Download MendeleyCryo-EM structure of the botulinum neurotoxin A/SV2B complex and its implications for translocation.
Khanppnavar, B., Leka, O., Pal, S.K., Korkhov, V.M., Kammerer, R.A.(2025) Nat Commun 16: 1224-1224
- PubMed: 39934119
- DOI: https://doi.org/10.1038/s41467-025-56304-z
- Primary Citation of Related Structures:
9F1R, 9F25, 9F2B, 9F2J, 9F2Y, 9F3C - PubMed Abstract:
Botulinum neurotoxin A1 (BoNT/A1) belongs to the most potent toxins and is used as a major therapeutic agent. Neurotoxin conformation is crucial for its translocation to the neuronal cytosol, a key process for intoxication that is only poorly understood. To gain molecular insights into the steps preceding toxin translocation, we determine cryo-EM structures of BoNT/A1 alone and in complex with its receptor synaptic vesicle glycoprotein 2B (SV2B). In solution, BoNT/A1 adopts a unique, semi-closed conformation. The toxin changes its structure into an open state upon receptor binding with the translocation domain (H N ) and the catalytic domain (LC) remote from the membrane, suggesting translocation incompatibility. Under acidic pH conditions, where translocation is initiated, receptor-bound BoNT/A1 switches back into a semi-closed conformation. This conformation brings the LC and H N close to the membrane, suggesting that a translocation-competent state of the toxin is required for successful LC transport into the neuronal cytosol.
Organizational Affiliation:
PSI Center for Life Sciences, Villigen, Switzerland.
