Fig. 12. Dot representation of computer-generated base compositions at the second base position in the codon, which were selected by judging whether imaginary proteins translated under the GNC coding system satisfy the four structural conditions (hydropathy, _-helix, _-sheet and _-turn formabilities) for appropriate three-dimensional structure formation. Base compositions at the second codon position were plotted against GC contents of the selected genes out of the computer-generated hypothetical genes.