Journal of General Virology, Vol 79, 185-189, Copyright © 1998 by Society for General Microbiology
Interference with Physalis mottle tymovirus replication and coat protein synthesis by transcripts corresponding to the 3'-terminal region of the genomic RNA--role of the pseudoknot structure
CT Ranjith-Kumar, AL Haenni and HS Savithri
Department of Biochemistry, Indian Institute of Science, Bangalore.
The role of the 3' noncoding (NC) region of Physalis mottle tymovirus
genomic RNA in the multiplication of the virus was examined using an in
vivo protoplast assay system. Coat protein (CP) synthesis was specifically
inhibited by sense 3' NC region transcripts. To establish the role of the
pseudoknot structure present in the NC region in virus multiplication, four
site-specific mutants, two of which disrupted the pseudoknot structure
while the other two restored the structure, were constructed.
Interestingly, none of the four sense mutant transcripts inhibited CP
synthesis, suggesting that the specific sequence representing the 3'
terminal pseudoknot structure may play an important role in virus
multiplication. However, the wild-type antisense 3' NC transcript as well
as the four antisense mutant transcripts inhibited CP synthesis, suggesting
that the inhibitions by antisense transcripts could be due to the formation
of RNA-RNA hybrids at the 3' end of the genomic RNA.
