Hiv env proteins

<StructureSection load='3dnn' size='450' side='right' caption='Structure of HMG-CoA reductase (PDB entry [[1dq8]])' scene=''>

== Introduction ==

Glycoprotein 120 (gp120) is a surface protein that is expressed on the viral envelope of Human Immunodeficiency Virus (HIV). HIV infects human cells with cell surface receptor CD4. Infection of the cell is initiated by the binding of CD4 by envelope glycoproteins (Env) on HIV. Env is a heterodimer consisting of gp120 and gp41 and forms trimers on the surface of the viral membrane. The protein structure shown on the right is the gp120 portion of Env in its unbound trimer state. <ref>PMID: 18668044</ref>

</StructureSection>