Fig. 1: The genetic compartmentalization of S. ambofaciens linear chromosome.

The terminal inverted repeats (TIRs, 200 kb) and the origin of replication (oriC) are indicated. The distribution of gene presenting features of interest are represented in blue or red when enriched in the central region or within the extremities (defined by the first and last rDNA operons), respectively (see Supplementary Table 2 for statistical analysis of the data). The dot and asterisk indicate the position of pSAM2 and a complete prophage, respectively. The position of the SMBGCs encoding the biosynthesis of all known antibacterial compounds of S. ambofaciens ATCC 23877 is also indicated. The level of synteny along the chromosome of S. ambofaciens ATCC 23877 is represented as a heat map of gene order conservation (GOC) scores using a sliding window (8 CDSs with 1 CDS step). Each line corresponds to the GOC profile of the reference against another species. The 124 species are organized from the phylogenetically closest to the furthest compared to S. ambofaciens. The vertical black dotted line represents the location of the dnaA gene delineating the two replicators. “NA” (in yellow) indicates the absence of orthologs in the corresponding window. S. ambofaciens ATCC 23877 also harbors a circular pSAM1 plasmid (≈89 kb). Abbreviations: ‘Actino. Sign. CDSs’ (coding sequences of the actinobacterial signature); BGC (biosynthetic gene cluster); ‘C.’ (congocidine BGC); ‘Chr.’ (whole chromosome); GIs (genes belonging to genomic islands); ‘K.’ (kinamycin BGC); ‘Persist_.>0.95 CDSs’ (coding sequences of S. ambofaciens ATCC 23877 presenting a gene persistence superior to 95% in 124 other Streptomyces genomes); ‘Transl. CDSs’ (genes encoding functions involved in translation process and/or RNA stability); NAPSFs (nucleoid-associated proteins and structural factors); SMBGCs (specialized metabolite BGCs); ‘Sp.’ (spiramycin BGC); ‘St.’ (stambomycin BGC); ‘rRNA’ (ribosomal RNA).