【摘要】 RNA解旋酶DEAD-box(DDX)蛋白家族是目前已知的最大解旋酶家族,可以解旋RNA或者解离蛋白RNA复合物;其中DDX1蛋白参与多种细胞功能,在mRNA/rRNA加工及衰减、病毒复制及转录、激素代谢以及肿瘤发生发展等各方面发挥着重要作用.但目前有关DDX1如何识别、结合和解旋RNA,如何在各种生理病理过程中发挥功能的分子基础仍然不清楚,其核心功能区的结构尚未解析.本研究成功地在大肠杆菌中重组表达和纯化了人源DDX1蛋白,获得了全长DDX1及多个不同长度截短体(或结构域)蛋白.结合动态光散射(DLS)分析发现DDX1的N端解旋酶ATP结合区结构稳定,状态均一;C末端结构域可能介导与其他蛋白相互作用,具动态变化并容易聚集.X光小角散射实验表明,溶液中DDX1全长蛋白为单体且构象均一.二级结构预测和三维结构模型构建表明DDX1具有经典的DEAD解旋酶家族特征.更多还原

【Abstract】 The DEAD-box protein family is the largest known helicase family,which can unwind RNA or dissociate RNA-protein complex.Among them,DDX1 is involved in a variety of cellular functions and plays essential roles in the mature and decay of mRNA/rRNA, replication and transcription of viruses, hormone and cancer metabolism.However,the detailed mechanism that how DDX1 recognizes and unwinds RNA, and plays critical roles in RNA metabolism keeps unclear.The structure of its core area has not been resolved.In this study,the recombinant DDX1 fragments were expressed in E.coli and purified successfully.The DLS analysis showed that the Nterminal helicase ATP binding region of DDX1 has stable conformation, whereas the C-terminal region is quite dynamic and prone to aggregate.The full-length DDX1 was monomer and stable in solution judged by the gelfiltration and SAXS analysis.Moreover,the human DDX1 exhibits typical structural property of RNA helicase family using SWISS-Model prediction server.更多还原