This proposal is devoted to the development and application of tools for solving challenging problems in structural biology with NMR spectroscopy and computational methods. This will be achieved through interactions between investigators at Harvard, MIT and the Rowland Institute. The research plan is focused on structural problems related to control of gene expression and on development of technology to solve these problems. It builds on the complementary expertise and the common interests of the scientists involved. Component #1 (Gerhard Wagner, Timothy Havel, Jeffrey Hoch), NMR and Data Reduction Techniques for Large Biomolecules, will develop the experimental and computational technologies needed to characterize the structure and dynamics of macromolecular complexes. Component #2 (Gerhard Wagner), Protein-DNA and Protein-Protein Interactions of Transcriptional Activators, is focused on the interaction and specificity of interactions, of transcriptional activators with proteins and nueleic acids. Component #3, (Gregory Verdine) Transcriptional Activation by the NFAT-AP-DNA complex, will study interactions of the transcriptional activators NFAT and AP- 1, which control 11-2 expression in leukocytes, with their promoter region. Component #4 (James Williamson), Isotope Labeling of RNA and DNA with 2H and 13C, is focused on methods for producing isotope labeled RNA and DNA and on protein-RNA interactions. Core A (Administration), to be managed by G. Wagner, will provide administrative support to all participants of this program project. Core B (NMR Technology), also managed by G. Wagner, will make the most recent developments in NMR technology available for use in the above projects and port experiments between different brands of spectrometers. Core C (Data Reduction and modeling), managed by T. Havel, will provide support with structure calculations and with novel data processing methods.