Role of the 2-amino group of deoxyguanosine in sequence recognition by EcoRI restriction and modification enzymes.

نویسندگان

  • P Modrich
  • R A Rubin
چکیده

The dG residues within the EcoRI recognition sequence of ColE1 DNA have been selectively replaced with dI. Methylation of the altered sequence by the EcoRI modification enzyme is extremely slow as compared with methyl transfer to the natural recognition site. Since the affinity of the modification enzyme for the dI-containing sequence is considerably less than that for the natural sequence, we have concluded that the 2-amino group of dG has an important role in DNA site recognition by this enzyme. In contrast, the altered site is subject to cleavage by EcoRI endonuclease at rates essentially identical with those observed with the natural sequence. These results strongly suggest that the two enzymes utilize different contacts within the EcoRI site and are consisted with our conclusion (Rubin, R. A., and Modrich, P. (1977) J. Biol. Chem. 252, 7265-7272) that the two proteins interact with their common recognition sequence in different ways.

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عنوان ژورنال:
  • The Journal of biological chemistry

دوره 252 20  شماره 

صفحات  -

تاریخ انتشار 1977