Skip to main content
. 2002 Dec 15;30(24):5391–5397. doi: 10.1093/nar/gkf686

Figure 1.

Figure 1

Spontaneous deletion and horizontal re-acquisition of the hpyIIRM system. Sequence analysis of the hpyIIRM system in H.pylori strain 26695 identified 80 bp repeats flanking the R-M system. The presence of direct repeat sequences facilitates generation of deletions through mechanisms involving sister-strand exchange or strand slippage. These deletions result in excision of the intervening region and one copy of the repeat. Helicobacter pylori strains lacking the hpyIIRM cassette, but containing one copy of the repeat unit, may re-acquire a functional cassette through transformation. Primers repF and repR flanking the 80 bp repeats were used in PCR to confirm acquisition of hpyIIRM::aphA cassettes by recipient strains. An aphA cassette was inserted into hpyIIR of strain 6a to create strain RA1.