Figure 5

Mutation load. Average mutation load L _mut vs AT content for (a),(b) for the epsilon subunit of F1F0-ATP synthase (PDB id. 1aqt, chain A) (c),(d) for the acyl carrier protein (PDB id. 1hy8, chain A) and (e),(f) for the cold-shock protein (PDB id. 1c9o, chain A) as well as for (a),(c),(e) transition-to-transversion ratio k = 2 and (b),(d),(f) k = 20. Symbols are as in Fig. 3, black circles indicate standard genetic code (which are connected by lines for better visibility), whereas the other different colors indicate the seven naturally occurring variants studied, as listed in Fig. 2. The error bars indicate the mean's standard deviation.