title: Priming of reovirus transcription by GppppG and formation of CpG(5')GpC.
abstract: Compounds of general structure N(5')pn(5')N were used by the reovirus-associated RNA polymerase as primers for template-directed synthesis of virus-specific oligonucleotides and RNA. Structural requirements for activity included a guanosine residue and at least four phosphates--i.e., G(5')pppp(5')N. Gp4G incubated with viral cores in the presence of CTP yielded Gp4GpC and CpGp4GpC. In a complete transcription mixture, Gp4G was also incorporated into the 5' termini of full-length transcripts in the unmethylated forms Gp4GpC and CpGp4GpC, in contrast to viral mRNAs that contain 5'-terminal m7GpppGmpC formed de novo. Gp5G, Gp6G, and Gp4A but not Gp2G, Gp3G, and Ap4A also primed reovirus transcription and inhibited RNA methylation.
mesh_terms: D015226:Dinucleoside Phosphates; D006150:Guanine Nucleotides / Q000494:pharmacology*; D006159:Guanosine Tetraphosphate / Q000031:analogs & derivatives / Q000494:pharmacology*; D012089:Mammalian orthoreovirus 3 / Q000235:genetics*; D009843:Oligoribonucleotides / Q000096:biosynthesis; D012315:RNA Caps / Q000096:biosynthesis; D012333:RNA, Messenger / Q000096:biosynthesis*; D012367:RNA, Viral / Q000096:biosynthesis; D012087:Reoviridae / Q000235:genetics*; D014158:Transcription, Genetic / Q000187:drug effects*
chemical_list: D015226:Dinucleoside Phosphates; D006150:Guanine Nucleotides; D009843:Oligoribonucleotides; D012315:RNA Caps; D012333:RNA, Messenger; D012367:RNA, Viral; D006159:Guanosine Tetraphosphate; C015138:diguanosine tetraphosphate