Partially disordered ligand. The fluorescein moiety of the ligand molecule (F6Z A1356) is missing in the electron density of the thyroxine-binding globulin, PDB entry 2xn7
(Qi et al., 2011), even in 0.4σ noise-level 2mFo − DFc density. The 1.43 Å resolution mFo − DFc map contoured at ±3σ (green/red) and 2mFo − DFc maximum-likelihood omit map contoured at 1σ (blue) are shown. Maps were calculated for a refined model with the ligand atoms omitted.