Nanostructures of APOBEC3G support a hierarchical assembly model of high molecular mass ribonucleoprotein particles from dimeric subunits.

ABSTRACT: Human APOBEC3G (hA3G) is a cytidine deaminase that restricts human immunodeficiency virus (HIV)-1 infection in a vif (the virion infectivity factor from HIV)-dependent manner. hA3G from HIV-permissive activated CD4+ T-cells exists as an inactive, high molecular mass (HMM) complex that can be transformed in vitro into an active, low molecular mass (LMM) variant comparable with that of HIV-non-permissive CD4+ T-cells. Here we present low resolution structures of hA3G in HMM and LMM forms determined by small angle x-ray scattering and advanced shape reconstruction methods. The results show that LMM particles have an extended shape, dissimilar to known cytidine deaminases, featuring novel tail-to-tail dimerization. Shape analysis of LMM and HMM structures revealed how symmetric association of

SUBMITTER: Wedekind JE 

PROVIDER: S-EPMC1847398 | biostudies-literature | 2006 Dec

REPOSITORIES: biostudies-literature