title: The Salmonella enterica serovar Typhi type IVB self-association pili are detached from the bacterial cell by the PilV minor pilus proteins.
abstract: Salmonella enterica serovar Typhi and some strains (Vi+) of serovar Dublin use type IVB pili to facilitate bacterial self-association, but only when the PilV proteins (potential minor pilus proteins) are not synthesized. Pilus-mediated self-association may be important in the pathogenesis of enteric fever. We have shown previously that the extent of DNA supercoiling controls the rate of Rci-catalyzed inversion of a DNA fragment which includes the C-terminal portions of the PilV proteins. This inversion therefore controls PilV synthesis as a high inversion rate prohibits transcription of pilV-encoding DNA. Here, we describe the manner in which PilV protein expression inhibits bacterial self-association and present data which suggest that incorporation of one or a few PilV protein molecules into a growing pilus, comprised of PilS subunits, causes the pilus to detach at the bacterial membrane. The bacteria are then unable to self-associate. We suggest that this phenomenon may be relevant to the pathogenesis of typhoid fever.
authors.affiliation: Department of Biochemistry, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
authors.forename: Connie K P
authors.initials: CK
authors.lastname: Tam
authors.forename: Christina
authors.initials: C
authors.lastname: Morris
authors.forename: Jim
authors.initials: J
authors.lastname: Hackett
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism*; D010861:Fimbriae, Bacterial / Q000378:metabolism*; D012485:Salmonella typhi / Q000378:metabolism / Q000472:pathogenicity* / Q000648:ultrastructure
chemical_list: D001426:Bacterial Proteins; C077573:PilV protein, Bacteria