An alternative DNA structure is necessary for pilin antigenic variation in Neisseria gonorrhoeae.
Pathogens can use DNA recombination to promote antigenic variation (Av) of surface structures to avoid immune detection. We identified a cis-acting DNA sequence near the antigenically variable pilin locus of the human pathogen, Neisseria gonorrhoeae. This 16-base pair guanine (G)-rich sequence was required for pilin Av and formed a guanine quartet (G4) structure in vitro. Individual mutations that disrupted the structure also blocked pilin Av and prevented nicks required for recombination from occurring within the G4 region. A compound that binds and stabilizes G4 structures also inhibited pilin Av and prevented nicks from occurring on the G-rich strand. This site constitutes a recombination initiation sequence/structure that directs gene conversion to a specific chromosomal locus.
Cahoon
Laty A
LA
Northwestern University Feinberg School of Medicine, 303 East Chicago Avenue, Chicago, IL 60611, USA.
Seifert
H Steven
HS
D000940:Antigenic Variation; D020029:Base Pairing; D001483:Base Sequence; D004249:DNA Damage; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics*; D036781:Fimbriae Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology*; D010861:Fimbriae, Bacterial; D005785:Gene Conversion; D006147:Guanine / Q000737:chemistry; D008652:Mesoporphyrins / Q000378:metabolism / Q000494:pharmacology; D009344:Neisseria gonorrhoeae / Q000235:genetics* / Q000254:growth & development / Q000276:immunology*; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D011995:Recombination, Genetic
D004269:DNA, Bacterial; D008652:Mesoporphyrins; D009838:Oligodeoxyribonucleotides; C074063:pilE protein, Neisseria gonorrhoeae; D036781:Fimbriae Proteins; C031468:mesoporphyrin IX; D006147:Guanine