This ribbon diagram shows human TTR with (Z)-5-(3,5-dibromo-4-hydroxybenzylidene)-imino-1-methylimidazolidin-4-one bound to each of the two T4 binding pockets within the tetramer. Monomer subunits are individually colored. The expanded view illustrates part of the T4 binding site with a “Connelly” analytical molecular surface (green, hydrophobic; purple, polar), with hydrogen bonds represented as dashed lines between functional groups.