Fig. 7.

rpoC2 maximum-likelihood tree showing that the four cyanobacterial strains that encode DEAD-box proteins from all three clades of cyanobacterial DEAD-box proteins are closely related. Nucleotide sequences for the RNA polymerase β′ subunit, rpoC2, were aligned by muscle and used to reconstruct a maximum-likelihood tree with G. violaceus PCC 7421 as an outgroup. Several Leptolyngbya species and closely related cyanobacteria, as well as several Synechococcus species, were included to confirm the clustering of the four strains that encode all three DEAD-box proteins. Bootstrap values ≥50 % are shown at the nodes. Branch lengths are proportional to the mean number of substitutions per nucleotide site as indicated by the scale bar. All nodes in the maximum-likelihood tree are duplicated in a neighbour-joining reconstruction, as indicated with a red circle.