Molecular architecture of botulinum neurotoxin E revealed by single particle electron microscopy.
Clostridial botulinum neurotoxin (BoNT) causes a neuroparalytic condition recognized as botulism by arresting synaptic vesicle exocytosis. Although the crystal structures of full-length BoNT/A and BoNT/B holotoxins are known, the molecular architecture of the five other serotypes remains elusive. Here, we present the structures of BoNT/A and BoNT/E using single particle electron microscopy. Labeling of the particles with three different monoclonal antibodies raised against BoNT/E revealed the positions of their epitopes in the electron microscopy structure, thereby identifying the three hallmark domains of BoNT (protease, translocation, and receptor binding). Correspondingly, these antibodies selectively inhibit BoNT translocation activity as detected using a single molecule assay. The global structure of BoNT/E is strikingly different from that of BoNT/A despite strong sequence similarity. We postulate that the unique architecture of functionally conserved modules underlies the distinguishing attributes of BoNT/E and contributes to differences with BoNT/A.
Fischer
Audrey
A
Section of Neurobiology, Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093-0366, USA.
Garcia-Rodriguez
Consuelo
C
Geren
Isin
I
Lou
Jianlong
J
Marks
James D
JD
Nakagawa
Terunaga
T
Montal
Mauricio
M
D000911:Antibodies, Monoclonal / Q000276:immunology; D001905:Botulinum Toxins / Q000737:chemistry* / Q000276:immunology; D004591:Electrophoresis, Polyacrylamide Gel; D008854:Microscopy, Electron / Q000379:methods*; D011487:Protein Conformation
D000911:Antibodies, Monoclonal; D001905:Botulinum Toxins; C096326:botulinum toxin type E