APOBEC3G is a single-strand DNA cytosine deaminase capable of blocking retrovirus and retrotransposon replication. APOBEC3G has two conserved zinc-coordinating motifs but only one is required for catalysis. Here, deletion analyses revealed that the minimal catalytic domain consists of residues 198-384. Size exclusion assays indicated that this protein is monomeric. Many (31/69) alanine substitution derivatives of APOBEC3G198-384 retained significant to full levels of activity. These data corroborated an APOBEC2-based structural model for the catalytic domain of APOBEC3G indicating that most non-essential residues are solvent accessible and most essential residues cluster within the protein core.
Bibliographical noteFunding Information:
This work was supported by NIH Grants AI064046 (RSH) and AI073167 (HM) and by the University of Minnesota’s Leukemia Research Fund (RSH) and Grant-in-Aid Program (HM). R.S.H. is a Searle Scholar and a University of Minnesota McKnight Land Grant Assistant Professor. We thank A. Briggs, P. Gross and Y. Sham for technical assistance, Harris and Matsuo laboratory members for helpful discussions and the University of Minnesota AGAC and SCI for DNA sequencing and computational resources, respectively.
- DNA cytosine deamination
- DNA editing