Figure 1

Rankings of amino acid composition in three kingdoms of life. Frequency rankings for 20 alpha amino acids in eubacteria, archaebacteria and 10 selected eukaryotic representatives: Saccharomyces cerevisiae (Sc), Abrabidopsis thaliana (At), Caenorhaditis elegans (Ce), Drosophila melanogaster (Dm), Apis mellifera (Am), Danio rerio (Dr), Gullus gallus (Gg), Mus musculus (Mm), Pan troglodytes (Pt), and Homo sapiens (Hs). The status of genome was labeled as: ^(a) complete annotation, ^(b) draft assembly, ^(c) in progress. The numbers of genomes from the three life kingdoms of archaebacteria, eubacteria and eukaryotes are presented after the kingdom names. For each taxa or life kingdom, the amino acids were ranked in descending order of their frequencies in the whole proteome. Amino acids are colored by the number of codons: red, orange, green, blue, and gray stands for 6, 4, 3, 2, and 1 codons respectively. An amino acid is marked with "√ " if it was detected by Miller's spark tube experiments, otherwise, marked with "-".