Alignment of the region around intervening sequence (IVS I) in selected Brucella and O. anthropi. Fragments of the alignment where all sequences are identical are not shown. The whole alignment with numbering is given in Additional file 5. Sequence fragments shared by B. microti and Brucella sp. B01 are in blue. Sequence fragments shared by B. microti and O. anthropi are in green. Other regions are in red. Fragments of the alignment highlighted in yellow correspond to the terminal nucleotides of the secondary structures represented in Figure 4.