<i>HYD</i>-<i>TC</i> and <i>TC</i>-<i>CC</i> correlations (R²) within respective proteins.

The * symbol denotes 2 subunits with weak correlations (ATP6 and ND6) and 4 subunits with small numbers (3 or less in humans) of helices (ND3, ATP8, ND4L, and CO2). The analysis includes the following 13 metazoan animal groups: Porifera, Cnidaria, Mollusca, Crustacea, Hexapoda, Chelicerata, Nematoda, Platyhelminthes, Echinodermata, Fishes, Amphibia, Eutheria, and Aves.