大肠杆菌硫氧还蛋白DsbA调控T1样噬菌体复制的分子基础与作用机制

DsbA为大肠杆菌周质空间硫氧还蛋白家族成员，在维持蛋白功能中发挥重要作用。项目组发现，缺失dsbA的大肠杆菌生长特征不变，也不影响T1样噬菌体的吸附和基因组DNA的注入，但子代噬菌体数量显著下降。为阐明DsbA影响噬菌体复制的分子机制，本项目聚焦细菌DsbA及其互作分子，分析影响噬菌体复制的DsbA活性位点；明确DsbA调控噬菌体复制的关键环节；解析DsbA通过跨膜蛋白激活细菌转录调节因子、启动相关基因转录和翻译，进而影响噬菌体生物合成和子代组装的调控网络；揭示DsbA通过修饰Holin触发Lysin裂解肽聚糖促进噬菌体释放的机制。最终系统阐明大肠杆菌DsbA操控T1样噬菌体复制的分子基础，诠释DsbA缺失所致噬菌体耐受的调控机制。选题具有开创性，研究结果将拓展细菌与噬菌体互作的新理论，为开发耐药性大肠杆菌的高效噬菌体治疗制剂、减少抗生素使用、维护绿色生态环境等提供科学依据和创新策略。

DsbA is a thioredoxin in the periplasm of E. coli cells and plays an important role in maintaining protein functions. Our preliminary data showed that the growth kinetics of dsbA deficiency E. coli were similar to wild type strains and did not affect the adsorption and DNA injection of T1-like phage, but the numbers of the offspring phage were decreased significantly. To elucidate the molecular mechanism of DsbA regulating phage replication, this project focuses on the E. coli Dsb system, locating on the functioning cysteine activity center. The effect of multigene synergy of Dsb family on phage replication will be studied. To reveal the key steps of DsbA regulating phage replication, the different functional transmembrane proteins that may directly interact with DsbA and their key interaction molecules and regulatory pathways will be explored. The mechanism of DsbA promoting the release of phage by activating the endolysin to lysate peptide polysaccharides via triggering holin will be demonstrated. A regulatory network for phage replication that relies on bacteria DsbA will be consequently constructed, and the molecular mechanism of E. coli DsbA regulating phage replication and phage tolerance induced by DsbA deficiency will be systemically elucidated. The results will enrich the scientific theory of interaction between bacteria and phage, and provide scientific basis and innovative strategies for synthesizing or modifying phages, developing phage therapeutic agents for drug-resistant E. coli. This will promote the reduction of antibiotic use and improve the green ecological balance.