Figure 1.

Four potential I-A^k binding registers of HEL(42-61). On the unfolding of HEL during antigen processing, the I-A^k P1 pocket has the potential to bind to one of four Asp or Asn residues within HEL(42-61), resulting in four separate registers. These four registers are underlined with the predicted P1 anchors in italics and corresponding auxiliary pockets labeled P4, P6, P7, and P9. Register 1 of the immunodominant HEL(48-61) peptide (shaded box) is established by Asp52 (solid-outline box) anchoring at the P1 pocket. The three additional putative P1 anchors, Asn44, Asn46, and Asp48 are shown in dotted-outline boxes.