Database of articles cited by EMDB/PDB/SASBDB data

Keywords
Structure methods	All X-ray diffraction NMR electron microscopy small angle scattering neutron diffraction fiber diffraction powder diffraction infrared spectroscopy EPR fluorescence transfer theoretical model Hybrid
Author
Journal
IF	>30 >20 >10 >5 all

Title	Structure and assembly of pilotin-dependent and -independent secretins of the type II secretion system.
Journal, issue, pages	PLoS Pathog, Vol. 15, Issue 5, Page e1007731, Year 2019
Publish date	May 13, 2019
Authors	S Peter Howard / Leandro F Estrozi / Quentin Bertrand / Carlos Contreras-Martel / Timothy Strozen / Viviana Job / Alexandre Martins / Daphna Fenel / Guy Schoehn / Andréa Dessen /
PubMed Abstract	The type II secretion system (T2SS) is a cell envelope-spanning macromolecular complex that is prevalent in Gram-negative bacterial species. It serves as the predominant virulence mechanism of many ...The type II secretion system (T2SS) is a cell envelope-spanning macromolecular complex that is prevalent in Gram-negative bacterial species. It serves as the predominant virulence mechanism of many bacteria including those of the emerging human pathogens Vibrio vulnificus and Aeromonas hydrophila. The system is composed of a core set of highly conserved proteins that assemble an inner membrane platform, a periplasmic pseudopilus and an outer membrane complex termed the secretin. Localization and assembly of secretins in the outer membrane requires recognition of secretin monomers by two different partner systems: an inner membrane accessory complex or a highly sequence-diverse outer membrane lipoprotein, termed the pilotin. In this study, we addressed the question of differential secretin assembly mechanisms by using cryo-electron microscopy to determine the structures of the secretins from A. hydrophila (pilotin-independent ExeD) and V. vulnificus (pilotin-dependent EpsD). These structures, at approximately 3.5 Å resolution, reveal pentadecameric stoichiometries and C-terminal regions that carry a signature motif in the case of a pilotin-dependent assembly mechanism. We solved the crystal structure of the V. vulnificus EpsS pilotin and confirmed the importance of the signature motif for pilotin-dependent secretin assembly by performing modelling with the C-terminus of EpsD. We also show that secretin assembly is essential for membrane integrity and toxin secretion in V. vulnificus and establish that EpsD requires the coordinated activity of both the accessory complex EpsAB and the pilotin EpsS for full assembly and T2SS function. In contrast, mutation of the region of the S-domain that is normally the site of pilotin interactions has little effect on assembly or function of the ExeD secretin. Since secretins are essential outer membrane channels present in a variety of secretion systems, these results provide a structural and functional basis for understanding the key assembly steps for different members of this vast pore-forming family of proteins.
External links	PLoS Pathog / PubMed:31083688 / PubMed Central
Methods	EM (single particle) / X-ray diffraction
Resolution	1.75 - 3.7 Å
Structure data	0326 6i1x EMDB-0326, PDB-6i1x: Aeromonas hydrophila ExeD Method: EM (single particle) / Resolution: 3.7 Å 0327 6i1y EMDB-0327, PDB-6i1y: Vibrio vulnificus EpsD Method: EM (single particle) / Resolution: 3.4 Å PDB-6i2v: Pilotin from Vibrio vulnificus type 2 secretion system, EpsS. Method: X-RAY DIFFRACTION / Resolution: 1.75 Å
Chemicals	ChemComp-1PE: PENTAETHYLENE GLYCOL / precipitantYM / Polyethylene glycol ChemComp-EDO: 1,2-ETHANEDIOL / Ethylene glycol ChemComp-SO3: SULFITE ION / Sulfite ChemComp-SO4: SULFATE ION / Sulfate ChemComp-HOH*: WATER / Water
Source	aeromonas hydrophila (bacteria) vibrio vulnificus (bacteria)
Keywords	PROTEIN TRANSPORT / PROTEIN BINDING / Pilotin / T2SS / V.vulnificus / Outer-membrane