Fig. 1.

Helical wheel projection of residues Met-1 to Arg-34 of the GCN4-pAA sequence. The view is from the N terminus. Heptad repeat positions are labeled a through g. GCN4-pAA differs from the recombinant dimeric leucine-zipper peptide GCN4-pR by alanine substitutions at four e and four g positions (bold). The sequences of GCN4-pR and GCN4-pAA (with the eight mutated e and g positions set in italics) are as follows: GCN4-pR, MK VKQLEDK VEELLSK NYHLENE VARLKKL VGER; GCN4-pAA, MK VKQLADA VEELASA NYHLANA VARLAKA VGER. The GCN4-pR sequence contains an additional Met-Lys-Val and no Arg-Met at its N terminus but is otherwise identical to GCN4-p1.