[A new site-specific endodeoxyribonuclease EcoHI].

A new sitespecific endonuclease of the II class EcoHI has been isolated from Escherichia coli strain and characterized. Restriction endonuclease EcoHI recognises the nucleotide sequence C C (C/G) G G with the cleavage site between the fourth and fifth nucleotide. It is an isoshizomer of the restriction endonuclease CauII. The yield of enzyme is 2500 units of activity per 1 g of biomass. The producing strain Escherichia coli HI is nonpathogenic, easily grown with the antibiotic resistance markers permitting to cultivate the strain under selective conditions.