The amino acids in an alpha helix are arranged in a right-handed helical structure, 5.4 Å (= 0.54 nm) wide. The helix has 3.6 residues per turn. The amino-acid side chains are on the outside of the helix, and point roughly downwards. Alpha helices have particular significance in DNA binding motifs, including helix-turn-helix motifs, leucine zipper motifs and zinc finger motifs.

2BNI: Is a General Control Protein, that is invovled with amino acid biosyhthesis.

1CE9: Interacts Selectively with DNA of a specific nucleotide composition (e.g. GC Rich DNA) Binding with a Specific Sequence Motif or Type of DNA (e.g. Promotor Binding or DNA Binding.)