Fig. 4

Evolutionary divergence. A neighbour-joining tree is shown which was bootstrapped at a cut-off of 50 %. These values are mentioned on the nodes in the circular un-rooted tree. The coloured branches depict established cyclases from eukaryotes (dark green), established cyclases from prokaryotes (light green) and nucleotide cyclase-like proteins from Actinobacteria (orange), Bacteroidetes (blue) and Proteobacteria (purple). The analysis involved 113 proteins and was conducted using MEGA 6. Details on gene IDs of established cyclases is provided in the supplementary material (Additional file 2)