fig5

Figure 5. Coupled conformational changes in TMDs (A) Definition of the average helix rotation angle <HRA> and the average helix tilting angle <HTA>. After superposition of either NBD1 or NBD2, pairs of aligned helices are analyzed with one serving as a reference helix. The helix rotation angle (HRA, in degree) is defined as the angle between a pair of vectors from two equivalent, aligned helices (red and green). Each vector v1 (red) or v2 (green) joins the two neighboring CA atoms. The average helix rotation angle <HRA> is the average over all HRAs defining the length of the helix. The helix tilt angle (HTA, in degree) is computed between a pair of cross-vectors cv1 and cv2 from the two equivalent helices. Each cross-vector is defined by three consecutive CA atoms of a helix. The average helix tilt angle <HTA> is the average of all HTAs over the length of the helix. (B) correlation of <HRA> and <HTA> with DCOM for helices in the TMD1 domain (C) correlation of <HRA> and <HTA> with DCOM for helices in the TMD2 domain