Transcription of the ant gene during lytic growth of

bacteriophage P22 is regulated by the cooperative

binding of two Arc repressor dimers to a 21-base-pair

operator site. Please find the co-crystal structure of this

Arc tetramer-operator complex from PDB.

(a) Make an animation (by Gifbuilder) of whole

complex.

(b) Show the DNA sequences of the Arc operator.

1 E 22 T A T A G T A G A G T G C 2 E 22 T T C T A T C A T

1 F 22 A A T G A T A G A A G C A

2 F 22 C T C T A C T A T

(c) The picture below is the hydrogen bonds between

beta-sheet side chains and DNA bases. Show three side

chains (gln9, asn11, arg13) from one monomer and

corresponding DNA bases of them on your home page.

Color three side chain with different color. Measure the

distance between possible hydrogen bonds.