Whole-genome alignment of the most complete and composite genomes of “Ca. Actinomarinales”. Genomes have been linearized and rearranged to start at the dnaA gene. Synteny and sequence similarity are indicated by vertical lines connecting the genomes. Flexible genomic islands (fGI) have been highlighted in different colors. fGI for genes involved in cell wall biosynthesis and modifications (marked in red), genes related to membrane transport (marked in orange), and genes coding for a restriction-modification system I-III (marked in purple) are highlighted. The region containing the heliorhodopsin gene and two nuo clusters are marked in green. Blue and yellow triangles indicate the presence of the MACRhodopsin and tRNA-direct repeat genomic islands, respectively. At the bottom of the figure, panel 1 shows the location of noncoding RNA (ncRNA), panel 2 shows the locations of tRNA and rRNA genes, panel 3 shows GC content, and panel 4 shows nucleotide signatures.