3rx9

Publication Abstract from PubMed

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

Towards a Structural Comprehension of Bacterial Type VI Secretion Systems: Characterization of the TssJ-TssM Complex of an Escherichia coli Pathovar.,Felisberto-Rodrigues C, Durand E, Aschtgen MS, Blangy S, Ortiz-Lombardia M, Douzi B, Cambillau C, Cascales E PLoS Pathog. 2011 Nov;7(11):e1002386. Epub 2011 Nov 10. PMID:22102820^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.