The research described in this thesis aimed to evaluate the intrinsic DNA curvature ofthe region of the TP53 tumour suppressor gene that codes for the sequence-specific DNA-binding domain of the p53 protein, a key protein that protects the cell from chemical insultsand tumourogenesis. There have been no previous attempts to experimentally investigate theintrinsic DNA curvature within TP53 or its relation to the functional or structural properties ofthe gene, such as DNA repair and nucleosomal architecture. The present study usedtheoretical models of TP53 in concert with an atomic force microscopy based experimentalinvestigation of TP53 DNA molecules to analyse intrinsic DNA curvature within the gene. Thiswas achieved by developing a novel software platform for the atomic force microscopy basedinvestigation of DNA curvature, named ADIPAS. Dinucleotide wedge models of DNA curvaturewere used to model TP53 in order to investigate the relationship between intrinsic DNAcurvature and the structure and function of the gene. ADIPAS was applied to atomic forcemicroscopy images of TP53 DNA molecules immobilised on a mica surface in order toexperimentally measure intrinsic DNA curvature. The experimental findings were compared totheoretical models of intrinsic curvature in TP53. The resulting intrinsic curvature profilesshowed that exons exhibited significantly lower intrinsic DNA curvature than introns withinTP53, this was also shown to be true for regions of slow DNA repair. This indicated that DNAcurvature may play a role in TP53 as a controlling factor for nucleosomal architecture tofacilitate open chromatin and active DNA transcription. The evolutionary selection for intrinsiccurvature may have played a role in the development of exons with low intrinsic DNAcurvature. Low intrinsic curvature in exon position has also been implicated in the reducedefficiency of DNA repair in a number of cancer specific mutation hotspots.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:678298 |
| Date | January 2012 |
| Creators | Bayliss, Sion |
| Publisher | Swansea University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://cronfa.swan.ac.uk/Record/cronfa42829 |
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