Recombination frequencies in NER-deficient H. pylori mutants after natural transformation We next examined the role of the H. pylori NER system in recombination. Each mutant strain was individually transformed with genomic DNA extracted from H. pylori strain J99-R3. This strain contains a point mutation (A1618T) that confers Rif resistance

which can be used as a selection marker to recover recombinant clones (Additional file 2: Figure S2). Recombinant clones were distinguished from spontaneous mutants by partial rpoB sequence analysis. The uvrA mutant exhibited a highly significant decrease of the recombination frequency in comparison to the wild type (Figure 2B). A decreased mean recombination frequency was also determined for the uvrB deficient mutant, {Selleck Anti-diabetic Compound Library|Selleck Antidiabetic Compound Library|Selleck Anti-diabetic Compound Library|Selleck Antidiabetic Compound Library|Selleckchem Anti-diabetic Compound Library|Selleckchem Antidiabetic Compound Library|Selleckchem Anti-diabetic Compound Library|Selleckchem Antidiabetic Compound Library|Anti-diabetic Compound Library|Antidiabetic Compound Library|Anti-diabetic Compound Library|Antidiabetic Compound Library|Anti-diabetic Compound Library|Antidiabetic Compound Library|Anti-diabetic Compound Library|Antidiabetic Compound Library|Anti-diabetic Compound Library|Antidiabetic Compound Library|Anti-diabetic Compound Library|Antidiabetic Compound Library|Anti-diabetic Compound Library|Antidiabetic Compound Library|Anti-diabetic Compound Library|Antidiabetic Compound Library|Anti-diabetic Compound Library|Antidiabetic Compound Library|buy Anti-diabetic Compound Library|Anti-diabetic Compound Library ic50|Anti-diabetic Compound Library price|Anti-diabetic Compound Library cost|Anti-diabetic Compound Library solubility dmso|Anti-diabetic Compound Library purchase|Anti-diabetic Compound Library manufacturer|Anti-diabetic Compound Library research buy|Anti-diabetic Compound Library order|Anti-diabetic Compound Library mouse|Anti-diabetic Compound Library chemical structure|Anti-diabetic Compound Library mw|Anti-diabetic Compound Library molecular weight|Anti-diabetic Compound Library datasheet|Anti-diabetic Compound Library supplier|Anti-diabetic Compound Library in vitro|Anti-diabetic Compound Library cell line|Anti-diabetic Compound Library concentration|Anti-diabetic Compound Library nmr|Anti-diabetic Compound Library in vivo|Anti-diabetic Compound Library clinical trial|Anti-diabetic Compound Library cell assay|Anti-diabetic Compound Library screening|Anti-diabetic Compound Library high throughput|buy Antidiabetic Compound Library|Antidiabetic Compound Library ic50|Antidiabetic Compound Library price|Antidiabetic Compound Library cost|Antidiabetic Compound Library solubility dmso|Antidiabetic Compound Library purchase|Antidiabetic Compound Library manufacturer|Antidiabetic Compound Library research buy|Antidiabetic Compound Library order|Antidiabetic Compound Library chemical structure|Antidiabetic Compound Library datasheet|Antidiabetic Compound Library supplier|Antidiabetic Compound Library in vitro|Antidiabetic Compound Library cell line|Antidiabetic Compound Library concentration|Antidiabetic Compound Library clinical trial|Antidiabetic Compound Library cell assay|Antidiabetic Compound Library screening|Antidiabetic Compound Library high throughput|Anti-diabetic Compound high throughput screening| however, the difference between the uvrB mutant and wild type did not reach statistical significance (BF =14, “strong evidence”). There was no significant

difference between the recombination frequency of the uvrC mutant and the wild type (Figure 2B). The introduction of an intact copy of the uvrA gene into the uvrA mutant restored the recombination frequency to wild type levels. In contrast, the uvrD deletion mutant (ΔuvrD) showed a hyper-recombinational phenotype (Figure 2B) that is in agreement with previous studies in E. coli[26] and in H. pylori[23]. Characterization of the donor DNA imports after recombination in NER-deficient mutants One of the characteristics of H. pylori is the import of relatively short fragments of donor DNA into the recipient chromosome after natural transformation. BIX 1294 research buy In order to understand whether components of the NER system play a role in the control of the length of DNA fragments replaced after natural transformation, and in the

formation of interspersed many sequences of the recipient (ISR), single recombination events were further characterized. For this, Rif resistant clones obtained using the in vitro transformation assay were randomly selected and a 1663 bp fragment in the rpoB locus was sequenced. Recombinant nucleotide sequences were CX-5461 order aligned with both donor and recipient sequences to identify the different import parameters used for graphic comparisons of the polymorphisms (Figure 3). Maximum likelihood estimations (MLE) of the import size were calculated and the total number of ISR found among the isolates was counted. Statistical significance of the results was evaluated using a Bayesian approach (see Methods). Since the uvrA mutant showed a strongly reduced recombination frequency, an allele-specific PCR was used in a pre-screening step to distinguish between spontaneous mutants and recombinant clones. Figure 3 Import patterns after transformation of recipient strain 26695 wild type (wt, left panel) and  uvrC  mutant (right panel) with DNA of Rif resistant strain J99-R3. Each row represents a 1663 bp partial rpoB sequence.