title: Definition of a bacterial type IV secretion pathway for a DNA substrate.
abstract: Bacteria use conjugation systems, a subfamily of the type IV secretion systems, to transfer DNA to recipient cells. Despite 50 years of research, the architecture and mechanism of action of the channel mediating DNA transfer across the bacterial cell envelope remains obscure. By use of a sensitive, quantifiable assay termed transfer DNA immunoprecipitation (TrIP), we identify contacts between a DNA substrate (T-DNA) and 6 of 12 components of the VirB/D4 conjugation system of the phytopathogen Agrobacterium tumefaciens. Our results define the translocation pathway for a DNA substrate through a bacterial conjugation machine, specifying the contributions of each subunit of the secretory apparatus to substrate passage.
authors.affiliation: Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, 6431 Fannin, JFB1.765, Houston, TX 77030, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Cascales
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Christie
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D016960:Agrobacterium tumefaciens / Q000235:genetics* / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism*; D003227:Conjugation, Genetic; D003432:Cross-Linking Reagents; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D005557:Formaldehyde; D007473:Ion Channels / Q000378:metabolism; D008074:Lipoproteins / Q000378:metabolism; D009154:Mutation; D011233:Precipitin Tests; D037521:Virulence Factors / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D003432:Cross-Linking Reagents; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D007473:Ion Channels; D008074:Lipoproteins; C036483:T-DNA; D037521:Virulence Factors; C051583:virE2 protein, Agrobacterium; D005557:Formaldehyde; D000251:Adenosine Triphosphatases