Fig. 1: M1249L plays a crucial role in the activity of ASFV vRNAP.

a Schematic representation of modified ASFV genes. A DNA fragment encoding a Twin strep tag was fused in HLJ/18-6GD to the 3’ end of EP1242L, allowing the expression of C-terminally tagged vRPB2. b Proteins eluted from XT beads visualized by silver staining on a 12.5% SDS-PAGE. RNA polymerase eight subunits are colored blue, transcription factors are colored red, and pollutant proteins are colored gray. Protein bands were characterized by the molecular weight marker and identified by MS Fingerprinting analysis, with protein names indicated on the left next to their corresponding bands. The experiment was repeated independently twice with similar results. c UMAP analysis of the ASFV transcriptome demonstrates expression patterns of vRNAP and transcription factors across various stages. Purple dots denote immediate early-expressed genes, brown dots denote early-expressed genes, blue dots denote mid-term expressed genes and pink dots denote late-expressed genes. d The transcriptome analysis of ASFV vRNAP subunits plus M1249L (top) and transcription factors (bottom) at different time points post-infection (n = 3). Data are presented as mean values +/- SD. e Measurement of vRNAP complex molecular weight at different time points by mass spectrometry. The peak of core RNAP is colored cyan, while the vRNAP-M1249L complex is colored orange. f The proportion of vRNAP-M1249L complexes determined by mass spectrometry (top) as well as silver staining (bottom) relative to the total particles in the sample g. h HEK293T cells were transfected with plasmids of p72-Fluc and varying doses of M1249L, the luminescence was detected by luminometer (n = 3). Data are presented as mean values +/- SD. i HEK293T cells were transfected with p72-Fluc with or without certain transcription factor, the luminescence was detected by luminometer (n = 3). Data are presented as mean values +/- SD. Statistical analysis was performed by unpaired t test. P values are marked. Source data are provided as a Source Data file.