FIG. 2.

Comparative genomic evidence implicating folX and folM in tetrahydromonapterin synthesis. (A) Phyletic distribution of phenylalanine hydroxylase (phhA), PTPS-II, folM, and folX genes among representative genomes. Note the anticorrelation between PTPS-II and folM or folX. Note also that folM sometimes is unaccompanied by folX, and that folM and folX sometimes occur without phhA. (B) Clustering of folX and folM with each other and with folE in diverse Gammaproteobacteria. In two genomes these genes also cluster with folK. Genes are colored to match Fig. 1C. Arrows indicate the transcriptional direction; overlaps between arrows indicate translational coupling.