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

Journal Article (Journal Article)

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.

Full Text

Duke Authors

Cited Authors

  • Modrich, P; Rubin, RA

Published Date

  • October 25, 1977

Published In

Volume / Issue

  • 252 / 20

Start / End Page

  • 7273 - 7278

PubMed ID

  • 332689

International Standard Serial Number (ISSN)

  • 0021-9258


  • eng

Conference Location

  • United States