Fig. 4.

Structural differences between agonist and antagonist state of MR. (A) Relative dispositions of H5, H6, and H7 between native (gray) and T870L mutant (cyan) hMR LBD, with H5–H6 loop in either open or closed conformation, respectively. R817 disengages from the A-ring ketone carbonyl of spironolactone (black dotted line) in native hMR during MD. Axes of H5 are showed as slender cylinders showing relative tilt. Side-chain carbon atoms of R817 in each model are colored green, nitrogen blue. Ligands carbon atoms are colored coral, oxygen red, sulfur yellow. (B) Relative dispositions of H5, H7, and H8 between native and T870L mutant hMR LBD. Helices of native hMR are also showed as half-transparent cartoon on the right for comparison purposes. Packing of bulky residues F866 and W816 is maintained in both conformations.