Download Structure of amphiphysin. The concave face is positively charged

Concave
(lipid-interacting)
face
Dynamin-induced tubulation of
lipid bilayers.
Top panels at right - EM of lipid
vesicles (b) before and (d) after
addition of dynamin. Note the
extensive formation of tubules in
(d).
Bottom panels at right - Additional
EM images of dynamin-induced
lipid tubules. Magnify the image
shown in panel (a) to see more
clearly the spiral ʻwrappingʼ of
oligomerized dynamin around the
lipdi tubule, as shown in the
cartoon below (though in the
image shown in (a) there is less
space between adjacent ʻwraps.ʼ
Dynamin
GTP-dependent
oligomerization
Lipids distorted
Structure of amphiphysin. The concave
face is positively charged and interacts with
the lipid bilayer (cytoplasmic face). Because
of its geometry, this face of the protein
interacts optimally with bilayers when they
are curved into the shape of a cylinder with
a diameter of 22 nm (220 Angstroms).
Amphiphysin, acting together with
endophilin and dynamin, deforms the membrane in the ʻneckʼ region to form a narrow
neck with roughly this diameter.