Distribution of 5-methyldeoxycytidine in products of staphylococcal nuclease digestion of nuclei and purified DNA.

Journal Article (Journal Article)

We have compared the distribution of 5-methyldeoxycytidine (m5dC) between staphylococcal nuclease (SN) sensitive and resistant regions of human diploid fibroblast chromatin to the corresponding distribution in purified DNA. After SN digestion of fibroblast nuclei or purified DNA, nuclease-resistant products were separated from sensitive products by perchloric acid or ethanol precipitation; the radioactively labeled nucleosides were then fractionated by high-performance liquid chromatography and quantitated. Our results indicate that m5dC is preferentially associated with SN-resistant regions of both chromatin and purified DNA. The magnitudes of these preferences in fibroblast chromatin and DNA are similar; we find that the enrichment of m5dC content in SN-resistant fractions of nuclei and DNA relative to the corresponding sensitive fractions is approximately 2-3-fold. Therefore, highly methylated regions of DNA have an intrinsic resistance to digestion by SN that is of sufficient magnitude to explain the high degree of nuclease resistance of chromatin containing highly methylated DNA.

Full Text

Duke Authors

Cited Authors

  • Barr, FG; Kastan, MB; Lieberman, MW

Published Date

  • March 12, 1985

Published In

Volume / Issue

  • 24 / 6

Start / End Page

  • 1424 - 1428

PubMed ID

  • 3986183

International Standard Serial Number (ISSN)

  • 0006-2960

Digital Object Identifier (DOI)

  • 10.1021/bi00327a021


  • eng

Conference Location

  • United States