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PDBsum entry 1df4
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Viral protein
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PDB id
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1df4
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Contents |
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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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Interactions between HIV-1 gp41 core and detergents and their implications for membrane fusion.
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Authors
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W.Shu,
H.Ji,
M.Lu.
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Ref.
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J Biol Chem, 2000,
275,
1839-1845.
[DOI no: ]
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PubMed id
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Abstract
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The gp41 envelope protein mediates entry of human immunodeficiency virus type 1
(HIV-1) into the cell by promoting membrane fusion. The crystal structure of a
gp41 ectodomain core in its fusion-active state is a six-helix bundle in which a
N-terminal trimeric coiled coil is surrounded by three C-terminal outer helices
in an antiparallel orientation. Here we demonstrate that the N34(L6)C28 model of
the gp41 core is stabilized by interaction with the ionic detergent sodium
dodecyl sulfate (SDS) or the nonionic detergent n-octyl-beta-D-glucopyranoside
(betaOG). The high resolution x-ray structures of N34(L6)C28 crystallized from
two different detergent micellar media reveal a six-helix bundle conformation
very similar to that of the molecule in water. Moreover, N34(L6)C28 adopts a
highly alpha-helical conformation in lipid vesicles. Taken together, these
results suggest that the six-helix bundle of the gp41 core displays substantial
affinity for lipid bilayers rather than unfolding in the membrane environment.
This characteristic may be important for formation of the fusion-active gp41
core structure and close apposition of the viral and cellular membranes for
fusion.
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Figure 1.
Fig. 1. HIV-1 gp41 core structure. A schematic diagram of
gp41 showing the important functional regions of the ectodomain.
The amino acid sequences of the N34 and C28 segments are shown.
The N34(L6)C28 model of the gp41 core consists of N34 and C28
plus a linker of six hydrophilic residues. The disulfide bond
and four potential N-glycosylation sites are depicted. The
residues are numbered according to their position in gp160.
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Figure 7.
Fig. 7. Stereo view of the superposition of residues
564-571 of N34 and 628-633 of C28 in the N34(L6)C28 structures
in water (red), SDS (green), and  OG (white),
showing a cross-section of helix packing near the conserved
hydrophobic cavity in the gp41 core. Figure was generated with
the program SETOR (56).
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The above figures are
reprinted
by permission from the ASBMB:
J Biol Chem
(2000,
275,
1839-1845)
copyright 2000.
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