title: Interactions of the transmembrane polymeric rings of the Salmonella enterica serovar Typhimurium type III secretion system.
abstract: The type III secretion system (T3SS) is an interspecies protein transport machine that plays a major role in interactions of Gram-negative bacteria with animals and plants by delivering bacterial effector proteins into host cells. T3SSs span both membranes of Gram-negative bacteria by forming a structure of connected oligomeric rings termed the needle complex (NC). Here, the localization of subunits in the Salmonella enterica serovar Typhimurium T3SS NC were probed via mass spectrometry-assisted identification of chemical cross-links in intact NC preparations. Cross-links between amino acids near the amino terminus of the outer membrane ring component InvG and the carboxyl terminus of the inner membrane ring component PrgH and between the two inner membrane components PrgH and PrgK allowed for spatial localization of the three ring components within the electron density map structures of NCs. Mutational and biochemical analysis demonstrated that the amino terminus of InvG and the carboxyl terminus of PrgH play a critical role in the assembly and function of the T3SS apparatus. Analysis of an InvG mutant indicates that the structure of the InvG oligomer can affect the switching of the T3SS substrate to translocon and effector components. This study provides insights into how structural organization of needle complex base components promotes T3SS assembly and function.
authors.affiliation: Department of Immunology, University of Washington, Seattle, Washington, USA.
authors.forename: Sarah
authors.initials: S
authors.lastname: Sanowar
authors.forename: Pragya
authors.initials: P
authors.lastname: Singh
authors.forename: Richard A
authors.initials: RA
authors.lastname: Pfuetzner
authors.forename: Ingemar
authors.initials: I
authors.lastname: André
authors.forename: Hongjin
authors.initials: H
authors.lastname: Zheng
authors.forename: Thomas
authors.initials: T
authors.lastname: Spreter
authors.forename: Natalie C J
authors.initials: NC
authors.lastname: Strynadka
authors.forename: Tamir
authors.initials: T
authors.lastname: Gonen
authors.forename: David
authors.initials: D
authors.lastname: Baker
authors.forename: David R
authors.initials: DR
authors.lastname: Goodlett
authors.forename: Samuel I
authors.initials: SI
authors.lastname: Miller
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D011485:Protein Binding; D055503:Protein Multimerization; D012486:Salmonella typhimurium / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D026901:Membrane Transport Proteins
references.citation: Proteomics. 2003 Aug;3(8):1454-63
references.pmid: 12923771
references.citation: J Comput Chem. 2004 Oct;25(13):1605-12
references.pmid: 15264254
references.citation: Science. 2010 May 21;328(5981):1040-3
references.pmid: 20395475
references.citation: Nature. 2009 Dec 24;462(7276):1011-5
references.pmid: 19946264
references.citation: Nat Struct Mol Biol. 2009 May;16(5):477-85
references.pmid: 19396171
references.citation: Mol Microbiol. 2001 Feb;39(3):652-63
references.pmid: 11169106
references.citation: Microbiol Mol Biol Rev. 2004 Dec;68(4):771-95
references.pmid: 15590783
references.citation: Structure. 2009 Feb 13;17(2):255-65
references.pmid: 19217396
references.citation: Proc Natl Acad Sci U S A. 2000 Jun 6;97(12):6640-5
references.pmid: 10829079
references.citation: Biol Proced Online. 2004;6:23-34
references.pmid: 15103397
references.citation: PLoS Pathog. 2010 Apr 01;6(4):e1000824
references.pmid: 20368966
references.citation: Microbes Infect. 2002 Jan;4(1):75-82
references.pmid: 11825778
references.citation: Proc Natl Acad Sci U S A. 2007 Nov 6;104(45):17656-61
references.pmid: 17978193
references.citation: Proc Natl Acad Sci U S A. 2000 Sep 26;97(20):11008-13
references.pmid: 10984518
references.citation: Mol Microbiol. 1995 Jul;17(1):169-81
references.pmid: 7476203
references.citation: Adv Appl Microbiol. 2008;65:141-97
references.pmid: 19026865
references.citation: Biophys Rev. 2010 Feb;2(1):21-27
references.pmid: 20174447
references.citation: Science. 2004 Nov 5;306(5698):1040-2
references.pmid: 15528446
references.citation: Proteomics. 2003 Jun;3(6):870-8
references.pmid: 12833510
references.citation: Mol Gen Genet. 1994 Apr;243(1):112-8
references.pmid: 8190064
references.citation: Nat Struct Mol Biol. 2009 May;16(5):468-76
references.pmid: 19396170
references.citation: Anal Chem. 2008 Nov 15;80(22):8799-806
references.pmid: 18947195
references.citation: Science. 1998 Apr 24;280(5363):602-5
references.pmid: 9554854
references.citation: Nature. 2006 Jun 1;441(7093):637-40
references.pmid: 16738660
references.citation: Nature. 2005 Jun 2;435(7042):702-7
references.pmid: 15931226