Fig. 4: Structure of the ASFV RNAP elongation complex (EC).

a The overall structure of the ASFV EC is depicted in cartoon representation. The subunit colors are identical to those in Fig. 2. Helices are represented as cylinders. Nucleic acids are shown in blue (template strand DNA), sky blue (non-template strand DNA) and purple (RNA). The active site magnesium and zinc ions are shown as red and cyan spheres, respectively. b A close-up view of the active center of the ASFV EC. The protein and nucleic acid are represented as sticks. The cryo-EM density is shown as a gray mesh. c Comparison of the active center in ASFV EC with that of the VACV EC (PDB: 6RID¹⁶). Residues interacting with nucleic acids are generated by PDBsum⁴⁶ and are indicated. Residues interacting with nucleic acids are shown as sticks in ASFV EC (green) and VACV EC (gray). Residues specific to ASFV EC are highlighted in red. d A schematic representation of the nucleic acid scaffold used in this study. Individual bases are shown as squares, and the bases are abbreviated using one-letter codes. The bases visible in the EC structure are represented as solid squares, while the invisible bases are shown as hollow squares. The active-site Mg²⁺ is depicted as a red circle. Residues specific to ASFV EC are highlighted in red.