A conserved DNA sequence is required for efficient gonococcal pilin antigenic variation.
Antigenic variation of the Neisseria gonorrhoeae pilus occurs when a variant pilin sequence from a silent locus recombines into the expression locus by predominantly unidirectional, homologous recombination. At the 3' end of all pilin loci lies a conserved DNA sequence, called the Sma/Cla repeat, which has sequence similarity to several recombinase-binding sites, and therefore may be involved in pilin recombination. We have developed a novel reverse transcriptase/polymerase chain reaction (RT-PCR) assay for direct monitoring of pilin recombination, and both RT-PCR and phase variation were used to examine pilin recombination in a gonococcal strain that had had the pilE Sma/Cla repeat removed. Results from these experiments showed a decrease in pilin recombination when the Sma/Cla sequence was deleted from the expression locus, showing that a specialized site (Sma/Cla) is involved in efficient pilin recombination.
Wainwright
L A
LA
Department of Microbiology/Immunology, Northwestern University Medical School, Chicago, Illinois 60611.
Pritchard
K H
KH
Seifert
H S
HS
D000940:Antigenic Variation / Q000235:genetics*; D000942:Antigens, Bacterial / Q000235:genetics* / Q000276:immunology; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics* / Q000276:immunology; D001426:Bacterial Proteins / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites; D004254:DNA Nucleotidyltransferases / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics*; D036781:Fimbriae Proteins; D010861:Fimbriae, Bacterial / Q000276:immunology*; D005798:Genes, Bacterial; D019426:Integrases; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009344:Neisseria gonorrhoeae / Q000235:genetics* / Q000276:immunology; D016133:Polymerase Chain Reaction; D045522:Recombinases; D011995:Recombination, Genetic; D012091:Repetitive Sequences, Nucleic Acid; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D045522:Recombinases; D036781:Fimbriae Proteins; D004254:DNA Nucleotidyltransferases; D019426:Integrases; C115006:integron integrase IntI1