Fig. 4.

Best matches for (A) the Gβγ zzz/xxz ratio and (B) GRK2-Gβγ complex zzz/xxz ratio (right). Colors indicate the quality of the match (100% = exact). (C) If Gβγ does not reorient, adding a constraint for intensity change yields possible orientations of both Gβγ and the GRK2-Gβγ complex. Using all three available measurements narrows the range of possibilities. (D) Orientation of Gβγ if the orientation of the complex is assumed. Use of two measurements helps to narrow down the best matches. For (C) and (D), matches may be further limited down by adding an additional requirement that the positions of Gβγ be physically as well as mathematically allowed (dark overlay).