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Name
of Journal |
Nature,
424: 643-650 (2003) |
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Author |
Yonekura K, Maki-Yonekura
S, Namba K. |
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Title of Article |
Complete atomic model of
the bacterial flagellar filament by electron cryomicroscopy. |
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Laboratory
HP |
http://www.fbs.osaka-u.ac.jp/labo/09a.html |
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Summary |
The bacterial flagellar
filament is a helical propeller for bacterial locomotion.
Electron cryomicroscopy and image analysis visualized its
atomic structure and unveiled the precise switching mechanism
of this switchable helical propeller at nano-scale.
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PubMed
Link |
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?
cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12904785 |
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Email
for reprint request |
Keiichi Namba:  |
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Description |
The
bacterial flagellar filament is a helical propeller for
bacterial
locomotion.
It is a helical assembly of a single protein, flagellin,
and its tubular structure is formed by 11 protofilaments
in two distinct conformations, L- and R-type, for supercoiling.
The X-ray crystal structure of a flagellin fragment
lacking about 100 terminal residues revealed the protofilament
structure, but the full filament structure is still
essential
for understanding
the mechanism of supercoiling and polymerization. Here
we report a complete atomic model of the R-type filament
by
electron cryomicroscopy. A density map obtained from
image data up to 4 Å resolution shows the
feature of -helical backbone and some large side chains.
The
atomic model built on the map reveals intricate molecular
packing
and an -helical coiled coil formed by the terminal
chains in the inner core of the filament, with its intersubunit
hydrophobic interactions having an important role in
stabilizing the filament. |
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Click the image below for
viewing a larger image.
Figure 1: Computer graphic representation of
the assembly process of the bacterial flagellum and a swimming
bacterium
with a rotating
bundle of the helical flagellar filaments behind the cell body.
The diameter of the filament is 20 nm and the length is about
10 mm. |
Figure2: Ca backbone model of the atomic
structure of the flagellar filament. Side views showing the
inner side
(left) and outer surface (right). The amino acid sequence of
each flagellin subunit is color-coded from blue for the N-terminus
to red for the C-terminus.
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Moving Images
Collection
(JST Website)
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| For details, please download a movie(34 min.)
here.
*Please be aware of the file size.
Medium
size:105MB
QuickTime movie:320x240 pixels
Large size: 288MB MPEG-4 movie:
640x480 pixels
A Rotary NanoMachine
~Understanding the Structure and Dynamics of Bacterial Flagella~
Protonic NanoMachine Project, ERATO, Japan Science and Technology
Corporation
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