FIG. 2.

Predicted topology of the outer membrane β-barrel AlgE. Predicted transmembrane β sheets are indicated in regular text (nonboldface), extracellular loops at the top are indicated in boldface, and periplasmic turns at the bottom are indicated in boldface. Locations where the FLAG epitopes were inserted are indicated by triangles, and the positions (relative to the position of the cleavage of the signal peptide) are indicated; black numbers, the insertion was permissive, i.e., alginate production was restored; gray numbers, the insertion was nonpermissive. The deleted region of loop 7 is indicated by regular gray text (nonboldface).