Modeling of proposed MAb-1G10 binding structures. (A) Model of the phage display peptide CEPLC in stick representation; disulphide bond is depicted in yellow, oxygen and nitrogen atoms are colored red and blue respectively. (B) Cartoon representations of the A33 structure using coordinates from [PDB: 3K7B] . The strand-loop-helix region of the A33 protein similar to the phage display peptide CEPLC (see text) is shown. Leucine and aspartate side chains are depicted in stick representation and the distance between them displayed. (C) Alternative conformational epitope also consistent with phage display data where long-range interactions between A33 residues could be involved; mutational analysis did not support this hypothesis. Distances ~3 Å between polar groups are shown in broken lines.