Atomic force microscopy studies provide direct evidence for dimerization of the HIV restriction factor APOBEC3G.

ABSTRACT: APOBEC3G (A3G) is an antiviral protein that binds RNA and single-stranded DNA (ssDNA). The oligomerization state of A3G is likely to be influenced by these nucleic acid interactions. We applied the power of nanoimaging atomic force microscopy technology to characterize the role of ssDNA in A3G oligomerization. We used recombinant human A3G prepared from HEK-293 cells and specially designed DNA substrates that enable free A3G to be distinguished unambiguously from DNA-bound protein complexes. This DNA substrate can be likened to a molecular ruler because it consists of a 235-bp double-stranded DNA visual tag spliced to a 69-nucleotide ssDNA substrate. This hybrid substrate enabled us to use volume measurements to determine A3G stoichiometry in both free and ssDNA-bound states. We observed t

SUBMITTER: Shlyakhtenko LS 

PROVIDER: S-EPMC3030345 | biostudies-literature | 2011 Feb

REPOSITORIES: biostudies-literature