contact faces 71A4C1 [-a1 [-protein] -a2 [-nucleic-dna-backbone]]
contact faces FFFF00 [-a1 [-protein] -a2 [-nucleic-dna-sidechain]]
contact faces FF00FF [-a1 [-protein -elem N,O] -a2 [-nucleic -elem N,O] -max-dist 3.5]
