Structures of the mumps virus polymerase complex via cryo-electron microscopy.
Li, T., Liu, M., Gu, Z., Su, X., Liu, Y., Lin, J., Zhang, Y., Shen, Q.T.(2024) Nat Commun 15: 4189-4189
- PubMed: 38760379 
- DOI: https://doi.org/10.1038/s41467-024-48389-9
- Primary Citation of Related Structures:  
8IZL, 8X01, 8YXL, 8YXM, 8YXO, 8YXP, 8YXR - PubMed Abstract: 
The viral polymerase complex, comprising the large protein (L) and phosphoprotein (P), is crucial for both genome replication and transcription in non-segmented negative-strand RNA viruses (nsNSVs), while structures corresponding to these activities remain obscure. Here, we resolved two L-P complex conformations from the mumps virus (MuV), a typical member of nsNSVs, via cryogenic-electron microscopy. One conformation presents all five domains of L forming a continuous RNA tunnel to the methyltransferase domain (MTase), preferably as a transcription state. The other conformation has the appendage averaged out, which is inaccessible to MTase. In both conformations, parallel P tetramers are revealed around MuV L, which, together with structures of other nsNSVs, demonstrates the diverse origins of the L-binding X domain of P. Our study links varying structures of nsNSV polymerase complexes with genome replication and transcription and points to a sliding model for polymerase complexes to advance along the RNA templates.
Organizational Affiliation: 
School of Life Sciences, Department of Chemical Biology, Southern University of Science and Technology, Shenzhen, 518055, China.