Thursday, 26 September 2019 at 11:00 | Large Operon, EMBL Heidelberg
Wolfgang Baumeister | Max Planck Institute of Biochemistry (DE)
Hosts: Julia Mahamid, Martin Beck, Structural and Computational Biology Unit
THE MOLECULAR MACHINERY OF INTRACELLULAR PROTEIN DEGRADATION: STRUCTURAL STUDIES EX SITU AND IN SITU
The 26S proteasome operates at the executive end of the ubiquitin-proteasome pathway for the controlled degradation of intracellular proteins. The 2.5 MDa complex comprises two subcomplexes: the 20S core where proteolysis takes place and one or two regulatory particles which prepare substrates for degradation. Whereas the structure of its 20S core particle has been determined by X-ray crystallography more than two decades ago, the structure of the regulatory particle, which recruits substrates, unfolds them, and assists in their translocation into the core particle remained elusive for a long time. Only in recent years has its structure been determined to high resolution using cryo-electron microscopy single particle analysis.
Cryo-electron tomography allows to perform structural studies of macromolecular and supramolecular structures in situ, i.e. in their functional cellular environments. We used this method to study the 26S proteasome in a number of cellular settings revealing their precise location, assembly and activity status as well as their interactions with other molecular players of the cellular degradation machinery.
Wolfgang Baumeister obtained his PhD from the University of Düsseldorf in 1973. He spent time as a Heisenberg Fellow at Cavendish Laboratory in Cambridge. In 1982 he joined the Max Planck Institute of Biochemistry in Martinsried as a group leader; since 1988 he is Director and Head of the Department of Structural Biology. He is also an Honorary Professor in the faculties of Physics and Chemistry of the Technical University, Munich.
General research statement
Wolfgang Baumeister pioneered the development of cryo-electron tomography for structural studies of macromolecular and supramolecular structures in their cellular environment. He is particularly interested in the molecular machinery of intracellular protein degradation.