MS05-P03 The Crystal Structure of the R280K Mutant of Human p53 Explains the Loss of DNA Binding Ana Luisa Carvalho (UCIBIO-REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal) Ana Sara Gomes (LAQV-REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal) Filipa Trovão (UCIBIO-REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal) Benedita Pinheiro (UCIBIO-REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal) Sara Gomes (LAQV-REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal) Carla Oliveira (CEB—Centre of Biological Engineering, University of Minho, Campus Gualtar, Braga, Portugal) Lucília Domingues (CEB—Centre of Biological Engineering, University of Minho, Campus Gualtar, Braga, Portugal) Maria João Romão (UCIBIO-REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal) Lucília Saraiva (LAQV-REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal)email: almc@fct.unl.ptThe p53 tumor suppressor is widely found to be mutated in human cancer. This protein is regarded as a molecular hub regulating di!erent cell responses, namely cell death. Compelling data have demonstrated that the impairment of p53 activity correlates with tumor development and maintenance [1]. For these reasons, the reactivation of p53 function is regarded as a promising strategy to halt cancer [2]. The recombinant mutant p53R280K DNA binding domain (DBD) was produced for the "rst time, and its crystal structure was determined in the absence of DNA to a resolution of 2.0 Å [3]. The solved structure contains four molecules in the asymmetric unit, four zinc(II) ions, and 336 water molecules. The structure was compared with the wild-type p53 DBD structure, isolated and in complex with DNA. These comparisons contributed to a deeper understanding of the mutant p53R280K structure, as well as the loss of DNA binding related to halted transcriptional activity. The structural information derived may contribute to the rational design of mutant p53 reactivating molecules with potential application in cancer treatment.

Acknowledgments: We thank Gilberto Fronza (from Mutagenesi e Prevenzione Oncologica, Ospedale Policlinico San Martino, Genova, Italy), for providing us with the pLS76 vector. We acknowledge the European Synchrotron Radiation Facility for the provision of synchrotron radiation facilities and access to beamline ID30B. This work received financial support from the European Union (FEDER, Fundo Europeu de Desenvolvimento Regional, funds POCI/01/0145/FEDER/007728 through Programa Operacional Factores de Competitividade–COMPETE) and National Funds (FCT/MCTES, Fundação para a Ciência e Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior) under the Partnership Agreement PT2020 UID/MULTI/04378/2013, and projects (3599-PPCDT) PTDC/DTP-FTO/1981/2014–POCI-01-0145-FEDER-016581 and RECI/BBB-BEP/0124/2012. FCT fellowships: PD/BD/114046/2015 (Ana Sara Gomes) and  SFRH/BD/96189/2013 (Sara Gomes) (thanks FCT PhD Doctoral Programme BiotechHealth), and SFRH/BPD/110640/2015 (Carla Oliveira).
References:

[1] Kim, M. P. & Lozano, G. (2018). Cell Death Di!er., 25, 161–168.

[2] Joerger, A. C. & Fersht, A. R. (2016). Annu. Rev. Biochem., 85, 375–404.

[3] Gomes, A. S., Trovão, F., Pinheiro, B., Freire, F., Gomes, S., Oliveira, C., Domingues, L., Romão, M. J., Saraiva, L & Carvalho, A. L. (2018). International Journal of Molecular Sciences, 19.
Keywords: mutant p53R280K, crystal structure, DNA binding