6RW9

Cryo-EM structure of Morganella morganii TcdA4

Summary for 6RW9

• Entry DOI: 10.2210/pdb6rw9/pdb
• Related: 6RW6 6RW8
• EMDB information: 10035
• Descriptor: Insecticidal toxin protein TcdA4 (1 entity in total)
• Functional Keywords: toxin, membrane permeation, translocation, complex
• Biological source: Morganella morganii subsp. morganii
• Total number of polymer chains: 5
• Total formula weight: 1378291.56

Authors

Roderer, D.,Leidreiter, F.,Gatsogiannis, C.,Meusch, D.,Benz, R.,Raunser, S. (deposition date: 2019-06-04, release date: 2019-10-23, Last modification date: 2024-05-22)

Primary citation

Leidreiter, F.,Roderer, D.,Meusch, D.,Gatsogiannis, C.,Benz, R.,Raunser, S.
Common architecture of Tc toxins from human and insect pathogenic bacteria.
Sci Adv, 5:eaax6497-eaax6497, 2019

PubMed Abstract: Tc toxins use a syringe-like mechanism to penetrate the membrane and translocate toxic enzymes into the host cytosol. They are composed of three components: TcA, TcB, and TcC. Low-resolution structures of TcAs from different bacteria suggest a considerable difference in their architecture and possibly in their mechanism of action. Here, we present high-resolution structures of five TcAs from insect and human pathogens, which show a similar overall composition and domain organization. Essential structural features, including a trefoil protein knot, are present in all TcAs, suggesting a common mechanism of action. All TcAs form functional pores and can be combined with TcB-TcC subunits from other species to form active chimeric holotoxins. We identified a conserved ionic pair that stabilizes the shell, likely operating as a strong latch that only springs open after destabilization of other regions. Our results provide new insights into the architecture and mechanism of the Tc toxin family.

PubMed: 31663026
DOI: 10.1126/sciadv.aax6497

Experimental method

ELECTRON MICROSCOPY (3.27 Å)