Open AccessNovel properties of a restriction endonuclease isolated from Haemophilus parahaemolyticus.
Author(s) -
Dennis G. Kleid,
Zafri Humayun,
Andrea Jeffrey,
Mark Ptashne
Publication year - 1976
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.73.2.293
Subject(s) - restriction enzyme , cleavage (geology) , dna , biology , methylation , genetics , base pair , restriction site , sequence (biology) , endonuclease , nucleic acid sequence , recognition sequence , microbiology and biotechnology , stereochemistry , chemistry , paleontology , fracture (geology)
The sequences in lambda DNA in and around six sites cut by Hph, a restriction enzyme isolated from Haemophilus parahaemolyticus, are compared. The enzyme produces a staggered cut around an AT or TA base pair, but the sequences immediately surroinding the cleavage sites bear no obvious relation to one another. Eight (in some cases nine) base pairs to one side of each cleavage site is the common sequence TCACC AGTGG. Two lines of evidence indicate that these bases constitute part or all of the Hph recognition site. First, mutations in this sequence prevent Hph cutting. Second, dimethylsulfate-mediated methylation of Gs and As in this site prevent cutting, whereas methylation of purines in the region between this sequence and the cleavage sites has no such effect. There is discernible 2-fold rotational symmetry neither in the common sequence nor around the cleavage sites.