Fig. 6.

Coupling of H5 to EL2 motion in the Y223F mutant of Meta II. Rows extracted from 2D ¹³C DARR NMR spectra acquired of the activated Meta II state of wild-type rhodopsin (gray line) and the Y223F (blue line) and Y306F (green line) mutants. The rows show the Cβ region of Cys110^3.25 and Cys187^EL2 and were taken through the diagonal resonances of Cys110^3.25 (A and B) and Cys187^EL2 (C and D). Mutation of Tyr223^5.58 alters the chemical shift of Cys187^EL2 with respect to wild-type rhodopsin (gray line). However, a mutation of Tyr306^7.53 does not influence the wild-type chemical shift for the Cβ of Cys187^EL2.