PsiI, a Novel Restriction Endonuclease Recognizing the DNA Sequence 5'-TTA^vTAA-3'

M. A. Abdurashitov^1*, O. A. Belichenko¹, N. A. Lebedeva¹, and S. Kh. Degtyarev²

¹SibEnzyme Co., ul. Akademika Timakova 9, Novosibirsk, 630117 Russia; fax: (3832) 33-6853; E-mail: se_info@ma.nsc.ru

²Institute of Molecular Pathology and Experimental Biochemistry, Siberian Branch of the Russian Academy of Sciences, ul. Akademika Timakova 2, Novosibirsk, 630117 Russia; fax: (3832) 33-6853

^* To whom correspondence should be addressed.

Received October 5, 1998; Revision received December 4, 1998

---

PsiI, a novel restriction endonuclease produced by the bacterial strain Pseudomonassp. SE-G49, has been isolated and characterized. The enzyme cleaves DNA in the middle of its palindromic recognition sequence 5'-TTA^vTAA-3'. Thus, PsiI belongs to a rare group of type II restriction endonucleases whose recognition sites consist of AT base pairs only.

---

KEY WORDS: DNA hydrolysis, Pseudomonas species, site-specificity, restriction endonucleases

---