Fig. 5.

Phylogenetic tree of nog1-bearing E. coli and Shigella strains and species carrying nog1-like sequences. On the left, phylogenetic tree of representative bacterial strains containing a nog1 or nog1-like open reading frame within citC. The tree was inferred using the Maximum Likelihood method and is based on a concatemer of 16 s RNA, atpD, adk, gyrB, purA, and recA, thus, independent of citC and nog1 respectively. The percentage of trees which clustered together in 1000 bootstrap replicates is shown next to the branches. Helicobacter was used as out-group. On the right, an alignment of nog1 and nog1-like sequences within citC of the strains is shown. Black, sequence parts which can be aligned to nog1 of EHEC using BLAST2 and which might be translated; turquoise, N-terminal methionine; pink, translational stop; blue, frame shift mutation (which destroyed both, nog1 and citC); red, insertion of IS1 and duplicated amino acids ProAlaIle around the insertion site; this insertion also destroys nog1 and citC. Orange, regions likely not to be translated; green, insertion element in some Salmonella and Citrobacter strains, keeping the frames intact