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Structure of Vaccinia Virus DNA-dependent RNA polymerase co-transcriptional capping complexStructure of Vaccinia Virus DNA-dependent RNA polymerase co-transcriptional capping complex
Structural highlights
FunctionRP30_VACCA Part of the DNA-dependent RNA polymerase which catalyzes the transcription of viral DNA into RNA using the four ribonucleoside triphosphates as substrates. Responsible for the transcription of early, intermediate and late genes. DNA-dependent RNA polymerase associates with the early transcription factor (ETF), itself composed of OPG118/D6 and OPG134/A8, thereby allowing the early genes transcription. Late transcription, and probably also intermediate transcription, require newly synthesized RNA polymerase.[1] Publication Abstract from PubMedPoxviruses use virus-encoded multisubunit RNA polymerases (vRNAPs) and RNA-processing factors to generate m(7)G-capped mRNAs in the host cytoplasm. In the accompanying paper, we report structures of core and complete vRNAP complexes of the prototypic Vaccinia poxvirus (Grimm et al., 2019; in this issue of Cell). Here, we present the cryo-electron microscopy (cryo-EM) structures of Vaccinia vRNAP in the form of a transcribing elongation complex and in the form of a co-transcriptional capping complex that contains the viral capping enzyme (CE). The trifunctional CE forms two mobile modules that bind the polymerase surface around the RNA exit tunnel. RNA extends from the vRNAP active site through this tunnel and into the active site of the CE triphosphatase. Structural comparisons suggest that growing RNA triggers large-scale rearrangements on the surface of the transcription machinery during the transition from transcription initiation to RNA capping and elongation. Our structures unravel the basis for synthesis and co-transcriptional modification of poxvirus RNA. Structural Basis of Poxvirus Transcription: Transcribing and Capping Vaccinia Complexes.,Hillen HS, Bartuli J, Grimm C, Dienemann C, Bedenk K, Szalay AA, Fischer U, Cramer P Cell. 2019 Dec 12;179(7):1525-1536.e12. doi: 10.1016/j.cell.2019.11.023. PMID:31835031[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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