Evidence that virion-associated VP1 of avibirnaviruses contains viral RNA sequences.
The VP1 encoded by genomic segment B of birnaviruses is generally known to exist as a genome-linked protein (VPg) and as a "free" polypeptide of 90 kDa in virus particles. The guanylylation activity associated with infectious bursal disease virus (IBDV) was demonstrated by incubating purified virus in presence of [alpha 32P] GTP; optimum activity in the 90 kDa form of VP1 was seen in low salt concentration in the presence of 4 mM magnesium ions over a wide range of incubation temperatures. The IBDV VP1 was shown to lack guanyl transferase activity. Northwestern (RNA-protein) blot analysis of purified virus using a radiolabelled cDNA probe consisting of 3' and 5' ends of genomic segment B indicated that both forms of virion-associated VP1 contained viral RNA sequences of which those linked to VPg corresponded to the two genome segments and those linked to the 90 kDa VP1 were probably a short oligonucleotide of the terminal viral RNA sequences.
Kibenge
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FS
Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Canada.
Dhama
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D000818:Animals; D002213:Capsid / Q000378:metabolism*; D036022:Capsid Proteins; D002522:Chlorocebus aethiops; D006160:Guanosine Triphosphate / Q000378:metabolism / Q000494:pharmacology; D007243:Infectious bursal disease virus / Q000378:metabolism*; D009713:Nucleotidyltransferases / Q000378:metabolism; D012367:RNA, Viral / Q000378:metabolism*; D014709:Vero Cells; D014758:Viral Core Proteins / Q000378:metabolism*; D014771:Virion
D036022:Capsid Proteins; D012367:RNA, Viral; D014758:Viral Core Proteins; D006160:Guanosine Triphosphate; D009713:Nucleotidyltransferases; C020842:guanylyltransferase