In situ structural analysis of the Yersinia enterocolitica injectisome
Mikhail Kudryashev,
Marco Stenta,
Stefan Schmelz,
Marlise Amstutz,
Ulrich Wiesand,
Daniel Castaño-Díez,
Matteo T Degiacomi,
Stefan Münnich,
Christopher KE Bleck,
Julia Kowal,
Andreas Diepold,
Dirk W Heinz,
Matteo Dal Peraro,
Guy R Cornelis,
Henning Stahlberg
Affiliations
Mikhail Kudryashev
Center for Cellular Imaging and NanoAnalytics (C-CINA), Biozentrum, University of Basel, Basel, Switzerland
Marco Stenta
Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
Stefan Schmelz
Division of Structural Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
Marlise Amstutz
Focal Area Infection Biology, Biozentrum, University Basel, Basel, Switzerland
Ulrich Wiesand
Division of Structural Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany; Focal Area Infection Biology, Biozentrum, University Basel, Basel, Switzerland
Daniel Castaño-Díez
Center for Cellular Imaging and NanoAnalytics (C-CINA), Biozentrum, University of Basel, Basel, Switzerland
Matteo T Degiacomi
Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
Stefan Münnich
Division of Structural Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
Christopher KE Bleck
Center for Cellular Imaging and NanoAnalytics (C-CINA), Biozentrum, University of Basel, Basel, Switzerland
Julia Kowal
Center for Cellular Imaging and NanoAnalytics (C-CINA), Biozentrum, University of Basel, Basel, Switzerland
Andreas Diepold
Focal Area Infection Biology, Biozentrum, University Basel, Basel, Switzerland
Dirk W Heinz
Division of Structural Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
Matteo Dal Peraro
Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland; Swiss Institute of Bioinformatics (SIB), Lausanne, Switzerland
Guy R Cornelis
Focal Area Infection Biology, Biozentrum, University Basel, Basel, Switzerland
Henning Stahlberg
Center for Cellular Imaging and NanoAnalytics (C-CINA), Biozentrum, University of Basel, Basel, Switzerland
Injectisomes are multi-protein transmembrane machines allowing pathogenic bacteria to inject effector proteins into eukaryotic host cells, a process called type III secretion. Here we present the first three-dimensional structure of Yersinia enterocolitica and Shigella flexneri injectisomes in situ and the first structural analysis of the Yersinia injectisome. Unexpectedly, basal bodies of injectisomes inside the bacterial cells showed length variations of 20%. The in situ structures of the Y. enterocolitica and S. flexneri injectisomes had similar dimensions and were significantly longer than the isolated structures of related injectisomes. The crystal structure of the inner membrane injectisome component YscD appeared elongated compared to a homologous protein, and molecular dynamics simulations documented its elongation elasticity. The ring-shaped secretin YscC at the outer membrane was stretched by 30–40% in situ, compared to its isolated liposome-embedded conformation. We suggest that elasticity is critical for some two-membrane spanning protein complexes to cope with variations in the intermembrane distance.
