Fig. 4: vRNAP, CE and VITF-3 enable intermediate transcription and co-transcriptional capping in vitro.

A Protein composition of vRNAP complexes used for transcription assays. Complete vRNAP (lane 1), vRNAP^AraC (lane 2) and vRNAP^AraC with recombinant VITF-3 (lane 3) were separated by SDS-PAGE and visualized by silver staining. A molecular weight marker and protein names are indicated on the left and right side, respectively. Source data are provided as a Source data file. B Analysis of the promoter specificity provided by different vRNAP complexes. The vRNAP complexes shown in (A) were tested on early, intermediate (G8R) and late (A9L) promoter-containing templates in in vitro transcription assays^44,68. The composition of the assay is indicated on top, and the size of RNA products is indicated on the left, whereas early transcription yields a properly terminated product (TP) and a run-off product (RO). Source data are provided as a Source data file. C Analysis of the 5’-end of in vitro transcribed intermediate RNAs in respect to m⁷GpppN cap modifications. Transcripts of early, intermediate and T7 reactions were pooled and immunoprecipitated with the m⁷G-cap specific monoclonal antibody H-20⁵⁴. Immunoprecipitated RNAs were separated by PAGE and visualized via radioautography. Source data are provided as a Source data file. D Quantification of signal intensities from (C). Bars represent means ± SD of at least three biological replicates (dots). Source data are provided as a Source data file.