HIV GP120 bound to CD4 antigen

Hiv-1 Gp120 Envelope Glycoprotein Complexed With CD4 Antigen

Now let's look at the structure of the gp120 of HIV. In this image the alpha helices are shown in red and the beta sheets in yellow-orange. The connecting segments are in gray. The glycoprotein shown in the image below is not complete since the N-terminus is missing up to residue 89 . The protein chain is folded into an inner and an outer domain which are linked by an anti-parallel four-stranded bridging sheet . This microdomain is also in contact with the CD4 molecule and the chemokine . To see this rotate the molecule using the mouse or here [on On Off Zoom out Zoom 200% Zoom 300% ]. Also found extending from the outer domain is a region consisting of the beta 15 sheet and the alpha 3 helix . This is also in contact with the CD4 molecule.

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The paper in Nature describing this is here - Protein database information is here - Get Chime here - Go back to the previous page here

HIV enveloped glycoprotein, Gp120
Structure:
alpha helix: red
beta sheet: orange

Wireframe
Backbone
Space Fill
Ribbons
Strands

Terminii

N terminus- threonine 90 (yellow)

C terminus - glutamic acid 492 (red)

alpha helix - inner domain

alpha helix - outer domain

beta sheets - inner domain

beta sheets - outer domain

bridging sheet

alpha 3 helix and beta 15 sheet

Carbohydrate chains
on HIV Gp120
Best seen with gp120 spacefill
(brown)

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Show CD4 antigen

Backbone
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Ribbons
Strands

Show chemokine binding site

lys121 Space Fill
arg419 Space Fill
lys 421 Space Fill
gln422 Space Fill
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Hydrophobic interactions of viral gp120 to cellular CD4

Gp120 residues: Space Fill
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