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Structure-function analyses point to a polynucleotide-accommodating groove essential for APOBEC3A restriction activities.

Type of publication Peer-reviewed
Publikationsform Original article (peer-reviewed)
Publication date 2011
Author Bulliard Yannick, Narvaiza Iñigo, Bertero Alessandro, Peddi Shyam, Röhrig Ute F, Ortiz Millán, Zoete Vincent, Castro-Díaz Nataly, Turelli Priscilla, Telenti Amalio, Michielin Olivier, Weitzman Matthew D, Trono Didier,
Project Host evolutionary genomics of HIV-1 and other retroviruses
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Original article (peer-reviewed)

Journal Journal of virology
Volume (Issue) 85(4)
Page(s) 1765 - 76
Title of proceedings Journal of virology
DOI 10.1128/JVI.01651-10


Members of the human APOBEC3 family of editing enzymes can inhibit various mobile genetic elements. APOBEC3A (A3A) can block the retrotransposon LINE-1 and the parvovirus adeno-associated virus type 2 (AAV-2) but does not inhibit retroviruses. In contrast, APOBEC3G (A3G) can block retroviruses but has only limited effects on AAV-2 or LINE-1. What dictates this differential target specificity remains largely undefined. Here, we modeled the structure of A3A based on its homology with the C-terminal domain of A3G and further compared the sequence of human A3A to those of 11 nonhuman primate orthologues. We then used these data to perform a mutational analysis of A3A, examining its ability to restrict LINE-1, AAV-2, and foreign plasmid DNA and to edit a single-stranded DNA substrate. The results revealed an essential functional role for the predicted single-stranded DNA-docking groove located around the A3A catalytic site. Within this region, amino acid differences between A3A and A3G are predicted to affect the shape of the polynucleotide-binding groove. Correspondingly, transferring some of these A3A residues to A3G endows the latter protein with the ability to block LINE-1 and AAV-2. These results suggest that the target specificity of APOBEC3 family members is partly defined by structural features influencing their interaction with polynucleotide substrates.