Figure 5

Structural model of the amino-terminal half of actinopterygian HIF2α showing sites putatively under positive selection. Twenty-three residues potentially under positive selection (MSA Codons 219–577, Table 3) mapped to a structural model of the N-terminal half of HIF2α based upon mouse HIF2α50. Two residues shown as purple spheres make contacts at the dimer interface between HIF2α and HIFβ and three residues shown as blue spheres contact an anti-cancer drug (0X3) known to interfere with subunit dimerization in mammals50. Eighteen other residues potentially under positive selection are shown as orange spheres. The upper and lower images are rotated by 180° around the indicated plane. Conserved DNA-binding (bHLH) and protein dimerization (PAS-A, PAS-B) domains are indicated at the top.