RESUMEN
The discovery of novel small molecules that function as antibacterial agents or cellular probes of biology is hindered by our limited understanding of bacterial physiology and our ability to assign mechanism of action. We previously employed a chemical genomic strategy to identify a novel small molecule, MAC13243, as a likely inhibitor of the bacterial lipoprotein targeting chaperone, LolA. Here, we report on the degradation of MAC13243 into the active species, S-(4-chlorobenzyl)isothiourea. Analogs of this compound (e.g., A22) have previously been characterized as inhibitors of the bacterial actin-like protein, MreB. Herein, we demonstrate that the antibacterial activity of MAC13243 and the thiourea compounds are similar; these activities are suppressed or sensitized in response to increases or decreases of LolA copy number, respectively. We provide STD NMR data which confirms a physical interaction between LolA and the thiourea degradation product of MAC13243, with a Kd of ~150 µM. Taken together, we conclude that the thiourea series of compounds share a similar cellular mechanism that includes interaction with LolA in addition to the well-characterized target MreB.
Asunto(s)
Antibacterianos/farmacología , Proteínas de Escherichia coli/antagonistas & inhibidores , Lipoproteínas/metabolismo , Chaperonas Moleculares/antagonistas & inhibidores , Proteínas de Unión Periplasmáticas/antagonistas & inhibidores , Tiourea/análogos & derivados , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Lipoproteínas/química , Chaperonas Moleculares/metabolismo , Proteínas de Unión Periplasmáticas/metabolismo , Relación Estructura-Actividad , Tiourea/farmacocinética , Tiourea/farmacologíaRESUMEN
Recent genome-scale analyses of genetic interactions in model microbes have revealed the inherent functional organization of the cell as a dense network of highly interconnected pathways. While classical one gene at a time paradigms offer limited insight into cellular systems, genome-scale approaches are making considerable headway. Indeed, where small organic compounds are ideal probes of biological complexity, systematic chemical genomic methods are emerging as requisite and powerful approaches to describing both the small molecule probe and network with which it interacts. Here, we highlight various chemical genomic approaches that are being pioneered in model microbes.