title: Sequence comparison of the 5' end of mRNA 3 from transmissible gastroenteritis virus and porcine respiratory coronavirus.
abstract: Analysis of porcine transmissible gastroenteritis virus (TGEV) and porcine respiratory coronavirus (PRCV) mRNA species indicated a deletion in mRNA 3 of PRCV. Polymerase chain reaction (PCR) was used to clone the 5' end of mRNA 3 from PRCV for comparison with the equivalent region in TGEV. Small deletions were observed within and around the PRCV sequence equivalent to the putative open reading frame (ORF) ORF-3a identified in TGEV. The potential RNA polymerase-leader complex binding site (leader RNA binding site), ACTAAAC, found upstream of ORF-3a in TGEV, was absent from the PRCV genome but a potential site was found in the PRCV genome upstream of a gene equivalent to TGEV ORF-3b. PCR analysis, using primers corresponding to sequences within the ORF-3b gene and the leader RNA sequence, confirmed that the leader RNA binding site was upstream of a gene equivalent to TGEV ORF-3b on PRCV mRNA 3 but upstream of ORF-3a on TGEV mRNA 3. The presence of the new leader RNA binding site would be responsible for generating the smaller mRNA 3 species found in PRCV-infected cells.
authors.affiliation: AFRC Institute for Animal Health, Compton Laboratory, Newbury, Berkshire, U.K.
authors.forename: K W
authors.initials: KW
authors.lastname: Page
authors.forename: K L
authors.initials: KL
authors.lastname: Mawditt
authors.forename: P
authors.initials: P
authors.lastname: Britton
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001345:Autoradiography; D001483:Base Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D003332:Coronaviridae / Q000235:genetics*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics*; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics*; D005760:Transmissible gastroenteritis virus / Q000235:genetics*
chemical_list: D012333:RNA, Messenger; D012367:RNA, Viral