Abstract
Mutations within a conserved “conformational” domain of the p53 protein have frequently been observed in a wide variety of human cancers. A hybrid protein containing the wild-type conformational domain of p53 fused to protein A bound to calf thymus DNA and a specific p53 DNA-binding motif. Hybrid proteins containing mutations in p53 bound to DNA less efficiently than wild-type hybrid protein. In addition, competition experiments showed that mutated p53 DNA-binding motif failed to interact with p53 hybrid proteins. The DNA-binding activity of wild-type p53 hybrid protein was inhibited by the metal chelator 1,10-phenanthroline. These results demonstrate that DNA-binding activity resides in the conformational domain of p53, providing a structural model for disruption of DNA binding by mutation. Furthermore, metal ions may regulate binding of p53 to DNA by modulating its conformation.
Footnotes
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↵1 This work was supported by an Advanced Research Proposal Grant from the Texas Higher Education Coordinating Board (015-033) (S. A. M.); by grants RO1 CA45187 from the National Cancer Institute, NIH; a grant from the Mathers Foundation (J. A. R.); by gifts to the Division of Surgery from Tenneco and Exxon for the Core Lab Facility; by The University of Texas M. D. Anderson Cancer Center Core Grant (NCI CA16672) and the Automated DNA Sequencing Core Facility (NCI 2P30-CA 16672-018).
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↵2 To whom requests for reprints should be addressed.
- Received June 18, 1993.
- Accepted October 5, 1993.
- ©1993 American Association for Cancer Research.
Volume 53, Issue 22
