FIG. 2.

Predicted impact of insertional mutagenesis on helical amphipathicity of TagB. Residues 6 to 25 of TagB (WT) are shown in helical wheel analysis. The sequence of each residue is indicated, and polar residues are shaded gray. Helical wheel analyses of TagB variants containing insertions of up to four residues at position 10 are also depicted (denoted +1, +2, +3, and +4, respectively). The specific amino acids inserted at position 10 are indicated by black circles. Note the change in the distribution of polar residues (shaded gray) resulting from amino acid insertion such that the amphipathic face of the helix is disrupted by insertion of up to three residues but is restored by insertion of four residues.