Fig 2.

Restriction analysis of genomic DNA of H. pylori strains. Genomic DNA of H. pylori strains 26695, 26695-REd, J99, JP26, and J166 (from top panel to bottom panel) was digested with each of the four active 26695 strain-specific type II restriction endonucleases or their isoenzymes—HpyAII, HpyAIII, HpyAIV, and HpyAV (left to right)—or was not digested (control). The genomic DNA of 26695 and 26695-REd was not digested by any of the four restriction enzymes, indicating that all of the HpyAII, HpyAIII, HpyAIV, and HpyAV restriction sites were protected by methylation. Restriction endonucleases, HpyAII, and HpyAV digested the genomic DNA of strain J99, whereas the HpyAIII and HpyAIV restriction sites in J99 were protected by methylation. REs HpyAIII, HpyAIV, and HpyAV digested the genomic DNA of J99, while the HpyAII restriction sites were protected by methylation; HpyAII, HpyAIV, and HpyAV digested J166 genomic DNA, while the HpyAIII restriction sites were protected by methylation.