Structure-Function Model for Kissing Loop Interactions That Initiate Dimerization of Ty1 RNA
AbstractThe genomic RNA of the retrotransposon Ty1 is packaged as a dimer into virus-like particles. The 5′ terminus of Ty1 RNA harbors cis-acting sequences required for translation initiation, packaging and initiation of reverse transcription (TIPIRT). To identify RNA motifs involved in dimerization and packaging, a structural model of the TIPIRT domain in vitro was developed from single-nucleotide resolution RNA structural data. In general agreement with previous models, the first 326 nucleotides of Ty1 RNA form a pseudoknot with a 7-bp stem (S1), a 1-nucleotide interhelical loop and an 8-bp stem (S2) that delineate two long, structured loops. Nucleotide substitutions that disrupt either pseudoknot stem greatly reduced helper-Ty1-mediated retrotransposition of a mini-Ty1, but only mutations in S2 destabilized mini-Ty1 RNA in cis and helper-Ty1 RNA in trans. Nested in different loops of the pseudoknot are two hairpins with complementary 7-nucleotide motifs at their apices. Nucleotide substitutions in either motif also reduced retrotransposition and destabilized mini- and helper-Ty1 RNA. Compensatory mutations that restore base-pairing in the S2 stem or between the hairpins rescued retrotransposition and RNA stability in cis and trans. These data inform a model whereby a Ty1 RNA kissing complex with two intermolecular kissing-loop interactions initiates dimerization and packaging. View Full-Text
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Gamache, E.R.; Doh, J.H.; Ritz, J.; Laederach, A.; Bellaousov, S.; Mathews, D.H.; Curcio, M.J. Structure-Function Model for Kissing Loop Interactions That Initiate Dimerization of Ty1 RNA. Viruses 2017, 9, 93.
Gamache ER, Doh JH, Ritz J, Laederach A, Bellaousov S, Mathews DH, Curcio MJ. Structure-Function Model for Kissing Loop Interactions That Initiate Dimerization of Ty1 RNA. Viruses. 2017; 9(5):93.Chicago/Turabian Style
Gamache, Eric R.; Doh, Jung H.; Ritz, Justin; Laederach, Alain; Bellaousov, Stanislav; Mathews, David H.; Curcio, M. J. 2017. "Structure-Function Model for Kissing Loop Interactions That Initiate Dimerization of Ty1 RNA." Viruses 9, no. 5: 93.
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