Figure 5. Phylogenetic analysis of the CID sequences from different lineages of organisms.

The phylogenetic tree was constructed by the neighbour-joining method based on the CID sequences: five from Archaea, eighteen from Bacteria, twelve from Fungi, five from Plantae, three from early eukaryotes, eight from early Animalia, and nine from vertebrates (V) including six from mammals. The sequence names, corresponding GI numbers, and abbreviations are listed in Fig. 2 and Table S2. All the sequences were obtained from the protein database at the NCBI.