Archaeal membrane protein complexes (Werner Kühlbrandt)

Archaea form a separate kingdom of life between bacteria and eukaryotes. Archaea contain many unique protein assemblies and offer fascinating insights into an exotic, largely unknown macromolecular universe that we are exploring by cryoEM and cryoET.

Virus-induced pyramids Some viruses that infect archaea (archaeophages) induce the formation of large, 7-fold pyramid structures in the membrane of their archaeal hosts. The pyramids penetrate the protective S-layer from the inside and open in response to an unknown signal, creating ~1000 Å windows that allow the mature virus to escape. We use cryoET and sub-tomogram averaging to elucidate this unusual structure, and have expressed and crystallized the 10 kDa membrane protein that assembles into the pyramids. Figure 15A shows a tomographic slice through a virus-infected Sulfolobus cell, and sub-tomogram averages of the 7-fold pyramids (Figure 15B) (Daum et al., PNAS 2014).


Figure 15. Archaeal membrane protein assemblies. (A, B) Tomographic volumes of 7-fold pyramids in cells of the archaeon Sulfolobus islandicus infected by the archaeophage SIRV2. (C,D) Sub-tomogram average of 7-fold virus-induced pyramids in the Sulfolobus membrane. From (Daum et al., PNAS 2014).

Contact:

Max Planck Institute of Biophysics

Prof. Dr. Werner Kühlbrandt, Director
Department of Structural Biology
Secretary: Monika Hobrack

Phone: +49 (0) 69 6303-3001
Fax: +49 (0) 69 6303-3002
E-mail: monika.hobrack(at)biophys.mpg.de