesis systems of Gram-positive bacteria such as Staphylococcus epidermidis. The PGA polysaccharide adhesin is a critical determinant of biofilm formation. The conserved C-terminal domain of this outer membrane protein is preceded by a variable number of TPR repeats.