Abstract: The present invention relates to crystalline human farnesyl diphosphate synthase (FPPS), to the three-dimensional structure of free FPPS as well as the three-dimensional structures of FPPS in complex with substrates such as IPP (isopentenyl diphosphate) and/or with inhibitors such as Zometa® or Aredia®. Further, methods for preparing crystals of human FPPS are described. According to the invention the crystals can be used to determine the structures of FPPS homologs mutants, complexes with ligands, FPPS crystal forms and similar molecules of unknown structure. The invention further relates to the use of FPPS crystals to select new FPPS ligands, e.g. by X-ray screening and to design and/or identify inhibitors against FPPS. Furthermore, the invention relates to NMR methods for selecting and/or identifying new low molecular weight binders to FPPS, which represent new therapeutic agents.

Abstract: The present invention concerns protein kinase C (PKC) theta, in particular, the three-dimensional structure of the catalytic domain of PKC theta. Methods of expression, purification and crystallization of PKC theta catalytic domain are provided in preparation for crystallography. The atomic coordinates of a complex of PKC theta complexed with an inhibitor are also provided.