Back to Search
Start Over
Functional characterization of excision repair and RecA-dependent recombinational DNA repair in Campylobacter jejuni.
- Source :
-
Journal of bacteriology [J Bacteriol] 2009 Jun; Vol. 191 (12), pp. 3785-93. Date of Electronic Publication: 2009 Apr 17. - Publication Year :
- 2009
-
Abstract
- The presence and functionality of DNA repair mechanisms in Campylobacter jejuni are largely unknown. In silico analysis of the complete translated genome of C. jejuni NCTC 11168 suggests the presence of genes involved in methyl-directed mismatch repair (MMR), nucleotide excision repair, base excision repair (BER), and recombinational repair. To assess the functionality of these putative repair mechanisms in C. jejuni, mutS, uvrB, ung, and recA knockout mutants were constructed and analyzed for their ability to repair spontaneous point mutations, UV irradiation-induced DNA damage, and nicked DNA. Inactivation of the different putative DNA repair genes did not alter the spontaneous mutation frequency. Disruption of the UvrB and RecA orthologues, but not the putative MutS or Ung proteins, resulted in a significant reduction in viability after exposure to UV irradiation. Assays performed with uracil-containing plasmid DNA showed that the putative uracil-DNA glycosylase (Ung) protein, important for initiation of the BER pathway, is also functional in C. jejuni. Inactivation of recA also resulted in a loss of natural transformation. Overall, the data indicate that C. jejuni has multiple functional DNA repair systems that may protect against DNA damage and limit the generation of genetic diversity. On the other hand, the apparent absence of a functional MMR pathway may enhance the frequency of on-and-off switching of phase variable genes typical for C. jejuni and may contribute to the genetic heterogeneity of the C. jejuni population.
- Subjects :
- Bacterial Proteins genetics
Campylobacter jejuni radiation effects
DNA Damage radiation effects
DNA Repair Enzymes genetics
DNA Repair Enzymes metabolism
Microbial Viability radiation effects
Mutation
Rec A Recombinases genetics
Ultraviolet Rays
Bacterial Proteins metabolism
Campylobacter jejuni enzymology
Campylobacter jejuni genetics
DNA Repair
Rec A Recombinases metabolism
Recombination, Genetic
Subjects
Details
- Language :
- English
- ISSN :
- 1098-5530
- Volume :
- 191
- Issue :
- 12
- Database :
- MEDLINE
- Journal :
- Journal of bacteriology
- Publication Type :
- Academic Journal
- Accession number :
- 19376866
- Full Text :
- https://doi.org/10.1128/JB.01817-08