Structure And Function Of BRPF2PHD2and Research On Histone Aceylation Transferase Human MOZ

In this study, the solution structure of the second PHD finger in BRPF2was determined. According to the structure, BRPF2PHD2is an atypical PHD finger with the fold of a traditional PHD finger. BRPF2PHD2was identified to bind DNA and this interaction was conserved in BRPF proteins. The second PHD finger of BRPF2was categorized into a new subset of PHD finger.In chapter1, the definition of epigenetics and post-translational modification of histone were briefly introduced. The composition of eukaryotic chromatin and nucleosome were discussed. Basic unit of eukaryotic chromatin, the nucleosome, consists of～146bp of DNA wrapped in1.67left-handed superhelical turns around the histone octamer, consisting of2copies each of the core histones H2A, H2B, H3, and H4. The unstructured N-termini of histones are subject to such modifications as acetylation, methylation, phosphorylation, ubiquitination, and sumoylation. and biological effect would be induced consequently.In chapter2, the research details of BRPF2PHD2were discussed. BRPF2PHD2possesses a two-strand β sheet which is different from any other PHD fingers. Functionally, this PHD finger can potentially bind DNA non-specifically with an evolutionarily conserved and positively charged surface. According to our results, PZPM of BRPF2possesses both histone tail recognizing and DNA-binding activities, endowing the PZPM of BRPF2the potential to serve as a regulatory module on nucleosome platform. Moreover our work also shed light on the functional aspect of the PZPM.In chapter3, the research on HAT (histone acetylation transferase) activity of human MOZ was discussed. Based on our previous result that the MOZ PHD12could specifically recognize unmodified H3R2and acetylated H3K14, it is possible that MOZ PHD12played a regulatory role in the catalysis of HAT MOZ. We applied reconstituted histone octamer, nucleosome array, reconstituted chromatin with Hela octamer and extracted Hela chromatin as substrates for HAT assay, respectively. The HAT activity of MOZ MYST, MOZ PHD12-MYST and its mutants were measured via3H based HAT assay and meaningful results were obtained.