Cell
Volume 85, Issue 7, 28 June 1996, Pages 1089-1099
Journal home page for Cell

Article
p53 Protein Exhibits 3′-to-5′ Exonuclease Activity

https://doi.org/10.1016/S0092-8674(00)81309-4Get rights and content
Under an Elsevier user license
open archive

Abstract

Highly purified p53 protein from different sources was able to degrade DNA with a 3′-to-5′ polarity, yielding deoxynucleoside monophosphates as reaction products. This exonuclease activity was dependent on Mg2+ and inhibited by addition of 5 mM nucleoside monophosphates. This exonuclease activity is intrinsic to the wild-type p53 protein: it copurified with p53 during p53 preparation; only purified wild-type p53, but not identically purified mutant p53 proteins displayed exonuclease activity; the exonuclease activity could be reconstituted from SDS gel-purified and urea-renatured p53 protein and mapped to the core domain of the p53 molecule; and finally, purified p53 protein could be UV cross-linked to GMP. A p53-intrinsic exonuclease activity should substantially extend our view on the role of p53 as a “guardian of the genome.”

Cited by (0)