Logo Logo
Switch language to English
Schreiner, Patrick (2008): Structural investigation of two supramolecular complexes of the eukaryotic cell: the proteasome and the mitochondrial TOM complex. Dissertation, LMU München: Fakultät für Chemie und Pharmazie



Preface This study is focussed on the structural investigation of large molecular assemblies such as the 26S proteasome and the translocation machinery of the outer mitochondrial membrane. It is divided in two chapters and in both parts the structural and further functional analysis is based on X-ray crystallography. Chapter 1: Structural investigation of Rpn13, the multifunctional adaptor protein of the 26S proteasome The results in chapter 1 reveal that the multifunctional adaptor protein Rpn13 acts as a novel ubiquitin receptor of the 26S proteasome and deliver structural and biophysical details of its interaction with ubiquitin and with other proteasomal subunits. The crystal structure of the ubiquitin binding domain of Rpn13 reveals the molecular architecture of a Pleckstrin Homology (PH) domain and the NMR structure of the complex with ubiquitin shows a novel ubiquitin-binding mode. Additional NMR studies and domain mapping by truncation analysis provide further insights in the domain architecture of Rpn13 and the interaction with its partners Rpn2 and Uch37. Chapter 2: Crystallographic studies of the TOM core complex Chapter 2 presents the purification and crystallization of the mitochondrial protein translocase, the TOM core complex, from Neurospora crassa. Preliminary crystallographic data lead to the determination of space group and cell dimensions. This chapter also describes various experiments to improve the diffraction quality of the crystals and the co-crystallization of TOM core complex with specific monoclonal antibody fragments. Furthermore, expression and refolding of the main component Tom40 is raised as an alternative approach in structural investigation of the TOM complex.