Inhibition of Sma I, Ava I, Nae I, and Xma I endonuclease activities by the methylation of DNA with Hpa II methylase

제한효소 Sma I, Xma I, AVa I, Nae I의 DNA절단반응에 있어서 Hpa II methylation의 억제효과

  • 최우성 (한국과학기술원 생물공학과) ;
  • 강선철 (한국과학기술원 생물공학과) ;
  • 서정선 (서울대학교 의과대학 생화학교실 및 암연구소) ;
  • 유욱준 (한국과학기술원 생물공학과)
  • Published : 1986.06.01

Abstract

The DNA methylated by Hpa II methylase was not cleaved by Sma, I, Ava I and Nae I endonucleases. This experimental data could be interpreted as strong evidences that Sma I, Ava I and Nae I methylases which yet to be isolated would methylate on the inmost cytosine nucleotide within their hexameric recognition sequences. The facts that Sma I, Ava I and Nae I endonucleases can not cleave the DNA methylated by Hpa II methylase are the valuable informations for protecting DNAs upon cleavage reactions by Sma I, Ava I and NAe I endonucleases especially for cDNA insertion experiments into vector DNAs using Sma I, Ava I and Nae I oligonucleotide linkers. In the case of Xma I endonuclease, partially cleaved DNA fragments were observed although the reaction rate was greatly decreased. This result implies that the methylation site of Xma I methylase which yet to be isolated would not be the same as that of Hpa II methylase in Xma I sequence.

Keywords

restriction modification engyme;DNA protein interaction