**4. DNA recombinational repair factors in** *H. pylori*

While some genes that are predicted to be involved in DNA recombinational repair, including *recA, recG, recJ, recR, recN, and ruvABC,* were annotated from the published *H. pylori* genome sequences, many genes coding for the components that are involved in the pre-synapsis stage, such as RecBCD, RecF, RecO, and RecQ, were missing. Considering that *H. pylori* is highly genetic diverse with a high recombination frequency, this has been a big puzzle over the past decade. Recent studies revealed the existence of both pathways, AddAB (RecBCD-like) and RecRO, for initiation of DNA recombinational repair in *H. pylori*. In the following sections we will summarize the current understanding of DNA recombinational repair in *H. pylori* by reviewing the literature accumulated in recent years.
