Fig. 3.

Relative orientation of NDBs. (A) Representative inward‐facing conformations of type I ABC transporter have been structurally aligned at NBD1, shown in gray. The second NBD is shown in white only for Sav1866. Each NBD is reduced to a simplified representation of a triangle that encodes the domain orientation. The corners of the triangle are the center of mass of the NBD, indicated by a sphere, the first residue in the signature sequence helix and the last residue in the helix of the Walker A motif. Transporters harboring a degenerate NBS have warm colors, while transporters with two canonical NBSs have cold colors. (B) Quantification of relative orientation and NBD distances, using the same color code as in A. Open circles mark transporters with a degenerate side.