Structural Biology of T. cruzi TBP-Associated Factor 9 as Potential Target for Drug Design

STRADELLA MF, GÓMEZ BARROSO JA, PEREIRA C, AGUILAR CF

San Luis

Congreso; XXVII Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2009

Sociedad de Biología de Cuyo

Trypanosoma cruzi is the etiologic agent of Chagas’ disease. The objective of our work is the resolution by X-ray crystallography of the three-dimensional structure of T. cruzi proteins involved in the energetic metabolism as a first step for rational drug design based on the structure. The T. cruzi protein studied in this work is TcTAF9 (TATA Binding Protein Associated Factor 9). It is expressed in E. coli as a fusion protein with N-terminal His-tag. We have over-expressed, solubilized and purified the protein for crystallization and other structural assays. We have also constructed a model for TAF9 using the homology modeling method with the MODELLER program. The model helped to predict some aspects of the function of the protein inside the cell. According to TAF9 sequence, which contains a Walker motif (G-X-X-G-X-G-K), we hypothesized that this protein would function as an adenylate kinase (AdK). This was confirmed by catalytic assays. Our results showed that the protein was in its native state allowing to start doing crystallization assays.