Related Experiment Video
Updated: Aug 17, 2026

Isolation of Fidelity Variants of RNA Viruses and Characterization of Virus Mutation Frequency
Published on: June 16, 2011
Full-length tobacco mosaic virus RNAs and defective RNAs have different 3' replication signals
R Chandrika1, S Rabindran, D J Lewandowski
1Department of Plant Pathology, University of Florida, CREC, Lake Alfred, Florida, 33850, USA.
Abstract:
The viral replicase complex of positive-stranded RNA viruses interacts with cis-acting elements that are usually located at the termini of the viral RNAs. On comparison of the replication requirement of a tobacco mosaic virus (TMV)-based defective RNA (dRNA) and its helper virus, we found different requirements for replication of TMV RNAs in cis and in trans. The level of replication of full-length TMV RNA decreased substantially in the absence of pseudoknot (pk) 1 and/or 2, whereas identical deletions in dRNAs did not affect their replication. However, pk3 was required for replication of both full-length TMV RNAs and dRNAs. The requirements for homologous sequences were greater for dRNA replication than for replication of full-length TMV RNAs. Defective RNAs with heterologous 3' nontranslated regions (NTRs) failed to be replicated or replicated minimally, whereas replication of similarly mutated full-length RNAs was much less affected. Increasing amounts of contiguous heterologous sequences in the dRNAs compensated for the impaired interactions between the replicase and 3' NTR. The precision requirement appeared to involve the terminal 28 nucleotides, specifically the pseudoknot in the aminoacyl acceptor arm of the tRNA like structure, which was important in replication of both dRNAs and full-length TMV RNAs.
Related Concept Videos
Retrovirus Life Cycles
Viral Mutations
Leaky Scanning
Size and Structure of Viral Genomes
Viruses with RNA Genomes
Subviral Agents

