Fig. 3

Theoretical 3D model of an annelid tetramer based on B. symmytilida D1 sequence and the crystal structure of Lumbricus terrestris (1X9F). Amino acids identified as potentially under positive selection are highlighted. 52Q appears to be in an area where it could participate to the formation of an oligomer. Depicted residues are colored by element; OH: red; NH: blue: C: helix color. Heme group is shown in grey. Model constructed with Modeller (Mod9v13, Eswar et al. 2006).