title: Allosteric effects of ligands and mutations on poliovirus RNA-dependent RNA polymerase.
abstract: Protein priming of viral RNA synthesis plays an essential role in the replication of picornavirus RNA. Both poliovirus and coxsackievirus encode a small polypeptide, VPg, which serves as a primer for addition of the first nucleotide during synthesis of both positive and negative strands. This study examined the effects on the VPg uridylylation reaction of the RNA template sequence, the origin of VPg (coxsackievirus or poliovirus), the origin of 3D polymerase (coxsackievirus or poliovirus), the presence and origin of interacting protein 3CD, and the introduction of mutations at specific regions in the poliovirus 3D polymerase. Substantial effects associated with VPg origin were traced to differences in VPg-polymerase interactions. The effects of 3CD proteins and mutations at polymerase-polymerase intermolecular Interface I were most consistent with allosteric effects on the catalytic 3D polymerase molecule. In conclusion, the efficiency and specificity of VPg uridylylation by picornavirus polymerases is greatly influenced by allosteric effects of ligand binding that are likely to be relevant during the viral replicative cycle.
authors.affiliation: Stanford University School of Medicine, Department of Microbiology and Immunology, Fairchild Science Building D309A, Stanford, CA 94305-5402, USA.
authors.forename: Joanna E
authors.initials: JE
authors.lastname: Boerner
authors.forename: John M
authors.initials: JM
authors.lastname: Lyle
authors.forename: Sarah
authors.initials: S
authors.lastname: Daijogo
authors.forename: Bert L
authors.initials: BL
authors.lastname: Semler
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Schultz
authors.forename: Karla
authors.initials: K
authors.lastname: Kirkegaard
authors.forename: Oliver C
authors.initials: OC
authors.lastname: Richards
mesh_terms: D000494:Allosteric Regulation; D000495:Allosteric Site; D001665:Binding Sites; D015967:Gene Expression Regulation, Viral; D006801:Humans; D008024:Ligands; D008958:Models, Molecular; D009154:Mutation; D017955:Poliovirus / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012324:RNA-Dependent RNA Polymerase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D013698:Templates, Genetic; D014542:Uridine Monophosphate / Q000378:metabolism*; D014758:Viral Core Proteins / Q000378:metabolism
chemical_list: D008024:Ligands; D012367:RNA, Viral; D014758:Viral Core Proteins; D014542:Uridine Monophosphate; C090443:polymerase 3Dpol, poliovirus; D012324:RNA-Dependent RNA Polymerase