Fig. 2

pAsa9 map. The pAsa9 sequence and features were visualized with Artemis and DNAPlotter [51, 54]. Going inwards from the scale (expressed in kbp), the first two circles mark ORFs (forward, then reverse strand) using the colour code introduced in Fig. 1. The third ring marks insertion sequences. The fourth marks GC skew, using the following colours: purple: below average; yellow: above average