Biomaterial Database

Deaminase-independent inhibition of HIV-1 reverse transcription by APOBEC3G. 2007

Yasumasa Iwatani, and Denise S B Chan, and F Wang, and Kristen Stewart-Maynard, and Wataru Sugiura, and Angela M Gronenborn, and Ioulia Rouzina, and Mark C Williams, and Karin Musier-Forsyth, and Judith G Levin

Laboratory of Molecular Genetics, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.

APOBEC3G (A3G), a host protein that inhibits HIV-1 reverse transcription and replication in the absence of Vif, displays cytidine deaminase and single-stranded (ss) nucleic acid binding activities. HIV-1 nucleocapsid protein (NC) also binds nucleic acids and has a unique property, nucleic acid chaperone activity, which is crucial for efficient reverse transcription. Here we report the interplay between A3G, NC and reverse transcriptase (RT) and the effect of highly purified A3G on individual reactions that occur during reverse transcription. We find that A3G did not affect the kinetics of NC-mediated annealing reactions, nor did it inhibit RNase H cleavage. In sharp contrast, A3G significantly inhibited all RT-catalyzed DNA elongation reactions with or without NC. In the case of (-) strong-stop DNA synthesis, the inhibition was independent of A3G's catalytic activity. Fluorescence anisotropy and single molecule DNA stretching analyses indicated that NC has a higher nucleic acid binding affinity than A3G, but more importantly, displays faster association/disassociation kinetics. RT binds to ssDNA with a much lower affinity than either NC or A3G. These data support a novel mechanism for deaminase-independent inhibition of reverse transcription that is determined by critical differences in the nucleic acid binding properties of A3G, NC and RT.

UI	MeSH Term	Description	Entries
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D003564	Cytidine Deaminase	An enzyme that catalyzes the deamination of cytidine, forming uridine. EC 3.5.4.5.	Cytidine Aminohydrolase,Aminohydrolase, Cytidine,Deaminase, Cytidine
D004277	DNA, Single-Stranded	A single chain of deoxyribonucleotides that occurs in some bacteria and viruses. It usually exists as a covalently closed circle.	Single-Stranded DNA,DNA, Single Stranded,Single Stranded DNA
D004279	DNA, Viral	Deoxyribonucleic acid that makes up the genetic material of viruses.	Viral DNA
D005454	Fluorescence Polarization	Measurement of the polarization of fluorescent light from solutions or microscopic specimens. It is used to provide information concerning molecular size, shape, and conformation, molecular anisotropy, electronic energy transfer, molecular interaction, including dye and coenzyme binding, and the antigen-antibody reaction.	Anisotropy, Fluorescence,Fluorescence Anisotropy,Polarization, Fluorescence,Anisotropies, Fluorescence,Fluorescence Anisotropies,Fluorescence Polarizations,Polarizations, Fluorescence
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000071480	APOBEC-3G Deaminase	An APOBEC deaminase that functions as an inhibitor of RETROVIRIDAE replication and inhibits the mobility of RETROTRANSPOSONS via deaminase-dependent and independent mechanisms. It is selective for SINGLE-STRANDED DNA and does not deaminate double-stranded DNA or single or DOUBLE-STRANDED RNA. It exhibits potent antiviral activity against VIF PROTEIN deficient HIV-1 through the creation of hypermutations in the VIRAL DNA. It also has anti-viral activity against SIMIAN IMMUNODEFICIENCY VIRUSES and HEPATITIS B VIRUS.	APOBEC-3G Protein,APOBEC-3G dC-dU Editing Enzyme,APOBEC-Related Cytidine Deaminase,APOBEC-Related Protein,APOBEC3G Deaminase,APOBEC3G Protein,CEM15 Protein,APOBEC 3G Deaminase,APOBEC 3G Protein,APOBEC 3G dC dU Editing Enzyme,APOBEC Related Cytidine Deaminase,APOBEC Related Protein,Cytidine Deaminase, APOBEC-Related,Deaminase, APOBEC-3G,Deaminase, APOBEC3G
D001483	Base Sequence	The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.	DNA Sequence,Nucleotide Sequence,RNA Sequence,DNA Sequences,Base Sequences,Nucleotide Sequences,RNA Sequences,Sequence, Base,Sequence, DNA,Sequence, Nucleotide,Sequence, RNA,Sequences, Base,Sequences, DNA,Sequences, Nucleotide,Sequences, RNA
D012313	RNA	A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)	RNA, Non-Polyadenylated,Ribonucleic Acid,Gene Products, RNA,Non-Polyadenylated RNA,Acid, Ribonucleic,Non Polyadenylated RNA,RNA Gene Products,RNA, Non Polyadenylated
D015497	HIV-1	The type species of LENTIVIRUS and the etiologic agent of AIDS. It is characterized by its cytopathic effect and affinity for the T4-lymphocyte.	Human immunodeficiency virus 1,HIV-I,Human Immunodeficiency Virus Type 1,Immunodeficiency Virus Type 1, Human