title: Structure of the Vif-binding domain of the antiviral enzyme APOBEC3G.
abstract: The human APOBEC3G (A3G) DNA cytosine deaminase restricts and hypermutates DNA-based parasites including HIV-1. The viral infectivity factor (Vif) prevents restriction by triggering A3G degradation. Although the structure of the A3G catalytic domain is known, the structure of the N-terminal Vif-binding domain has proven more elusive. Here, we used evolution- and structure-guided mutagenesis to solubilize the Vif-binding domain of A3G, thus permitting structural determination by NMR spectroscopy. A smaller zinc-coordinating pocket and altered helical packing distinguish the structure from previous catalytic-domain structures and help to explain the reported inactivity of this domain. This soluble A3G N-terminal domain is bound by Vif; this enabled mutagenesis and biochemical experiments, which identified a unique Vif-interacting surface formed by the α1-β1, β2-α2 and β4-α4 loops. This structure sheds new light on the Vif-A3G interaction and provides critical information for future drug development.
authors.affiliation: 1] Biochemistry, Molecular Biology and Biophysics Department, Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota, USA. [2] Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
authors.forename: Takahide
authors.initials: T
authors.lastname: Kouno
authors.affiliation: Biochemistry, Molecular Biology and Biophysics Department, Masonic Cancer Center, Center for Genome Engineering, Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Luengas
authors.affiliation: Biochemistry, Molecular Biology and Biophysics Department, Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Megumi
authors.initials: M
authors.lastname: Shigematsu
authors.affiliation: Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
authors.forename: Shivender M D
authors.initials: SM
authors.lastname: Shandilya
authors.affiliation: Biochemistry, Molecular Biology and Biophysics Department, Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: JingYing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Biochemistry, Molecular Biology and Biophysics Department, Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Luan
authors.initials: L
authors.lastname: Chen
authors.affiliation: Biochemistry, Molecular Biology and Biophysics Department, Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Mayuko
authors.initials: M
authors.lastname: Hara
authors.affiliation: Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
authors.forename: Celia A
authors.initials: CA
authors.lastname: Schiffer
authors.affiliation: Biochemistry, Molecular Biology and Biophysics Department, Masonic Cancer Center, Center for Genome Engineering, Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Reuben S
authors.initials: RS
authors.lastname: Harris
authors.affiliation: Biochemistry, Molecular Biology and Biophysics Department, Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Matsuo
mesh_terms: D000071480:APOBEC-3G Deaminase; D003564:Cytidine Deaminase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D004252:DNA Mutational Analysis; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D050505:Mutant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D025941:Protein Interaction Mapping; D054320:vif Gene Products, Human Immunodeficiency Virus / Q000378:metabolism*
chemical_list: D050505:Mutant Proteins; D054320:vif Gene Products, Human Immunodeficiency Virus; C514847:vif protein, Human immunodeficiency virus 1; D000071480:APOBEC-3G Deaminase; C464924:APOBEC3G protein, human; D003564:Cytidine Deaminase