Fig. 19 Β-tubulin entropic bristle domain (EBD) regulated microtubule
disassembly. A) Side view of a single β-tubuiin monomer (purple) of radius b,
with an EBD (red) of characteristicsize ρ. B) Cross-section of a microtubule cut
along a row ofβ-tubulins. Shading (red) indicates regions of overlap where EBDs
sterically hinder one another. Radial expansion of the aggregate releases EBDs
from confinement at the expense of lateral bonds. C) Side view of a pair of
protofilaments oriented as in a microtubule. For simplicity, the α-tubulin
monomers (white) are drawn contacting the β-tubulin monomers (purple)
equidistant on either side of the EBD (red). Note the slight overlap of the EBDs
with the α-tubulin spheres. A radius of curvature Rpf eliminates the overlap.
Modified from Deborah Fygenson (2001)
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