新型冠状病毒（SARS-CoV-2）属于冠状病毒属，是一种正义单链RNA病毒，是导致新冠病毒肺炎（COVID-19）暴发的病原体。RNA病毒编码的解旋酶通过促进病毒RNA的正确折叠和复制，在病毒的生命周期中发挥着重要作用。冠状病毒属nsp13蛋白是经典解旋酶。申请人的前期研究表明新型冠状病毒nsp13蛋白是RNA解旋酶，具有NTPase活性和解旋活性。以nsp13蛋白NTPase活性和解旋活性作为靶标进行抗病毒药物研究，我们发现含铋复合物能有效抑制nsp13蛋白的这两种活性。据此，本项目将进一步研究nsp13蛋白NTPase活性和解旋活性对新冠病毒复制的作用，阐明含铋复合物抑制nsp13蛋白两种酶活性的作用机制，最终确定含铋复合物对新冠病毒复制的影响及作用机制。本项目将完善对新冠病毒复制机制及抗病毒药物的认识，将对新冠病毒抗病毒治疗提供借鉴意义。

SARS-coronavirus-2 (SARS-CoV-2), the causative pathogen of COVID-19, is a positive-sense single-stranded RNA virus belonging to the family Coronaviriade. For RNA viruses, virus-encoded RNA helicases have long been recognized to play pivotal roles during viral life cycles by facilitating the correct folding and replication of viral RNAs. The coronavirus nsp13 is a classic helicase. The applicant's previous studies showed that the SARS-CoV-2 nsp13 is an RNA helicase, has NTPase and helix unwinding activities. Using the NTPase and helix unwinding activities of nsp13 as a target for researching antiviral drug, we found that some bismuth salts compounds (on the market) can effectively inhibit the NTPase and helix unwinding activities of nsp13. Therefore, this project will further study the importance of the NTPase and helix unwinding activities of nsp13 to virus replication, clarify the mechanism of bismuth salts compounds inhibiting the two activities of nsp13, and finally determine the influence and mechanism of bismuth salts compounds on SARS-CoV-2 replication. This project will improve the understanding of SARS-CoV-2 replication mechanism and antiviral drugs, and provide reference for COVID-19 clinical treatment.