FIG 2.

ArlC encodes an OmpT family protease. (A) Alignment of ArlC from AIEC strain NRG857c with OmpT and OmpP from Escherichia coli. The red arrows indicate active site residues, and surface-exposed regions are boxed in red. (B) Cleavage of the FRET substrate 2Abz-SLGRKIQI-K(Dnp)-NH₂ by strain NRG857c and ΔPI-6 and ΔarlC mutants. Fluorescence is shown in relative fluorescence units (RFU). Data are the means ± standard deviations (error bars) from triplicate determinations and were performed twice. (C) Cleavage of the FRET substrate 2Abz-SLGRKIQI-K(Dnp)-NH₂ by NRG857ΔPI-6 mutant containing either pCR2.1 or pCRarlABC.