The influenza virus polymerase uses capped RNA primers to initiate transcription, and a combination of terminal and internal de novo initiations for the two-step replication process by binding the conserved viral genomic RNA (vRNA) or complementary RNA (cRNA) promoter. Here, we determined the apo and promoter-bound influenza D polymerase structures using cryo-electron microscopy and found the polymerase has an evolutionarily conserved stable core structure with inherently flexible peripheral domains. Strikingly, two conformations (mode A and B) of the vRNA promoter were observed where the 3'-vRNA end can bind at two different sites, whereas the cRNA promoter only binds in the mode B conformation. Functional studies confirmed the critical role of the mode B conformation for vRNA synthesis via the intermediate cRNA but not for cRNA production, which is mainly regulated by the mode A conformation. Both conformations participate in the regulation of the transcription process. This work advances our understanding of the regulatory mechanisms for the synthesis of different RNA species by influenza virus polymerase and opens new opportunities for antiviral drug design.
Organizational Affiliation:
CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
Institute of Physical Science and Information Technology, Anhui University, Hefei, China.
Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China.
Research Network of Immunity and Health, Beijing Institute of Life Sciences, Chinese Academy of Sciences, Beijing, China.
National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
Department of Biology, Southern University of Science and Technology, Shenzhen, China.
CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
Shenzhen Key Laboratory of Pathogen and Immunity, Shenzhen Third People's Hospital, Shenzhen, China.
CAS Center for Influenza Research and Early-warning, CAS-TWAS Center of Excellence for Emerging Infectious Disease, Chinese Academy of Sciences, Beijing, China.
MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China. gaof@im.ac.cn.
Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China. gaof@im.ac.cn.
Research Network of Immunity and Health, Beijing Institute of Life Sciences, Chinese Academy of Sciences, Beijing, China. gaof@im.ac.cn.
Shenzhen Key Laboratory of Pathogen and Immunity, Shenzhen Third People's Hospital, Shenzhen, China. gaof@im.ac.cn.
CAS Center for Influenza Research and Early-warning, CAS-TWAS Center of Excellence for Emerging Infectious Disease, Chinese Academy of Sciences, Beijing, China. gaof@im.ac.cn.
National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China. gaof@im.ac.cn.
CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China. shiyi@im.ac.cn.
Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China. shiyi@im.ac.cn.
Shenzhen Key Laboratory of Pathogen and Immunity, Shenzhen Third People's Hospital, Shenzhen, China. shiyi@im.ac.cn.
CAS Center for Influenza Research and Early-warning, CAS-TWAS Center of Excellence for Emerging Infectious Disease, Chinese Academy of Sciences, Beijing, China. shiyi@im.ac.cn.
College of Basic Medicine, Jilin University, Changchun, China. shiyi@im.ac.cn.
Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing General Hospital, University of Chinese Academy of Sciences, Chongqing, China. shiyi@im.ac.cn.
Download Mendeley
