FIGURE 1.

Distribution of DTD1 homologs in the phylum of cyanobacteria. The 16 S rDNA phylogenetic tree of entirely sequenced cyanobacteria genomes was constructed using the ribosomal data base project web site. For the sake of clarity, several Prochlorococcus and Synechococcus species, whose genomes are highly homologous to those of other species, were omitted from the figure. The concomitant presence of a DTD1 and of a DTD3 homolog is indicated with an asterisk. The genome size of each cyanobacterium is specified in brackets.