Phylogenetic and Phyletic Studies of Informational Genes in Genomes Highlight Existence of a 4th Domain of Life Including Giant Viruses (original) (raw)
Figure 1
NCLDV proteins involved in DNA, RNA and protein biosynthesis.
The frames on the right represent DNA processing steps with related enzymes found in NCLDVs, and the frames on the left with grey backgrounds show viruses that have the corresponding enzymes. The first frame from the top right corresponds to the dNTP biosynthesis catalyzed by RNR and ThyA. The second frame shows four enzymes involved in DNA replication: DNAP B, TopoIIA, PCNA and FEN. Proteins involved in these two DNA biosynthesis steps were found in diverse large DNA viruses, such as NCLDVs, Herpesviridae and Myoviridae. The third frame represents the DNA transcription step, in which the RNAP II and the transcription factor TFIIB are involved; viral homologs of these proteins are only found in NCLDVs. The last frame shows Mimiviridae amino-acyl tRNA synthetases (aa tRNA synthetase) involved in mRNA translation. Interestingly, viral lineages were consistently less well represented from nucleotide to protein biosynthesis, with the exception of NCLDVs, which were represented in each step. a.a., amino acid.