Figure 2. 19F-NMR spectra of A2AR (IMAGE) Tokyo Institute of Technology Caption 19F-NMR spectra of A2AR (red box) identifies two activation states (orange peaks on left) used to couple to cognate (Gs) and one state (blue peak on left) to non-cognate (Go) G proteins (TM6) while TM7 labeling reveals dynamic differences (right peaks) between Gs and Go bound A2AR. Dual TM6 activation states enable greater diversity of coupling partners while TM7 dynamics dictates coupling efficacy. Credit Nature Chemical Biology Usage Restrictions Credit must be given to the creator. Only noncommercial uses of the work are permitted. No derivatives or adaptations of the work are permitted. License CC BY-NC-ND Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.