COA on amino acid usage and frequency distribution of genes on hydrophobicity and pI. (a) Positions of 24 non-halophiles and 6 halophiles on the plane defined by first and second major axes generated from COA on amino acid usage of encoded proteins. High temperature adapted organisms are underlined. (b) Distribution of genes on the basis of hydrophobicity of encoded proteins. (c) Distribution of genes on the basis of predicted pI of encoded proteins. Red and black color indicates halophiles and non-halophiles, respectively. Organism abbreviations are listed in Table 1.