biostudies-literatureEkstrom AGBiotechnology and Biological Sciences Research CouncilEngineering and Physical Sciences Research Council6310-6313https://www.ebi.ac.uk/biostudies/studies/S-EPMC5708339biostudies-literatureUnknown15(30)We use mass spectrometry analysis and molecular modelling to show the established antimicrobial inhibitor 4,5-dichloro-1,2-dithiol-3-one (HR45) acts by forming a covalent adduct with the target β-ketoacyl-ACP synthase III (FabH). The 5-chloro substituent directs attack of the essential active site thiol (C112) via a Michael-type addition elimination reaction mechanism.Organic & biomolecular chemistryStructural evidence for the covalent modification of FabH by 4,5-dichloro-1,2-dithiol-3-one (HR45).PMC5708339EP/K039717/1BB/N005570/1BB/M003493/1Cockroft SLKelly VMarles-Wright JCampopiano DJEkstrom AGfalseStructural evidence for the covalent modification of FabH by 4,5-dichloro-1,2-dithiol-3-one (HR45).We use mass spectrometry analysis and molecular modelling to show the established antimicrobial inhibitor 4,5-dichloro-1,2-dithiol-3-one (HR45) acts by forming a covalent adduct with the target β-ketoacyl-ACP synthase III (FabH). The 5-chloro substituent directs attack of the essential active site thiol (C112) via a Michael-type addition elimination reaction mechanism.2017-01-01T00:00:00Z2017 Aug2026-04-30T18:09:47.372Z2026-04-07T16:14:29.142ZS-EPMC57083392871500110.1039/c7ob01396e