Figure 1

Comparison of the genetic organization of three TPS islands in different meningococcal strains. Each island consists from the 5’ to the 3’ end of a tpsB, a tpsA, and a variable number of tpsC cassettes interspersed with intervening ORFs (IORFs) (open arrows). The tpsA genes and tpsC cassettes can display very different domains of ~450 bp at their 3’ end as indicated by the different colors. Domains with very high sequence similarity are indicated with the same color. Also the IORFs show high heterogeneity and IORFs with high sequence similarity are indicated with the same color. Note that tpsA or tpsC genes with similar sequences at their 3’ end are always followed by IORFs with high sequence similarity. Regions with high sequence similarity between the different islands are indicated by grey shading, indicating gross rearrangements in the organization between the islands. Note that strain MC58 contains five tpsA genes, including two tpsA genes of system 1 (Figure S1 in Additional file 1). The island depicted here contains the tpsA1b gene with locus tag NMB0497.