Related Experiment Video
Updated: Jun 27, 2026

Yeast As a Chassis for Developing Functional Assays to Study Human P53
Published on: August 4, 2019
Physical and functional interactions between human mitochondrial single-stranded DNA-binding protein and tumour
Tuck Seng Wong1, Sridharan Rajagopalan, Fiona M Townsley
1Centre for Protein Engineering, Medical Research Council, Hills Road, Cambridge CB2 0QH, UK.
Abstract:
Single-stranded DNA-binding proteins (SSB) form a class of proteins that bind preferentially single-stranded DNA with high affinity. They are involved in DNA metabolism in all organisms and serve a vital role in replication, recombination and repair of DNA. In this report, we identify human mitochondrial SSB (HmtSSB) as a novel protein-binding partner of tumour suppressor p53, in mitochondria. It binds to the transactivation domain (residues 1-61) of p53 via an extended binding interface, with dissociation constant of 12.7 (+/- 0.7) microM. Unlike most binding partners reported to date, HmtSSB interacts with both TAD1 (residues 1-40) and TAD2 (residues 41-61) subdomains of p53. HmtSSB enhances intrinsic 3'-5' exonuclease activity of p53, particularly in hydrolysing 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) present at 3'-end of DNA. Taken together, our data suggest that p53 is involved in DNA repair within mitochondria during oxidative stress. In addition, we characterize HmtSSB binding to ssDNA and p53 N-terminal domain using various biophysical measurements and we propose binding models for both.
More Related Videos
04:56Detection of Aggregation-Prone Behavior in Mutant P53 V157F Breast Cancer Cells Using Multipoint Thioflavin T Fluorescence
Published on: December 30, 2025
06:38High Sensitivity Measurement of Transcription Factor-DNA Binding Affinities by Competitive Titration Using Fluorescence Microscopy
Published on: February 7, 2019
Related Concept Videos
Abnormal Proliferation
DNA Damage can Stall the Cell Cycle
DNA Damage Can Stall the Cell Cycle
Loss of Tumor Suppressor Gene Functions
When the tumor suppressor genes develop mutations or are lost, cells start growing out of control, leading to cancer. However, a single functional copy of the tumor suppressor gene is enough for the cells to maintain their normal functions and cell...
Interactions Between Signaling Pathways
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
Covalently Linked Protein Regulators
These groups modify specific amino acids in a protein.