Figure 2From: Discovering structural motifs using a structural alphabet: Application to magnesium-binding sitesThe percentage letter frequency distributions of first-shell amino acid residues (gray), second-shell amino acid residues (white), and all amino acid residues (black) in the Mg2+-proteins. There is a total of 25,406 amino acid residues in the Mg2+-proteins, of which 250 are in the first shell, while 898 are in the second shellBack to article page