FIGURE 1.

Proposed GAG biosynthetic system and current model of the Ica system of Staphylococcus epidermidis. A, diagram of the co-regulated five gene cluster located on chromosome 3 involved in GAG biosynthesis. B, schematic representation of the ica operon from S. epidermidis. C, comparative model of the biosynthetic pathways of GAG and PNAG/polysaccharide intercellular adhesin polysaccharides from A. fumigatus and S. epidermidis, respectively. M, membrane; CW, cell wall; ECM, extracellular matrix. The synthase complex is red; deacetylase is green; epimerase is teal, and other modifying enzymes are tan.