Figure 4.

Loss of the non‐oxidative stage of the pentose phosphate pathway (PPP) among Rickettsiales.

Presence and absence of the four key enzymes (rpe: ribulose‐phosphate 3‐epimerase, tla: transaldolase, tkt: transketolase and rpi: ribose 5‐phosphate isomerase) are shown across the 16S rRNA phylogeny of representative members from the Rickettsiales as filled and empty rectangles, respectively. Completeness of the pathway in RiCNE is highlighted. Half‐filled rectangle indicates a truncated rpe gene homologue. The question mark indicates missing data rather than loss of tla homolog from ca. Arcanobacter lacustris since its genome is incomplete (completeness = 48%; Martijn et al., 2015). The asterisk indicates a possible gene fusion event in ca. Arcanobacter lacustris between the rpiB gene and the upstream gene coding for a NAD(P)H: quinone oxireductase. 16S rRNA tree constructions were performed with MrBayes under GTR + G + I. A phylogenetic analysis based on the individual protein sequences is presented in Supporting Information Fig. S5. [Color figure can be viewed at wileyonlinelibrary.com]