Towards a Structural Comprehension of Bacterial Type VI Secretion Systems: Characterization of the TssJ-TssM Complex of an Escherichia coli Pathovar

• DOI: 10.1371/journal.ppat.1002386
• Publication Date: 2011-11-10T16:48:21Z
• Authors: Catarina Felisber...; Eric Durand; Marie-Stéphanie A...; Stéphanie Blangy; Miguel Ortiz-Lomb...; Badreddine Douzi; Christian Cambillau; Eric Cascales
• Keywords: Cell envelope; Colicin

Type VI secretion systems (T6SS) are trans-envelope machines dedicated to the of virulence factors into eukaryotic or prokaryotic cells, therefore required for pathogenesis and/or competition towards neighboring bacteria. The T6SS apparatus resembles injection device bacteriophage T4, and is anchored cell envelope through a membrane complex. This complex composed TssL, TssM TagL inner proteins TssJ outer lipoprotein. Here, we report crystal structure enteroaggregative Escherichia coli Sci1 lipoprotein, two four-stranded β-sheets protein that exhibits transthyretin fold with an additional α-helical domain protruding loop. We showed contacts this loop since depleted mutant failed interact in vitro vivo. Biophysical analysis TssJ-TssM interaction suggest structural model membrane-anchored shell T6SS. Collectively, our results provide improved understanding assembly encourage structure-aided drug design novel antimicrobials targeting