解旋酶是参与核酸代谢过程的一类重要功能蛋白，近年来发现病毒编码的解旋酶在病毒基因组复制中具有重要的作用，已成为有效的抗病毒药物靶标。黄病毒NS3基因编码解旋酶，它既可与病毒基因组RNA相互作用，又与病毒复制过程的主要功能蛋白互作，在组装病毒复制复合体中发挥重要作用。然而目前针对解旋酶在起始黄病毒复制中的机制研究非常有限，许多关键的细节问题不明。本项目拟以乙型脑炎病毒解旋酶为对象，开展解旋酶与RNA相互作用机制的研究，阐明解旋酶识别基因组RNA的序列和结构特征，揭示解旋酶在基因组的载入机制；筛选并鉴定与NS3解旋酶互作的病毒蛋白，阐明互作蛋白的排列方式和互作的关键位点；筛选并鉴定细胞中与NS3解旋酶互作的蛋白质，分析互作对解旋酶活性及病毒复制的影响，揭示细胞蛋白通过NS3解旋酶对病毒复制进行调控的机制。本项目研究将揭示NS3解旋酶参与JEV基因组复制起始的机制，为抗病毒治疗提供新的策略。

Helicase is one of important proteins which participating in the metabolism of nucleic acid. The viral helicase is associated with genomic replication and has become an potential target of anti-viral drugs in recent years. Helicase of Japanese encephalitis virus (JEV), encoded by NS3 gene, can not only binding viral genomic RNA but also interact with other viral replicases, and thus have important roles in assembly of replication complex. However, the roles of NS3 helicase in initiation of flavivirus replication were known very limited, many crucial details were unclear. In this project, our studies will focus on the interaction between NS3 helicase and viral genomic RNA, viral proteins, and cellular proteins. The characteristic of helicase recognized RNA sequence or secondary structure in JEV genome will be resolved by determining binding capability of different fragments of 3'NCR with NS3 helicase; This project will also screen and identify the viral proteins that interact with NS3 helicase, and then elucidate the interaction pattern and crucial amino acids; By screening and identifying the cellular proteins that interact with NS3 helicase, findind the influence of interaction on helicase activity and virus replication, this project will reveal the components that can regulate virus replication in cells. Altogether our studies will explain how the helicase participate in JEV replication complex assemble and raise new strategies for antiviral therapy.