Locations of the epitopes on HBV capsids and subunits. The cartoon represents three adjacent dimeric subunits on a capsid with the protruding spikes corresponding to the four-helix bundles. The epitopes for Mabs 88, 312, 842, 3105, 9c8, and F11A4 are all located on the apices of the spikes whereas the epitope for Mab 3120 is located between the spikes and involves residues from two adjacent subunits.23; 24; 25; 26; 27 The two copies of the Mab e6 epitope are located near the C-termini of the dimer and are accessible only on free subunits. The locations of the epitopes for Mabs 904 and 905 are uncertain, but epitope 904 may be on the spike apex and 905 near the C-terminus (see text). The positions of the three carboxy-terminal mutations employed to map the e6 epitope, and which affect capsid assembly, are also indicated.