activity can be inhibited by rationally designed inhibitors. The proprietary LeadBuilder virtual-screening method (Domainex Ltd) was used to screen a database of 80,000 potential protease inhibitors, PROTOCATS, with pharmacophoric and docking filters derived from analysis of the BaSrtB crystal structure . A. Space filling model showing one of the hit compounds fitting into the active site of BaSrtB and interacting with the catalytic cysteine residue. B. MTSET and the hits from the virtual screen were tested in the FRET-based assay at varying concentrations to screen for inhibition of SrtBΔN26 mediated cleavage of d-PVPPKTGDS-e. The most effective compounds were LSHTM40, LSHTM50, and LSHTM52, which had IC50 values of 63.1 ± 8.8, 60.1 ± 4.7 and 44.1 ± 6.9 μM, respectively. The IC50 for MTSET was 286.7 ± 16.6 μM, indicating its inhibitory effect on SrtBΔN26 is less potent than the three identified compounds.