Fig. 3.

In vivo tests of potential pentapeptides for PhrH activity. (A) Sequence of the PhrH propeptide. The potential pentapeptides (DRNTT, YKLSD, DHSPY, and KKALS) are underlined. Asterisks indicate the amino acids that were individually mutated. (B) Effects of single mutations in the conserved second amino acid of the four potential pentapeptides on the PhrH activity. The control curve (wt) represents the relative luminescence readings corrected for the OD for the PspoIIG promoter when wild-type rapH and phrH are both overexpressed (BD5263, in red). The remaining curves show the relative luminescence readings corrected for OD for the PspoIIG promoter when the R37 (in orange), K48 (in violet), H44 (in green), or K54 (in blue) residues are changed to alanine. T₀ is indicated by the downward-pointing arrow.