title: L-pilin variants of Neisseria gonorrhoeae MS11.
abstract: Phase- and antigenic variation of pilin expression in Neisseria gonorrhoeae is based on the genetic exchange between silent pilin genes (pilS) and the pilin expression locus (pilE). Similarly, the non-piliated L-variants of strain MS11, which show an increased resistance to certain antibiotics, are the result of recombination with the pilE locus. However, this recombination is atypical in that pilE(L) carries a tandem arrangement of a complete pilin gene and additional partial pilin genes under the control of the same pilE promoter. Since the two pilin gene copies are tandemly arranged and are often in the same translational frame, oversized pilin molecules are produced, which do not assemble into pili. The tandem gene copies introduced in a pilE(L) locus originate from silent loci where they are already joint. Upon reversion to the P+ phenotype the L-variants lose one pilin gene copy from the pilE(L) in a process reminiscent of the deletion events that otherwise lead to the formation of the non-revertible and non-piliated Pn mutants of MS11 gonococci. Thus deletion of pilin genes from pilE can be regarded as a third mechanism of pilin variation in gonococci.
authors.affiliation: Department of Microbiology and Immunology, University of Adelaide, Australia.
authors.forename: P A
authors.initials: PA
authors.lastname: Manning
authors.forename: A
authors.initials: A
authors.lastname: Kaufmann
authors.forename: U
authors.initials: U
authors.lastname: Roll
authors.forename: J
authors.initials: J
authors.lastname: Pohlner
authors.forename: T F
authors.initials: TF
authors.lastname: Meyer
authors.forename: R
authors.initials: R
authors.lastname: Haas
mesh_terms: D000595:Amino Acid Sequence; D000940:Antigenic Variation; D001425:Bacterial Outer Membrane Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000276:immunology; D001483:Base Sequence; D015139:Blotting, Southern; D002872:Chromosome Deletion; D003001:Cloning, Molecular; D036781:Fimbriae Proteins; D015964:Gene Expression Regulation, Bacterial; D014644:Genetic Variation; D008969:Molecular Sequence Data; D005810:Multigene Family; D009344:Neisseria gonorrhoeae / Q000235:genetics*; D011401:Promoter Regions, Genetic; D011995:Recombination, Genetic
chemical_list: D001425:Bacterial Outer Membrane Proteins; D036781:Fimbriae Proteins