Previous Article | Next Article ![]()
J. Virol., 08 1997, 6233-6236, Vol 71, No. 8
AV Karasev, ME Hilf, SM Garnsey and WO Dawson
Citrus tristeza virus (CTV) induces formation of a nested set of at least
nine 3' coterminal subgenomic RNAs (sgRNAs) in infected tissue. The
organization and expression of the 19,296-nucleotide (nt) CTV genome
resembles that of coronaviruses, with polyprotein processing, translational
frameshifting, and multiple sgRNA formation, but phylogenetically the CTV
polymerase, like polymerases of other closteroviruses, belongs to the
Sindbis virus-like lineage of RNA virus polymerases. Both positive-strand
RNA virus supergroups, coronaviruses and Sindbis-like viruses, utilize
different mechanisms of transcription. To address the mechanism of CTV
transcription, 5' termini for the two most abundant sgRNAs, 1.5 and 0.9 kb,
respectively, were mapped by runoff reverse transcription. The two sgRNAs
were demonstrated to have 48- and 38-nt 5' untranslated regions (5'-UTRs),
respectively. The 5'-UTR for the 1.5-kb RNA was cloned, sequenced, and
demonstrated to be colinear with the 48-nt genomic sequence upstream of the
initiator codon of the respective open reading frame 10, i.e., to be of
continuous template origin. The data obtained suggest that the sgRNA
transcription of CTV is dissimilar from the coronavirus transcription and
consistent with the transcriptional mechanism of other Sindbis-like
viruses. Thus, the Sindbis virus-like mechanism of transcription of the
positive-strand RNA genomes might be successfully utilized by the
closterovirus genome of up to 19.3 kb with multiple sgRNAs.
Copyright © 1997, American Society for Microbiology
Transcriptional strategy of closteroviruses: mapping the 5' termini of the citrus tristeza virus subgenomic RNAs
Citrus Research and Education Center, University of Florida, Lake Alfred 33850-2299, USA.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»