Hydrophobic interactions observed in the ferredoxin-like fold proteins. (A) Representation of internal conserved hydrophobic contacts. N- and C-terminal compact regions are colored yellow and green, respectively. The conserved hydrophobic residues near the F-value peaks have a space-filling representation. (B) Illustrations of important interactions among the secondary structures discussed in the current study. α helices are shown as circles, and the β strands are shown as triangles. The N- or C-terminal compact regions are colored in yellow or green, respectively, as in (A). The important interactions are indicated in red.