title: Phase variation of the gonococcal siderophore receptor FetA.
abstract: FetA, the recently characterized gonococcal ferric enterobactin receptor, exhibited extremely rapid phase variation between high- and low-expression levels. The frequency of phase variation was approximately 1.3% in both directions in gonococcal strain FA1090. FetA expression in the 'high phase' was significantly greater than the level of expression in the 'low phase'. Expression levels correlated with the number of cytosine residues in a string of cytosines located close to the transcriptional start site for fetA between the putative -10 and -35 consensus sequences. Antibody production against FetA commonly occurs in infected patients, and we therefore hypothesize that phase variation reflects a balance between the advantages of being able to use a ferric siderophore as an iron source and evasion of the host immune response.
authors.affiliation: Departments of Microbiology and Immunology and Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. sdb@med.unc.edu
authors.forename: S D
authors.initials: SD
authors.lastname: Carson
authors.forename: B
authors.initials: B
authors.lastname: Stone
authors.forename: M
authors.initials: M
authors.lastname: Beucher
authors.forename: J
authors.initials: J
authors.lastname: Fu
authors.forename: P F
authors.initials: PF
authors.lastname: Sparling
mesh_terms: D000469:Alkaline Phosphatase; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D001483:Base Sequence; D018844:Cyclin-Dependent Kinases / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D009344:Neisseria gonorrhoeae / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D011066:Poly C / Q000235:genetics; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D011956:Receptors, Cell Surface / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000378:metabolism
chemical_list: D001425:Bacterial Outer Membrane Proteins; C093120:FrpB protein, bacteria; D011956:Receptors, Cell Surface; D011993:Recombinant Fusion Proteins; D011066:Poly C; D018844:Cyclin-Dependent Kinases; D000469:Alkaline Phosphatase