The cryo-EM structure of the BoNT/Wo-NTNH complex reveals two immunoglobulin-like domains

0576863 - ÚOCHB 2025 RIV GB eng J - Journal Article
Kosenina, S. - Škerlová, Jana - Zhang, S. - Dong, M. - Stenmark, P.
The cryo-EM structure of the BoNT/Wo-NTNH complex reveals two immunoglobulin-like domains.
FEBS Journal. Roč. 291, č. 4 (2024), s. 676-689. ISSN 1742-464X. E-ISSN 1742-4658
R&D Projects: GA MŠMT(CZ) EF16_027/0008477
Institutional support: RVO:61388963
Keywords : BoNT-NTNH complex * botulinum neurotoxins * cryo-EM structure * Weissella oryzae
OECD category: Medicinal chemistry
Impact factor: 5.4, year: 2022
Method of publishing: Open access
https://doi.org/10.1111/febs.16964

The botulinum neurotoxin-like toxin from Weissella oryzae (BoNT/Wo) is one of the BoNT-like toxins recently identified outside of the Clostridium genus. We show that, like the canonical BoNTs, BoNT/Wo forms a complex with its non-toxic non-hemagglutinin (NTNH) partner, which in traditional BoNT serotypes protects the toxin from proteases and the acidic environment of the hosts' guts. We here report the cryo-EM structure of the 300 kDa BoNT/Wo-NTNH/Wo complex together with pH stability studies of the complex. The structure reveals molecular details of the toxin's interactions with its protective partner. The overall structural arrangement is similar to other reported BoNT-NTNH complexes, but NTNH/Wo uniquely contains two extra bacterial immunoglobulin-like (Big) domains on the C-terminus. Although the function of these Big domains is unknown, they are structurally most similar to bacterial proteins involved in adhesion to host cells. In addition, the BoNT/Wo protease domain contains an internal disulfide bond not seen in other BoNTs. Mass photometry analysis revealed that the BoNT/Wo-NTNH/Wo complex is stable under acidic conditions and may dissociate at neutral to basic pH. These findings established that BoNT/Wo-NTNH/Wo shares the general fold of canonical BoNT-NTNH complexes. The presence of unique structural features suggests that it may have an alternative mode of activation, translocation and recognition of host cells, raising interesting questions about the activity and the mechanism of action of BoNT/Wo as well as about its target environment, receptors and substrates.
Permanent Link: https://hdl.handle.net/11104/0346268


Research data: EMDB, PDB