A structure-specific endonuclease from cauliflower (Brassica oleracea var. Botrytis) inflorescence

Seisuke Kimura, Mihoko Kai, Hiroyuki Kobayashi, Atsushi Suzuki, Hiroshi Morioka, Eiko Otsuka, Kengo Sakaguchi

Research output: Contribution to journalArticlepeer-review

23 Scopus citations


A protein with structure-specific endonuclease activity has been purified to near homogeneity from cauliflower (Brassica oleracea var. botrytis) inflorescence through five successive column chromatographies. The protein is a single polypeptide with a molecular mass of 40 kDa. Using three different branched DNA structures (flap, pseudo-Y and stem-loop) we found that the enzyme, a cauliflower structure-specific endonuclease, cleaved the single-stranded tail in the 5'-flap and 5'-pseudo-Y structures, whereas it could not incise the 3'-flap and 3'-pseudo-Y structures. The incision points occur around the single strand-duplex junction in these DNA substrates and the enzyme leaves 5'-PO4 and 3'-OH termini on DNA. The protein also endonucleolytically cleaves on the 3'-side of the single-stranded region at the junction of unpaired and duplex DNA in the stem-loop structure. The structure-specific endonuclease activity is stimulated by Mg2+ and by Mn2+, but not by Ca2+. Like mammalian FEN-1, the protein has weak 5'→3' double-stranded DIVA-specific exonuclease activity. These results indicate that the cauliflower protein is a plant structure-specific endonuclease like mammalian FEN-1 or may be the plant alternative.

Original languageEnglish (US)
Pages (from-to)4970-4976
Number of pages7
JournalNucleic acids research
Issue number24
StatePublished - Dec 15 1997
Externally publishedYes

ASJC Scopus subject areas

  • Genetics


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