Download MendeleyStructural basis for the concurrence of template recycling and RNA capping in SARS-CoV-2.
Yan, L., Huang, Y., Liu, Y., Ge, J., Gao, S., Tan, L., Liu, L., Liu, Z., Ye, S., Wang, J., Xiong, J., Zhou, Y., Zhao, H., Zhao, X., Guddat, L.W., Gao, Y., Zhu, L., Rao, Z., Lou, Z.(2025) Cell 188: 7194-7205.e10
- PubMed: 41130208
- DOI: https://doi.org/10.1016/j.cell.2025.09.022
- Primary Citation of Related Structures:
8XCH, 9IMK, 9IMM - PubMed Abstract:
In the SARS-CoV-2 replication-transcription complex (RTC), the nascent template-product duplex is unwound into a template strand for recycling and a product strand that needs to be capped. Here, we determined structures of the SARS-CoV-2 RTC in the pre- and post-capping initiation (CI) states. In the pre-CI state, the RTC has a dimer-of-dimeric architecture (ddRTC). The upstream RNA duplex in one RTC is reciprocally unwound by a helicase in a head-to-head-positioned RTC in the 3'-5' direction. The helicases bind either ADP or ADP⋅P i in their ATP-binding pockets, suggesting a mechanism for ATP-hydrolysis-driven unwinding. In the post-CI state, the binding of nsp9 to the nsp12 nidovirus RdRp-associated nucleotidyltransferase (NiRAN) disrupts the ddRTC. The N terminus of nsp9 and the triphosphorylated 5' end of the product strand co-localize in NiRAN's catalytic site, exhibiting the state prior to nsp9 RNAylation for capping. These results provide an insight into the concurrence of template recycling and RNA capping in the SARS-CoV-2 RTC.
- MOE Key Laboratory of Protein Science, School of Basic Medical Sciences, Tsinghua University, Beijing 100084, China; Guangzhou National Laboratory, Guangzhou 510005, China; State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China.
Organizational Affiliation:
