Figure 4.

Proposed schematic model of NBDs showing the relative positions of different nucleotide- and effector-binding sites. MANT-ATP binding is prevented by preincubation with antiprogestin RU-486 and bound MANT-ATP is displaced by Ru-486, suggesting the existence of a cytosolic steroidal-interacting region adjacent to the ATP-binding site. Since the flavonoid binding is prevented by preincubation with ATP and RU-486, bound flavonoids most likely cover both ATP site and the vicinal steroid site. MANT, 2'(3')-N-methylanthraniloyl [3].