HIV virus has :
Classification of HIV ( = HTLV III) 
Family – Retroviridae
Subfamily – Lentivirus
Genome – SS RNA positive sense.
• Virion contain lipoprotein envelope and nucleocapsid is icosahedral in shape.
• Characteristic feature of retrovirus is presence of reverse transcriptase enzyme.
– Viral RNA is transcribed by this enzyme first into SS DNA then to ds DNA which gets integrated with host cell.
– Thus in contrast to central dogma flow of information is RNA  →  DNA  →  RNA
Single  stranded  DNA
Single  stranded  RNA
Double  stranded  DNA
Double  stranded  RNA