File:N-terminal catalytic domain.upright=alt= Figure 1: “Structure model of the N-terminal catalytic deaminase domain of<unk> . Zinc-coordinating residues are indicated by circles, α-helices are in yellow, and β-strands are in pink. The position of residue D128 is indicated in the predicted loop between β4 and α3.”<unk>  has a symmetric structure, resulting in 2 homologous catalytic domains, the N-terminal (CD1) and C-terminal (CD2) domains, each of which contains a coordination site. Each domain also has the typical His/Cys-X-Glu-X23–28-Pro-Cys-X2-Cys motif for cytidine deaminases. However, unlike the typical cytidine deaminases,<unk>  contains a unique alpha helix between two beta sheets in the catalytic domain that could be a cofactor binding site. (Figure 1) CD2 is catalytically active and vital for deamination and motif specificity. CD1 is catalytically inactive, but very important for binding to DNA and RNA and is key to defining the 5’->3’ processivity of<unk>  deamination. CD2 has no deaminase activity without the presence of CD1. Native<unk>  is composed of monomers, dimers, trimers, tetramers, and higher order oligomers. While it is thought that<unk>  functions as a dimer, it is possible that it actually functions as a mix of monomers and oligomers. The D128 amino acid residue, which lies within CD1 (Figure 1), appears to be particularly important for<unk>  interactions with Vif because a D128K point mutation prevents Vif-dependent depletion of<unk> . Additionally, amino acids 128–130 on<unk>  form a negatively charged motif that is critical for interactions with Vif and the formation of<unk> -Vif complexes. Furthermore, residues 124-127 are important for encapsidation of<unk>  into HIV-1 virions and the resulting antiretroviral activity.
APOBEC3G
GP1BA
GP1BB
PHKA2
PIM2
TOFI
CoWIN
STAR*D