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PDBsum entry 1zv8
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Viral protein
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PDB id
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1zv8
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Contents |
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49 a.a.
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27 a.a.
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46 a.a.
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29 a.a.
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30 a.a.
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50 a.a.
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34 a.a.
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34 a.a.
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References listed in PDB file
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Key reference
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Title
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Structures and polymorphic interactions of two heptad-Repeat regions of the sars virus s2 protein.
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Authors
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Y.Deng,
J.Liu,
Q.Zheng,
W.Yong,
M.Lu.
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Ref.
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Structure, 2006,
14,
889-899.
[DOI no: ]
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PubMed id
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Abstract
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Entry of SARS coronavirus into its target cell requires large-scale structural
transitions in the viral spike (S) glycoprotein in order to induce fusion of the
virus and cell membranes. Here we describe the identification and crystal
structures of four distinct alpha-helical domains derived from the highly
conserved heptad-repeat (HR) regions of the S2 fusion subunit. The four domains
are an antiparallel four-stranded coiled coil, a parallel trimeric coiled coil,
a four-helix bundle, and a six-helix bundle that is likely the final fusogenic
form of the protein. When considered together, the structural and thermodynamic
features of the four domains suggest a possible mechanism whereby the HR
regions, initially sequestered in the native S glycoprotein spike, are released
and refold sequentially to promote membrane fusion. Our results provide a
structural framework for understanding the control of membrane fusion and should
guide efforts to intervene in the SARS coronavirus entry process.
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Figure 3.
Figure 3. Crystal Structure of the C44 Tetramer
(A)
Lateral view of the C44 tetramer. Yellow van der Waals surfaces
identify residues at the a positions, red surfaces identify
residues at the d positions, and light-blue surfaces identify
residues at the g positions. The N termini of helices A and B
are indicated.
(B) Axial view of the C44 tetramer. The red
van der Waals surfaces of the Ile1154(d) and Leu1182(d) side
chains are depicted.
(C) Cross-section of the tetramer in
the Ile1161(d) layer. The 1.70 Å 2F[o] − F[c] electron
density map (contoured at 1.2σ) is shown with the refined
molecular model.
(D) Helical wheel representation of
residues 1153–1185 of the C44 tetramer. Heptad-repeat
positions are labeled a–g. The C44 helices interact through a
previously uncharacterized type of packing interaction between
the a, d, and g side chains (colored green). Figure 3.
Crystal Structure of the C44 Tetramer(A) Lateral view of the C44
tetramer. Yellow van der Waals surfaces identify residues at the
a positions, red surfaces identify residues at the d positions,
and light-blue surfaces identify residues at the g positions.
The N termini of helices A and B are indicated.(B) Axial view of
the C44 tetramer. The red van der Waals surfaces of the
Ile1154(d) and Leu1182(d) side chains are depicted.(C)
Cross-section of the tetramer in the Ile1161(d) layer. The 1.70
Å 2F[o] − F[c] electron density map (contoured at 1.2σ)
is shown with the refined molecular model.(D) Helical wheel
representation of residues 1153–1185 of the C44 tetramer.
Heptad-repeat positions are labeled a–g. The C44 helices
interact through a previously uncharacterized type of packing
interaction between the a, d, and g side chains (colored green).
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Figure 5.
Figure 5. Crystal Structure of the N50/C36 Complex
(A)
Ribbon diagram of the N50/C36 complex. The N termini of the N50
(red) and C36 (green) chains are indicated.
(B) Conserved
grooves on the surface of the N50 coiled-coil trimer. The C36
peptides drawn as an atomic model are shown against a surface
representation of the N50 trimer. The view is in approximately
the same orientation as in (A). The solvent-accessible surface
is colored according to the local electrostatic potential;
colors range from dark blue, representing the most positive
area, to deep red, representing the most negative area.
(C)
Cross-section of the N50/C36 complex in the Thr923 layer
showing “x-like” packing of side chains that project
simultaneously toward the 3-fold axis. The 2F[o] − F[c]
electron density map contoured at 1.5σ is shown with the
refined molecular model.
(D) Cross-section of the N50/C36
complex in the Ser919–Leu920 layer showing “y-like”
packing of alternating small and large side chains in a
hexagonal arrangement. Figure 5. Crystal Structure of the
N50/C36 Complex(A) Ribbon diagram of the N50/C36 complex. The N
termini of the N50 (red) and C36 (green) chains are
indicated.(B) Conserved grooves on the surface of the N50
coiled-coil trimer. The C36 peptides drawn as an atomic model
are shown against a surface representation of the N50 trimer.
The view is in approximately the same orientation as in (A). The
solvent-accessible surface is colored according to the local
electrostatic potential; colors range from dark blue,
representing the most positive area, to deep red, representing
the most negative area.(C) Cross-section of the N50/C36 complex
in the Thr923 layer showing “x-like” packing of side chains
that project simultaneously toward the 3-fold axis. The 2F[o]
− F[c] electron density map contoured at 1.5σ is shown with
the refined molecular model.(D) Cross-section of the N50/C36
complex in the Ser919–Leu920 layer showing “y-like”
packing of alternating small and large side chains in a
hexagonal arrangement.
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The above figures are
reprinted
by permission from Cell Press:
Structure
(2006,
14,
889-899)
copyright 2006.
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