sfb860Goettingen UniversityMax-Plank-Institute

Projects: Group B

Group B : Dynamics of multi-protein complexes

Title: Structure and dynamics of the yeast mitochondrial presequence translocase

Principal Investigator: Prof. Dr. Peter Rehling info

Summary:
project B1 This project aims to structurally and functionally dissect presequence receptor domains of the S. cerevisiae translocation machinery and to understand how their interactions within the translocase promote the vectorial movement of the precursor across the inner membrane. In this context we aim to extend our successful analyses on the identification of such receptor domains and assess the mechanism underlying their function in transport across the outer and inner membranes. We aim to obtain structural insight into the organization of the translocase and address the dynamics of the presequence translocase associated import motor in order to understand how stimulation of mtHsp70 is timely and spatially coupled to precursor movement.

Title: Coupled binding and folding in multiprotein-complexes

Principal Investigator: Prof. Dr. Markus Zweckstetter info

Summary:
project B2Assembly of dynamic macromolecular complexes usually proceeds in a step-by-step manner and requires conformational flexibility and adaptability of the constituting components during the assembly process. We propose to study coupled binding and folding in the spliceosome and in the TIM23 complex using NMR spectroscopy. In particular, we will focus on the impact of phosphorylation on SR proteins, the structural consequences of RS-RS domain interactions as well as the structural analysis of spliceosomal complexes amenable for NMR spectroscopy. In collaboration with other projects in research area B, we will study the structure of Tim50ims in complex with Tim23ims, with presequences and with Tim21ims. Our ultimate goal is to understand the importance of coupled folding and binding in macromolecular complexes.

Title: Cargo recognition by exportins

Principal Investigator: Prof. Dr. Dirk Görlich info, Prof. Dr. Ralf Ficner info

Summary:
Exportins are essential for eukaryotic life. They mediate biosynthetic nuclear export and counteract leakage of cytoplasmic components into the nuclear compartment. How they recognize their project B3proteinaceous cargoes is an intriguing but still largely unresolved question. We therefore aim at elucidating the structures of the actin·exportin 6·RanGTP, of cargo·exportin 4·RanGTP and cargo·exportin·7·RanGTP complexes as well as of complexes comprising CRM1·RanGTP and nuclear export signals that deviate from the classic PKI- and Rev-NES pattern.

Title: Structure and molecular function of the WD-40 repeat containing autophagy proteins Atg18, Atg21 and Atg16L1

Principal Investigator: Prof. Dr. Michael Thumm info, Dr. Karin Kühnel info

Summary:
WD-40 proteins typically fold as β-propellers and function as platforms for the dynamic association of multi-protein complexes. Our goal is to dissect the composition, structure and function of complexes containing WD-40 autophagy proteins. We focus on mammalian Atg16L1 and the two homologous S. cerevisiae proteins Atg18 and Atg21, which belong to the PROPPIN family, a unique class of phosphoinositide binding WD-40 proteins. We will combine genetic, cell biological, biochemical and structural methods to characterize their complexes and their spatial and temporal dynamics.
project B4

Title: Structural basis of SLP adaptors to control lymphocyte signalling dynamics

Principal Investigator: Prof. Dr. Jürgen Wienands info, Prof. Dr. Christian Griesinger info

Summary:
project B5 The intracellular adaptor protein SLP65 is a key element of antigen-induced B-cell activation, and hence antibody-mediated immune responses. The communication between the B cell antigen receptor (BCR) and SLP65 is unclear. During the first funding period we elucidated the SLP65 structure and identified CIN85 (Cbl-interacting protein of 85 kDa) as a vesicle-associated mediator of BCR/SLP65 interaction. We now plan to analyse the structure of SLP65/CIN85 complexes and their potential subcellular transport via vesicular structures. This will close a gap in our understanding of humoral immunity in mouse and man.

Title: Assembly of the eight-subunit COP9 signalsosome MPN/PCI holocomplex

Principal Investigator: Prof. Dr. Gerhard Braus info

Summary:
The COP9 signalosome (CSN) and the LID of the 26S proteasome consist of six PCI and two MPN domain proteins. CSN and LID are part of super-complexes and act at the interface between signalling pathways and the control of protein half-life. We propose for the next funding period a comparative study between CSN and the LID and their sub-complexes, their topology including interacting proteins, their composition and the order of assembly. Therefore we will combine fungal genetics with and structural methods.
project B6

Title: Molecular mechanism, structural organization and dynamics of the pyruvate dehydrogenase multienzyme complex

Principal Investigator: Prof. Dr. Kai Tittmann info

Summary:
project B7 Central goal of the project is to elucidate the molecular mechanism of bacterial and human pyruvate dehydrogenase multienzyme complex by a rigorous characterization of substrate processing in and channeling between the different components conjointly with the structural and dynamic analysis of fully assembled complex and functional subcomplexes in chemically or functionally defined substates along the pathway. The studies are aimed to identify structural and dynamic determinants that define and dictate the timing and synchronization of substrate channeling and the mode of interaction in a symmetric multienzyme complex.

Title: Structure-function analysis of nuclear export complexes and their interaction with nucleoporins

Principal Investigator: Prof. Dr. Ralph Kehlenbach info, Prof. Dr. Ralf Ficner info

Summary:
project B8 CRM1 is the major export receptor for transport of proteins and protein-RNA complexes out of the nucleus. The goal of this project is to understand the dynamic interactions between CRM1, RanGTP, cargos, adaptors, and nucleoporins at the structural, the biochemical and the cell biological level. We are using crosslinking approaches, single-particle electron microscopy, X-ray crystallography as well as cell-biological assays to characterise CRM1 in complexes with the nucleoporin Nup214 and/or 7-methyl-guanosine-capped UsnRNAs.

Title: Computational methods for modelling macromolecular complexes

Principal Investigator: Dr. Michael Habeck info

Summary:
project B9The integration of diverse data is often the only practical approach to characterise the structure of macromolecular complexes. This project aims to develop robust and versatile computational tools for combining data from solution and solid-state NMR, cryo-EM, SAXS and mass spectrometry to determine the three-dimensional structure of biomolecular complexes. To achieve this goal, we will extend the Inferential Structure Determination (ISD) approach that has originally been developed for the calculation of single-chain protein structures from solution NMR data.











Contact

Spokesperson
Prof. Dr. Ralf Ficner mail
Telfon: +49 (0)551-39-14072
Fax: +49 (0)551-39-14082

SFB860 Administration
Contact email: mail
Susanne van Beckum mail
Tel.: +49 (0)551-39-10972
Fax: +49 (0)551-39-14082
SFB860 Georg-August-Universität Göttingen

Abtl. Molekulare Strukturbiologie
Justus-von-Liebig-Weg 11
37077 Göttingen