FIG. 5.

Cartoon depicting the epitopes recognized by the anti-E2 and anti-CD81 MAbs. (A) Cartoon depicting epitopes recognized by the anti-E2 MAbs. Each box represents aa; the coordinates of the boundaries between the four arbitrarily defined regions (A to D) are shown, together with the 12-aa tag recognized by MAb 11/4b. The HVR as well as regions of E2 implicated in binding CD81 are shaded according to the ability of the MAb to inhibit E2₆₆₁ binding to CD81 (Fig. 6C). (B) Cartoon of CD81 showing the four predicted transmembrane regions (TM1 to TM4). EC2 (hatched rectangle) and amino acid residues which differ between AGM and human CD81 (asterisks) are shown. One or more of these residues are thought to be critical for CD81 to interact with E2. All of the CD81 MAbs (5A6, 1D6, JS81, 4TM-1, and 1.3.3.22) bind to the EC2 region.