HIV-1 is composed of two copies of single-stranded RNA enclosed by a conical capsid comprising the viral protein p24, typical of lentiviruses. As a component of the HIV-virus particle there are approximately 2000 molecules per virus particle, or at a molecule weight of 24 kDa, about 10^4 virus particles per picogram of p24. HIV gag (group-specific antigen): codes for the Gag polyprotein, which is processed during maturation to MA (matrix protein, p17), CA (capsid protein, p24), SP1 (spacer peptide 1, p2), NC (nucleocapsid protein, p7), SP2 (spacer peptide 2, p1) and p6. Alternative Names: Human Immunodeficiency Virus Type 1 Viral infectivity Factor IIIB Protein, HIV1 vif IIB, HIV1 vif IIIB protein, HIV-1 vif IIB protein, HIV-1 vif IIIB protein, HIV 1 vif IIB protein, HIV-1 Viral Infectivity Factor IIIB Protein, HIV 1 vif IIB, HIV-1 vif IIB