Phylogenetic relationships among plastid chaperonin 60 proteins. A phylogenetic tree was constructed using the Maximum-likelihood and Bayesian methods. Sequences from Viridiplantae, Rhodophyta and other eukaryotic groups containing chloroplasts of red algal origin are shown in green, red, and blue, respectively. GI numbers or locus IDs of proteins are shown with names of species. Proteins highlighted by yellow boxes were examined in this study. Bootstrap values by RaxML  and posterior probability values by MrBayes  are indicated at the branch nodes. Only the clades containing cyanobacterial and plastid proteins are shown; the whole tree is shown in Additional file 1.