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Complementary function of the two catalytic domains of APOBEC3G.
- Source :
-
Virology [Virology] 2005 Mar 15; Vol. 333 (2), pp. 374-86. - Publication Year :
- 2005
-
Abstract
- The HIV-1 viral accessory protein Vif prevents the encapsidation of the antiviral cellular cytidine deaminases APOBEC3F and APOBEC3G by inducing their proteasomal degradation. In the absence of Vif, APOBEC3G is encapsidated and blocks virus replication by deaminating cytosines of the viral cDNA. APOBEC3G encapsidation has been recently shown to depend on the viral nucleocapsid protein; however, the role of RNA remains unclear. Using APOBEC3G deletion and point mutants, we mapped the encapsidation determinant to the Zn(2+) coordination residues of the N-terminal catalytic domain (CD1). Notably, these residues were also required for RNA binding. Mutations in the two aromatic residues of CD1 but not CD2, which are conserved in cytidine deaminase core domains and are required for RNA binding, prevented encapsidation into HIV-1, HTLV-I and MLV. The Zn(2+) coordination residues of the C-terminal catalytic domain (CD2) were not required for encapsidation but were essential for cytidine deaminase activity and the antiviral effect. These findings suggest a model in which CD1 mediates encapsidation and RNA binding while CD2 mediates cytidine deaminase activity. Interestingly, HTLV-I was relatively resistant to the antiviral effects of encapsidated APOBEC3G.
- Subjects :
- APOBEC-3G Deaminase
Animals
Base Sequence
Catalytic Domain
Cytidine Deaminase
DNA genetics
Gene Deletion
Gene Products, vif physiology
Genes, Viral
Genes, vif
Genetic Complementation Test
HIV Infections enzymology
HIV Infections virology
HIV-1 genetics
Human T-lymphotropic virus 1 genetics
Human T-lymphotropic virus 1 physiology
Humans
Leukemia Virus, Murine genetics
Leukemia Virus, Murine physiology
Mice
Nucleocapsid Proteins genetics
Nucleocapsid Proteins physiology
Nucleoside Deaminases
Protein Structure, Tertiary
Repressor Proteins
Virus Assembly
Virus Replication genetics
Virus Replication physiology
Zinc chemistry
vif Gene Products, Human Immunodeficiency Virus
HIV-1 physiology
Proteins chemistry
Proteins physiology
Subjects
Details
- Language :
- English
- ISSN :
- 0042-6822
- Volume :
- 333
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Virology
- Publication Type :
- Academic Journal
- Accession number :
- 15721369
- Full Text :
- https://doi.org/10.1016/j.virol.2005.01.011