In:
Journal of Bacteriology, American Society for Microbiology, Vol. 187, No. 4 ( 2005-02-15), p. 1276-1286
Abstract:
Neisseria gonorrhoeae (the gonococcus) is an obligate human pathogen and the causative agent of the disease gonorrhea. The gonococcal pilus undergoes antigenic variation through high-frequency recombination events between unexpressed pilS silent copies and the pilin expression locus pilE . The machinery involved in pilin antigenic variation identified to date is composed primarily of genes involved in homologous recombination. However, a number of characteristics of antigenic variation suggest that one or more recombinases, in addition to the homologous recombination machinery, may be involved in mediating sequence changes at pilE . Previous work has identified several genes in the gonococcus with significant identity to the pilin inversion gene ( piv ) from Moraxella species and transposases of the IS 110 family of insertion elements. These genes were candidates for a recombinase system involved in pilin antigenic variation. We have named these genes irg for invertase-related gene family. In this work, we characterize these genes and demonstrate that the irg genes do not complement for Moraxella lacunata Piv invertase or IS 492 MooV transposase activities. Moreover, by inactivation of all eight gene copies and overexpression of one gene copy, we conclusively show that these recombinases are not involved in gonococcal pilin variation, DNA transformation, or DNA repair. We propose that the irg genes encode transposases for two different IS 110 -related elements given the names IS Ngo2 and IS Ngo3 . IS Ngo2 is located at multiple loci on the chromosome of N. gonorrhoeae , and IS Ngo3 is found in single and duplicate copies in the N. gonorrhoeae and Neisseria meningitidis genomes, respectively.
Type of Medium:
Online Resource
ISSN:
0021-9193
,
1098-5530
DOI:
10.1128/JB.187.4.1276-1286.2005
Language:
English
Publisher:
American Society for Microbiology
Publication Date:
2005
detail.hit.zdb_id:
1481988-0
SSG:
12
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