Two mRNAs are transcribed from banana bunchy top virus DNA-1

• Published in: Journal of general virology Vol. 78; no. 1; pp. 229 - 236
• Main Authors: Beetham, PR, Hafner, GJ, Harding, RM, Dale, JL
• Format: Journal Article
• Language: English
• Published: England Soc General Microbiol 01-01-1997
• Subjects: Agrobacterium tumefaciens; Amino Acid Sequence; Animals; Aphids; banana bunchy top virus; Base Sequence; Circovirus - genetics; Circovirus - metabolism; DNA Primers; DNA, Viral - metabolism; Fruit - virology; Molecular Sequence Data; Nicotiana; Open Reading Frames; Plants, Genetically Modified; Plants, Toxic; RNA Probes; RNA, Messenger - biosynthesis; RNA, Viral - biosynthesis; Transcription, Genetic
• ISSN: 0022-1317; 1465-2099
• DOI: 10.1099/0022-1317-78-1-229

PR Beetham, GJ Hafner, RM Harding and JL Dale
Centre for Molecular Biotechnology, School of Life Science, Queensland University of Technology, Brisbane, Australia.
We have mapped the mRNA transcripts of banana bunchy top virus (BBTV)
DNA-1. Northern hybridization and 3' RACE analysis identified two poly-
adenylated RNAs associated with BBTV DNA-1. Previously, one major ORF in
the virion sense of DNA-1 had been identified, which encoded a putative
replication protein (Rep). An mRNA was identified in BBTV infected bananas
that was clearly transcribed from this Rep ORF. Further, a second
transcript was identified which mapped to an ORF completely within the Rep
ORF. This encoded a putative 5 kDa protein of unknown function. Both these
transcripts were also identified in a tobacco plant that had been
transformed with Agrobacterium tumefaciens harbouring a binary construct
containing the Rep ORF from BBTV DNA-1. This Rep ORF was inserted 3' of a
cauliflower mosaic virus 35S promoter and 5' of a vegetable storage protein
terminator. The transcripts mapped from these tobacco plants were identical
at the 3' end to the transcripts from BBTV infected banana plants. The site
of polyadenylation for the Rep ORF was at base 963 immediately 3' of the
translational stop codon confirming that the polyadenylation signals for
this transcript were all within the ORF. However, the internal ORF had a
large untranslated region of 272 bases with its site of polyadenylation at
nucleotide 803 and a polyadenylation signal 3' of the translational stop
codon. A possible upstream termination signal (A/TTGTAA) was identified and
was conserved within BBTV DNA-1 sequences from different international
isolates.