Table 2.

Restriction endonucleases isolated from six H. pylori strains

H. pylori strain	Designation of endonuclease	Recognition site	Isoschizomer	Units of activity/g cells
60190	HpyII	GAAGA	MboII	1.7  × 102
	HpyIV	GANTC	HinfI	5.2  × 102
	HpyV	TCGA	TaqI	1.8  × 103
	HpyVIII	CCGG	HpaII	2.3  × 102
J178	Hpy178II	GAAGA	MboII	2.3  × 10
	Hpy178III	TCNNGA	None	1.5  × 102
	Hpy178VI	GGATG	FokI	2.3  × 102
	Hpy178VII	GGCC	HaeIII	2.8  × 103
J188	Hpy188I*	TCNGA	None	1.3  × 103
	Hpy188III	TCNNGA	Hpy178III	6.2  × 10
J99	Hpy99I	CGWCG	None	1.6  × 10
	Hpy99II	GTSAC	Tsp45 I	8.0  × 102
	Hpy99III	GCGC	HhaI	2.9  × 103
CH4	HpyCH4I	CATG	NlaIII	1.4  × 102
	HpyCH4II	CTNAG	DdeI	1.6  × 102
	HpyCH4III	ACNGT	Tsp4CI	1.4  × 103
	HpyCH4IV	ACGT	MaeII	3.1  × 10
	HpyCH4V	TGCA	CviRI	2.1  × 102
	HpyCH4VI	TCNNGA	Hpy178III	4.5  × 10
J166	Hpy166I	TCNGA	Hpy188I	2.4  × 103
	Hpy166II	GTNNAC	MjaIV	7.3
	Hpy166III	CCTC	MnlI	5.4

Enzymes with new specificities are written in bold. 

^*Purification and cloning of this restriction system are described in ref. 21.