Type II restriction endonucleases from Helicobacter pylori include an enzyme with a novel recognition sequence

Type II restriction endonuclease activities of Helicobacter pylori strain R oberts and of the type strain H. pylori NCTC 11637 were detected and analys ed by conventional techniques. The endonucleases were partially purified, t heir optima for activity and their recognition and cleavage sites were dete rmined. H. pylori (Roberts) contained at least two enzymes: HpyBI was an is oschizomer of RsaI (GT/AC) and NpyBII was of a novel specificity (GTN/NAC). H. pylori NCTC 11637 was found to contain an isoschizomer of EcoRV (HpyCI: GAT/ATC) and at least one other enzyme which was too unstable to character ise, (C) 1999 Federation of European Microbiological Societies. Published b y Elsevier Science B.V. All rights reserved.