Figure 4.

Alignment of the C-terminal region of cytochrome b. All available tunicate species and representatives of remaining deuterostomes are shown. Identical and conserved residues are shown by reverse contrast with black and dark gray background, respectively. Similar residues are indicated by light gray background. The "ENK" consensus sequence of non-ascidian proteins is highlighted by asterisks. Numbers refer to amino acid position. Species classification and AC number of the analysed sequences are listed in Additional file 2.