Sequence comparison of the α-hairpins with the anti-parallel coiled-coil structures.

Sequences of the RLS (or RLT) motif from six adaptor proteins are aligned. The corresponding heptad positions are shown above the sequence. The three conserved residues in the RLS (or RLT) motif are indicated by arrows. The12 RLS (or RLT) motif residues are in a box, which was used in the MacA-HlyD12 hybrid. The 18 and 24 residues used in the construction of MacA-HlyD18 and MacA-HlyD24, respectively, are indicated (D18 and D24). The amino acid numbering is based on the protein precursors. In the sequence alignment, Ec, Pa, Aa, and Mh stand for E. coli, P. aeruginosa, Actinobacillus actinomycetemcomitans, and Mannheimia haemolytica, respectively.