What is the role of the turn residues selected in the cyclic polyamides?

1) How is the polyamide binding to androgen receptor (AR) elements an example of allostery in biological molecule interactions?

2) What is the role of the turn residues selected in the cyclic polyamides? Why were different types used?

3) In what ways is the structural information (X-ray crystallography) key to the design of the polyamides and their potential uses?

4) Discuss on the paper not more than 10 sentences.