Transmembrane proteins. Using GROMACS 2024.1 190 , the Martini 3 systems were energy minimized using the steepest descent algorithm, setting the convergence criteria to 100,000 steps and a maximum force of 0.1 kJ mol -1 nm -1 . Position restraints were applied to the backbone beads of the protein (with a force constant of 1000 kJ mol -1 nm -2 ). A short NPT 5 ns-long equilibration was performed with the same position restraints. For Martini 3, we performed a production run of 30 ms for Kir2.2, and two production runs of 30 μs each for the ADP/ATP carrier at 310 K with the standard Martini 3 parameters. The Martini 2 system was prepared following the same protocol and simulated for 30 μs-long with GROMACS 2023.2, using parameters from de Jong et al. .