An efficient ribosomal frame-shifting signal in the polymerase-encoding region of the coronavirus IBV.
The polymerase-encoding region of the genomic RNA of the coronavirus infectious bronchitis virus (IBV) contains two very large, briefly overlapping open reading frames (ORF), F1 and F2, and it has been suggested on the basis of sequence analysis that expression of the downstream ORF, F2, might be mediated through ribosomal frame-shifting. To examine this possibility a cDNA fragment containing the F1/F2 overlap region was cloned within a marker gene and placed under the control of the bacteriophage SP6 promoter in a recombinant plasmid. Messenger RNA transcribed from this plasmid, when translated in cell-free systems, specified the synthesis of polypeptides whose size was entirely consistent with the products predicted by an efficient ribosomal frame-shifting event within the overlap region. The nature of the products was confirmed by their reactivity with antisera raised against defined portions of the flanking marker gene. This is the first non-retroviral example of ribosomal frame-shifting in higher eukaryotes.
Department of Pathology, University of Cambridge, UK.
I
I
Brierley
M E
ME
Boursnell
M M
MM
Binns
B
B
Bilimoria
V C
VC
Blok
T D
TD
Brown
S C
SC
Inglis
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003332:Coronaviridae / Q000201:enzymology / Q000235:genetics*; D012321:DNA-Directed RNA Polymerases / Q000235:genetics*; D005796:Genes; D005814:Genes, Viral; D005822:Genetic Vectors; D051379:Mice; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011401:Promoter Regions, Genetic; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics; D012367:RNA, Viral / Q000235:genetics*; D012270:Ribosomes / Q000378:metabolism*; D014158:Transcription, Genetic
D012333:RNA, Messenger; D012367:RNA, Viral; D012321:DNA-Directed RNA Polymerases