Figure 10. Phylogenetic relationships between 47 exoribonucleases from Cyanobacteria and 5 representative Proteobacteria members of each RNase II and RNase R families.

The phylogenetic tree was constructed based on the result of the global alignment of the 57 exoribonuclease sequences using maximum likelihood at the Phylogeny.fr pipeline (http://www.phylogeny.fr/) (28). A branch length of one substitution/site is given to infer phylogenetic distances. The position of the RNase II/R homologue from Synechocystis sp. PCC6803 in the tree is highlighted with an arrow. Sequences are identified by the following criteria: species are represented by the first two letters of the genus followed by the first two letters of the species name; this is followed by the representative identification code issued from the GenBank database.