Mutations in the RNA-binding domains of tombusvirus replicase proteins affect RNA recombination in vivo

Živile Panaviene, Peter D. Nagy

Research output: Contribution to journalArticlepeer-review

41 Scopus citations


RNA recombination, which is thought to occur due to replicase errors during viral replication, is one of the major driving forces of virus evolution. In this article, we show evidence that the replicase proteins of Cucumber necrosis virus, a tombusvirus, are directly involved in RNA recombination in vivo. Mutations within the RNA-binding domains of the replicase proteins affected the frequency of recombination observed with a prototypical defective-interfering (DI) RNA, a model template for recombination studies. Five of the 17 replicase mutants tested showed delay in the formation of recombinants when compared to the wild-type helper virus. Interestingly, two replicase mutants accelerated recombinant formation and, in addition, these mutants also increased the level of subgenomic RNA synthesis (Virology 308 (2003), 191-205). A trans-complementation system was used to demonstrate that mutation in the p33 replicase protein resulted in altered recombination rate. Isolated recombinants were mostly imprecise (nonhomologous), with the recombination sites clustered around a replication enhancer region and a putative cis-acting element, respectively. These RNA elements might facilitate the proposed template switching events by the tombusvirus replicase. Together with data in the article cited above, results presented here firmly establish that the conserved RNA-binding motif of the replicase proteins is involved in RNA replication, subgenomic RNA synthesis, and RNA recombination.

Original languageEnglish
Pages (from-to)359-372
Number of pages14
Issue number2
StatePublished - Dec 20 2003

Bibliographical note

Funding Information:
We thank Dr. Judit Pogany and K.S. Rajendran for their critical comments. We are also grateful to Ms. Jannine Baker for her technical assistance. This work was supported by NSF (MCB0078152) and by the Kentucky Tobacco Research and Development Center at the University of Kentucky. This study is Publication No. 03-12-092 of the Kentucky Agricultural Experiment Station.


  • Cucumber necrosis virus
  • Defective-interfering RNA
  • RNA binding
  • RNA replication enhancer
  • Recombination
  • Replicase
  • Replication
  • Subgenomic RNA
  • Template switching
  • Tomato bushy stunt virus

ASJC Scopus subject areas

  • Virology


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