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Structure of HIV virus:

  1. HIV virus measures 100 nm in diameter.
  2. It is spherical in shape covered by a lipid bilayer membrane
  3. Inside the outer lipid membrane is a cylindrical core that houses two copies of single stranded viral RNA which encode a series of structural, enzymatic and regulatory proteins that are needed for the effective completion of the viral life cycle.
  4. The viral membrane is host derived i.e.. it results from the budding from the cell surface.
  5. The surface glycoproteins which include:
    Gp160: Encoded by env (envelop) gene. It undergoes cleavage by the host enzymes after translation so as to form Gp120 and Gp41.
  6. The internal structural proteins are encoded by gag (group-specific antigen) gene.
  7. The other internal proteins are encoded by the pol (polymerase gene).
  8. The enzymes that participate in the integration and replication are given in the table below:

Name of enzyme


Reverse transcriptase

Copies the RNA genome into Double stranded DNA


Integrates the double stranded DNA into the host cell chromosome


Cleaves the pol and gag-encoded proteins

  1. The genome of HIV is diploid positive sense RNA
  2. It consists of 9749 nucleotides
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