Figure 3.

I-A^k auxiliary pockets tolerate a wide range of peptide anchors. HEL(48-61) auxiliary anchors were individually substituted with aliphatic, nonpolar, polar, and charged residues. The relative binding affinities of these peptides for I-A^k is listed on the right. Highlighted are the individual HEL(48-61) auxiliary anchor substitutions that alone were able to completely prevent peptide binding despite the presence of the strong P1 Asp52: P4 substitutions with Lys, Trp, and Tyr, and P6 substitution with Lys. NB, nonbinding.