Self-catalyzed linkage of poliovirus terminal protein VPg to poliovirus RNA.
The poliovirus terminal protein, VPg, was covalently linked to poliovirus RNA in a reaction that required synthetic VPg, Mg2+, and a replication intermediate synthesized in vitro. The VPg linkage reaction did not require the viral polymerase, host factor, or ribonucleoside triphosphates and was specific for template-linked minus-strand RNA synthesized on poliovirion RNA. The covalent nature of the bond between VPg and the RNA was demonstrated by the isolation of VPg-pUp from VPg-linked RNA. A model is proposed in which the tyrosine residue in VPg forms a phosphodiester bond with the 5'UMP in minus-strand RNA in a self-catalyzed transesterification reaction. It appears that either the RNA, VPg, or a combination of both forms the catalytic center for this reaction.
Tobin
G J
GJ
Department of Immunology and Medical Microbiology College of Medicine, University of Florida, Gainesville 32610.
Young
D C
DC
Flanegan
J B
JB
D001483:Base Sequence; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D008040:Genetic Linkage; D007700:Kinetics; D015636:Magnesium Chloride / Q000494:pharmacology; D008969:Molecular Sequence Data; D017955:Poliovirus / Q000235:genetics* / Q000378:metabolism; D011485:Protein Binding; D012367:RNA, Viral / Q000302:isolation & purification / Q000378:metabolism*; D013816:Thermodynamics; D014758:Viral Core Proteins / Q000378:metabolism*
D012367:RNA, Viral; D014758:Viral Core Proteins; D015636:Magnesium Chloride; D012321:DNA-Directed RNA Polymerases