Figure 5.

Triangle tables of correlation coefficients between amino acids. Triangle tables of correlation coefficients between amino acids in kingdoms of eubacteria (5a), archaebacteria (5b), and eukaryotes (5c). The correlations between 20 amino acids were determined by calculating Pearson correlation coefficients (r) of amino acid frequencies over 495 eubacteria, 44 archaebacteria, and 10 eukaryotic representatives respectively. Each correlation between a pair of amino acids was colored: red (r > 0.8), orange (0.5 <r < 0.8), yellow (0.3 <r < 0.5), blue (r < -0.8), light blue (-0.8 <r < -0.5), light green (-0.5 <r < -0.3) and white for others. The significance (2-tailed) was also listed in the table: ** indicates that the correlation is significant at the 0.05 level (2-tailed), and * indicates that the correlation is significant at the 0.01 level (2-tailed).