Hydrophobic ligand binding pocket of GRβ. Residues forming the hydrophobic environment for the propynyl group (red circle) are Met556, Leu559, Leu604, Phe619 Ile625 Met635, Gln638, Cys639, and Met642; for the dimethylnitrophenyl group (blue circle) of RU-486, the residues are Asn560, Gly563, Gly564, Val567, Trp596, and Met600.