Figure 1.

Species distribution following amino-acid compositions. Factorial plane representation, with Correspondence analysis, for the distribution of species following amino acid compositions. Species names are reported whenever possible (for full list see Additional file 1). Amino acids (one letter) are represented in green. Coding colours for hyperthemophiles, thermophiles, prokaryotic mesophiles, psychrophiles and eukaryotes are following legend in Figure 1A. Three main groups, corresponding to hyperthermophiles-thermophiles; prokaryotic mesophiles-psychrophiles and eukaryotes are roughly delimited by horizontal dashed grey lines. A: Legend for colour coding symbols. Species and barycenters symbols for the various groups that are reported in Figures 1, 2, 3 and 4 with the same colour coding conventions.