Hypermutation by intersegmental transfer of APOBEC3G cytidine deaminase

APOBEC3G is a cytidine deaminase that can be incorporated into HIV-1 virions and process the viral genome upon cell infection, leading to viral hypermutation and inactivation. APOBEC3G's activities are counteracted by viral protein Vif. Using a sensitive enzymatic assay, low levels of APOBEC3G can be detected associated to Vif(+) virions. Furthermore, the authors show that APOBEC3G functions in a distributive manner and causes dispersed hypermutation via intersegmental transfer.