Fig. 3.

(a–c) Normalized CD distributions for domains used by three of the largest metabolic networks in bacteria. As in the genomewide comparison, the thermophilic (red squares) curves are visibly shifted toward higher contact density relative to the mesophilic (blue triangles) curves. (d) The distribution of differences in average contact density between thermophilic and mesophilic realizations of the same metabolic network for all metabolic networks implicated in the use of 20 domains or more. All such differences are positive, suggesting that all metabolic networks studied here use more designable proteins in thermophilic organisms than in their mesophilic counterparts.