In:
Journal of General Physiology, Rockefeller University Press, Vol. 148, No. 4 ( 2016-10-01), p. 313-324
Abstract:
Anthrax toxin comprises three soluble proteins: protective antigen (PA), lethal factor (LF), and edema factor (EF). PA must be cleaved by host proteases before it oligomerizes and forms a prepore, to which LF and EF bind. After endocytosis of this tripartite complex, the prepore transforms into a narrow transmembrane pore that delivers unfolded LF and EF into the host cytosol. Here, we find that translocation of multiple 90-kD LF molecules is rapid and efficient. To probe the molecular basis of this translocation, we calculated a three-dimensional map of the fully loaded (PA63)7–(LF)3 prepore complex by cryo–electron microscopy (cryo-EM). The map shows three LFs bound in a similar way to one another, via their N-terminal domains, to the surface of the PA heptamer. The model also reveals contacts between the N- and C-terminal domains of adjacent LF molecules. We propose that this molecular arrangement plays an important role in the maintenance of translocation efficiency through the narrow PA pore.
Type of Medium:
Online Resource
ISSN:
0022-1295
,
1540-7748
DOI:
10.1085/jgp.201611617
Language:
English
Publisher:
Rockefeller University Press
Publication Date:
2016
detail.hit.zdb_id:
1477246-2
SSG:
12
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