The Salmonella typhimurium InvH protein is an outer membrane lipoprotein required for the proper localization of InvG.
The secretion of pathogenicity factors by Salmonella typhimurium is mediated by a type III secretion system that includes an outer membrane protein of the secretin family. Related secretins are also required for f1 phage assembly and type II secretion. When the C-terminal 43 amino acids of the S. typhimurium secretin InvG are added to f1 pIV, the chimeric f1 pIV-'InvG43 protein becomes dependent on the co-expression of another gene, invH, for function in phage assembly. [3H]-palmitic acid labelling, globomycin sensitivity and density gradient flotation were used to demonstrate that InvH is an outer membrane lipoprotein that is processed by signal peptidase II. A complex between chimeric f1 pIV-'InvG43 and InvH was demonstrated in vivo. InvH was shown to be required for the proper localization of InvG in the outer membrane and for the secretion of the virulence factor SipC. These results suggest that InvH and InvG are part of the functional outer membrane translocation complex in type III secretion systems.
Daefler
S
S
The Rockefeller University, New York, NY 10021, USA. daefles@rockvax.rockefeller.edu
Russel
M
M
D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001425:Bacterial Outer Membrane Proteins / Q000032:analysis / Q000378:metabolism*; D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001435:Bacteriophages / Q000502:physiology; D002458:Cell Fractionation; D002499:Centrifugation, Density Gradient; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism / Q000821:virology; D008074:Lipoproteins / Q000032:analysis / Q000378:metabolism*; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D008969:Molecular Sequence Data; D017830:Octoxynol; D019308:Palmitic Acid / Q000378:metabolism; D010455:Peptides; D011233:Precipitin Tests; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012486:Salmonella typhimurium / Q000235:genetics / Q000254:growth & development / Q000378:metabolism* / Q000472:pathogenicity; D012697:Serine Endopeptidases / Q000187:drug effects / Q000378:metabolism; D010948:Viral Plaque Assay; D019065:Virus Assembly / Q000502:physiology
D000900:Anti-Bacterial Agents; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; C079729:InvH protein, Salmonella; D008074:Lipoproteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D010455:Peptides; D011993:Recombinant Fusion Proteins; C094578:Salmonella invasion protein C; C090991:invG protein, Salmonella typhimurium; D019308:Palmitic Acid; C017339:globomycin; D017830:Octoxynol; D012697:Serine Endopeptidases; C026515:type I signal peptidase