FIGURE 1.

The proposed arrangement of ATP-binding sites in Pdr5. Pdr5 is an asymmetric ABC transporter. A, one ATP-binding site is deviant and comprises the Walker A and B from the N-terminal NBD and the signature and D-loop regions from the C-terminal NBD. The second site comprises canonical motifs. The major alterations in the motifs are shown in white lettering. The arrangement conforms to bioinformatic analysis described elsewhere (10). B, the initial mutations made in this study and their locations in the ATP-binding sites are illustrated.