| Autor: |
Robert K. Y. Cheng, Mohamed Chami, Matilde Cardoso Trabuco, Stephan Schenck, Janine D. Brunner, Henning Stahlberg, Michael Hennig, Denis Bucher, Markus A. Seeger, Pascal Egloff, Nicolas Bocquet, Iwan Zimmermann, Mathieu Botte, Dongchun Ni |
| Rok vydání: |
2021 |
| Předmět: |
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| DOI: |
10.1101/2021.03.23.436624 |
| Popis: |
Lipopolysaccharides (LPS) are major constituents of the extracellular leaflet in the bacterial outer membrane and form an effective physical barrier for environmental threats and for antibiotics in Gram-negative bacteria 1. The last step of LPS insertion via the Lpt pathway is mediated by the LptD/E protein complex 2. Despite detailed insights from X-ray crystallography into the architecture of LptDE transporter complexes 3–5, no structure of a laterally open LptD transporter has been described, a transient state that occurs during LPS release 6. To facilitate the acquisition of hitherto unknown conformations we subjected LptDE of N. gonorrhoeae to cryo-EM analyses. In complex with newly designed rigid chaperones derived from nanobodies (Pro-Macrobodies, PMbs) we obtained a map of a partially opened LptDE transporter at 3.4 Å resolution and in addition we captured a laterally fully opened LptDE complex from a subset of particles. Our work offers new insights into the mechanism of LPS insertion, provides a structural framework for the development of antibiotics targeting LptD and describes a novel, highly rigid and widely applicable chaperone scaffold to enable structural biology of challenging protein targets. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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