FIG. 1.

Hypothetical topological model of gonococcal TbpA. Schematic representation of the hypothetical two-dimensional model of gonococcal TbpA proposed previously (5). The horizontal dashed lines represent the boundaries of the outer membrane. The protein sequence is shown as the solid black line, with putative transmembrane β strands shown as vertical boxes. Putative extracellular loops are designated L1 through L11. The open circles represent six conserved cysteine residues. The locations of the HA epitopes inserted during the present study are indicated by dark gray boxes. The previously proposed trypsin cleavage sites are indicated with asterisks. The modified positions of accessible trypsin cleavage sites demonstrated by the present study are shown as black bars.