Fig. 1. Structures of MuV L–P complex.

a Diagram of MuV L and P domains. RdRp, PRNTase, Hinge regions (Hinge-1&2), CD, MTase, and CTD of L are colored in blue, green, tan, gold, orange, and crimson, respectively. NTD, OD, Linker region 2 (Linker2), and CTD of P are colored in light gray, purple, violet red, and magenta, respectively. The same color strategy is used throughout the manuscript unless specified. CR I–VI: six conserved regions in L. b Cryo-EM density maps of MuV L_integral–P (EMD-35864). NTP entry, genomic RNA (gRNA) entry, and gRNA exit are circled. c Atomic models of MuV L_integral–P (PDB ID 8IZL). d Cryo-EM density map of MuV L_body–P (EMD-37964). e Atomic model of MuV L_body–P (PDB ID 8X01). Maps in (b, d) are the composite cryo-EM maps of MuV L_integral–P and L_body–P to improve the interpretability, after post-processing in DeepEMhancer⁶⁹. These are also utilized for other figure preparation. Models in (c, e) are the composite atomic models of MuV L_integral–P and L_body–P via rigid body docking of individual models into their respective composite cryo-EM maps, which are B-factor sharpened.