Anticodon-like binding of the HIV-1 tRNA-like element to human lysyl-tRNA synthetase
- 1Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, USA
- 2Department of Chemistry and Biochemistry, Center for Retrovirus Research and Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA
- Corresponding authors: musier{at}chemistry.ohio-state.edu, pearl.tsang{at}uc.edu
Abstract
A critical step in the HIV-1 lifecycle involves reverse transcription of the viral genomic RNA (gRNA). Human tRNALys3 serves as a primer for transcription initiation and is selectively enriched in virus particles. Human lysyl-tRNA synthetase (hLysRS) is also packaged into virions. Recently, a tRNA-like element (TLE) within the HIV-1 gRNA was shown to mimic the global tRNA fold and bind competitively to hLysRS, suggesting a mechanism of tRNA targeting to the primer binding site (PBS) and release from the synthetase. Here, we use NMR to investigate hLysRS anticodon-binding domain (ACB) binding to six RNA oligonucleotides, including a hairpin derived from the HIV-1 gRNA TLE. We show that ACB interacts with submicromolar affinity to U-rich RNA oligonucleotides—the tRNALys3 anticodon stem–loop (ACSL), the WT TLE, and a nonanucleotide, U9. In contrast, the ACB bound only weakly to two TLE loop mutants and a C9 nonanucleotide. NMR chemical shift perturbations induced by each RNA indicate that the ACSL and the WT TLE both interact with the ACB in a strikingly similar manner. Taken together, these findings support the conclusion that tRNA mimicry by the HIV-1 genome leads to a highly specific protein–RNA interaction that facilitates efficient primer release from hLysRS prior to reverse transcription.
Keywords
- anticodon-binding domain
- human lysyl-tRNA synthetase
- tRNA-like element
- HIV-1 genome
- NMR
- chemical shift perturbation
Footnotes
-
Article published online ahead of print. Article and publication date are at http://www.rnajournal.org/cgi/doi/10.1261/rna.058081.116.
- Received June 27, 2016.
- Accepted September 10, 2016.
This article is distributed exclusively by the RNA Society for the first 12 months after the full-issue publication date (see http://rnajournal.cshlp.org/site/misc/terms.xhtml). After 12 months, it is available under a Creative Commons License (Attribution-NonCommercial 4.0 International), as described at http://creativecommons.org/licenses/by-nc/4.0/.