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PDBsum entry 1ar7
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Contents |
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283 a.a.
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268 a.a.
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235 a.a.
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60 a.a.
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* Residue conservation analysis
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References listed in PDB file
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Key reference
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Title
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Structural studies of poliovirus mutants that overcome receptor defects.
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Authors
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M.W.Wien,
S.Curry,
D.J.Filman,
J.M.Hogle.
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Ref.
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Nat Struct Biol, 1997,
4,
666-674.
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PubMed id
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Abstract
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In order to better understand the process of cell entry for non-enveloped
viruses, we have solved the crystal structures of five poliovirus mutants which
can infect cells expressing mutant poliovirus receptors. Four of these
structures have been solved from frozen crystals using cryocrystallographic data
collection methods. The mutations have a range of structural consequences, from
small local perturbations to significant loop rearrangements. All of the mutant
viruses are more labile to conversion to an apparent cell entry intermediate,
suggesting that these mutant viruses could compensate for the suboptimal
receptors by lowering the thermal energy required to undergo the
receptor-mediated conformational change.
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Secondary reference #1
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Title
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A pseudo-Cell based approach to efficient crystallographic refinement of viruses.
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Authors
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D.H.Jacobson,
J.M.Hogle,
D.J.Filman.
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Ref.
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Acta Crystallogr D Biol Crystallogr, 1996,
52,
693-711.
[DOI no: ]
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PubMed id
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Figure 1.
Fig. 1. A flow diagram summarizing the
refinement of atomic positional para-
meters in the XX 12 procedure. Detailed
descriptions of most of the steps are
given in the text. At the outset, electron-
density values from a current version of
the
WEDGE MAP
(upper left corner),
obtained from the phase-constraint pro-
cedure, are expanded using icosahedral
operators to fill the protomer-box
volume, filtered, and Fourier trans-
formed to create a set of reference
structure factors
(Fob~o)
to be used as
complex-valued standards for the
refinement. Each refinement cycle
begins with the most current copy of
the atomic model (upper right corner).
Expansion of these atom coordinates,
using icosahedral operators, to fill the
protomer-box volume, leads to a set of
model-based structure factors
(F¢,,l~),
which are scaled to the reference
standards using resolution-dependent
bin scales. The
VECTOR DIFFERENCE
MAP
(bottom center) is obtained by
Fourier transformation of the scaled
differences between the two sets of
structure factors. One set of
ATOMIC
SHIFTS
(lower right corner) is obtained
from the difference map by interpola-
tion at the atom positions. Simultan-
eously, a second set of
ATOMIC
SHIFTS
based solely on
STEREO-
CHEMISTRY
(center) is obtained by
running the
X-PLOR
package, given
knowledge of the unit cell and of
icosahedral and crystallographic sym-
metry operators. Each cycle concludes
with the
TARGET
routine (right center),
which scales the two sets of shifts
appropriately and updates the
ATOMIC
MODEL
(upper right) with an improved
set of coordinates.
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Figure 6.
Fig. 6. Stereoviews of portions of the V510 atomic model, illustrating
changes caused by refinement. (a) Met3149, which exhibits
the single largest atomic difference (0.45 A) caused by applying
full-cell
X-PLOR
refinement (thick lines) to a model previously
refined using XX12 (thin lines). Both conformations represent
very similar interpretations of the electron density. (b) The
conformation adopted by Va11244 after successive refinement
steps. The thin, intermediate, and thick lines, respectively, show
the model after an initial refinement with XX12, a subsequent
refinement with full-cell
X-PLOR,
and a final refinement with
XX12. Observe that all three refinement steps have tended to move
the carbonyl O atoms in the same direction, towards the electron-
density bulge at the left of the panel.
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The above figures are
reproduced from the cited reference
with permission from the IUCr
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Secondary reference #2
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Title
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Three-Dimensional structure of poliovirus at 2.9 a resolution.
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Authors
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J.M.Hogle,
M.Chow,
D.J.Filman.
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Ref.
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Science, 1985,
229,
1358-1365.
[DOI no: ]
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PubMed id
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