Sequence analysis of the 3'-end of the feline coronavirus FIPV 79-1146 genome: comparison with the genome of porcine coronavirus TGEV reveals large insertions.
The genetic information, carried on mRNA 6 of feline infectious peritonitis virus (FIPV) strain 79-1146, was determined by sequence analysis of cDNA clones derived from the 3' end of the FIPV genome. Two ORFs were found, encoding polypeptides of 11K (ORF-1) and 22K (ORF-2). The FIPV sequence was compared to the 3' end sequence of transmissible gastroenteritis virus (TGEV). ORF-1 has a homologous counterpart (ORF-X3) in the TGEV genome; both ORFs are located at the same position relative to the nucleocapsid gene. However, as a result of an in-frame insertion or deletion, ORF-1 is 69 nucleotides larger than ORF-X3. A similar event has occurred immediately downstream of ORF1: a 624-nucleotide segment, containing the complete ORF-2, is absent in the TGEV sequence. Most sequence similarity (98.5%) was found in the 3' noncoding sequences. ORF-X3 and ORF-1 are preceded by the sequence AACTAAAC, which is assumed to be the transcription-initiation signal in FIPV and TGEV (P.A. Kapke and D.A. Brian (1986) Virology 151, 41-49). By S1 nuclease analysis, the 5' end of FIPV RNA 6 was mapped immediately upstream of this sequence. A 700-nucleotide TGEV-specific RNA was found by cross-hybridization with an FIPV 3' end probe, suggesting that TGEV ORF-X3 is also carried on a separate mRNA. The differences at the 3' ends of the FIPV and TGEV genomes may be the result of RNA recombination events.
De Groot
R J
RJ
Institute of Virology, Veterinary Faculty, State University of Utrecht, The Netherlands.
Andeweg
A C
AC
Horzinek
M C
MC
Spaan
W J
WJ
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002415:Cats / Q000382:microbiology; D003332:Coronaviridae / Q000235:genetics*; D004247:DNA / Q000235:genetics; D005796:Genes; D012333:RNA, Messenger / Q000235:genetics; D012367:RNA, Viral / Q000235:genetics*; D011995:Recombination, Genetic; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid; D013552:Swine / Q000382:microbiology
D012333:RNA, Messenger; D012367:RNA, Viral; D004247:DNA