# List two residues never to be in contact.
4 HIS 11 HIS
4 HIS 12 HIS
4 HIS 13 HIS
5 HIS 12 HIS
5 HIS 13 HIS
5 HIS 14 HIS
7 HIS 20 HIS
7 HIS 21 HIS
7 HIS 22 HIS
7 HIS 23 HIS
7 HIS 24 HIS
8 HIS 20 HIS
8 HIS 21 HIS
8 HIS 22 HIS
8 HIS 23 HIS
8 HIS 24 HIS
11 HIS 19 HIS
11 HIS 22 HIS