Fig. 4.

Variation in the sequence and expression level of manganese import gene cluster troABCD and its regulators. (a) Regulator perR maximum-likelihood tree with heatmap of gene expression TPM values. Mn²⁺-binding lipoprotein troA was more expressed than troBCD and more expressed in APS compared to THY. Some commensal strains with diverged perR and troRABCD copies had reduced troA expression. (b) In addition to sequence variation to the other strains, strains I27, D13 and D20 shared a truncated troABCD gene cluster that lacked SSU_RS09410, a putative membrane protein variably annotated as a pseudogene (shown in blue for T15 and S26) or unannotated by Prokka in different strains, likely due to its short length and truncation.