The products of the Gag polyproteins of infectious retroviruses perform highly complex orchestrated tasks during the assembly, budding, maturation, and infection stages of the viral replication cycle. During viral assembly, the proteins form membrane associations and self-associations that ultimately result in budding of an immature virion from the infected cell. Gag precursors also function during viral assembly to selectively bind and package two plus strands of genomic RNA. Endogenous Gag proteins may have kept, lost or modified their original function during evolution (By similarity).
Early post-infection, the reverse transcriptase converts the viral RNA genome into double-stranded viral DNA. The RNase H domain of the reverse transcriptase performs two functions. It degrades the RNA template and specifically removes the RNA primer from the RNA/DNA hybrid. Following nuclear import, the integrase catalyzes the insertion of the linear, double-stranded viral DNA into the host cell chromosome. Endogenous Pol proteins may have kept, lost or modified their original function during evolution (By similarity).
Subcellular locations: Cell membrane
Cytoplasmic membrane (in a transfection system).