胁迫应答对于结核分枝杆菌的感染和在宿主体内的生存十分关键，然而相关的分子机制尚不清楚。拟核结合蛋白是一类通过结合并改变染色体结构调控基因表达的全局调控蛋白。申请人团队前期研究发现结核分枝杆菌未知功能蛋白Rv0047c具有拟核结合蛋白特征，并且表达该蛋白能显著增加细菌的药物抗性和抗氧化能力。本项目将结合遗传学和分子生物学技术手段系统研究Rv0047c与核酸的结合特征及其对结核分枝杆菌生理调控的分子机制。首先采用EMSA和原子力显微镜等技术手段研究Rv0047c与核酸的相互作用机制；进而通过监测不同环境胁迫下rv0047c基因异常表达菌株的生长变化情况，鉴定其生理功能；最后，利用全基因组芯片分析、RT-PCR及ChIP技术鉴定Rv0047c所调控的靶基因。研究结果将阐明拟核结合蛋白Rv0047c的生理功能及其调控结核分枝杆菌胁迫应答的分子机制。

Stress response is essential for infection and survival of Mycobacterium tuberculosis in the host. However, our understanding on underlying molecular mechnisms is still largely incomplete. Nucleoid-associated proteins,a global gene regulation proteins, regulate gene expression by organizing and condensing bacterial chromosome. In previous studies, we found a hypothesis protein Rv0047c of Mycobacterium tuberculosis exhibited several characteristics similar to nucleoid-associated protein. In addition, over-expression of Rv0047c significantly increased resistance of Mycobacterium tuberculosis to antibiotics and H2O2. This project will focus on systematically identifying DNA-binding characteristics, physiological roles and regulation mechanisms of Rv0047c in Mycobacterium tuberculosis through integrating genetics and molecular biology experimental methods. First, DNA-binding characteristics of Rv0047c will be studied by EMSA assay and atomic force microscope observation. Second, the physiological roles of Rv0047c in Mycobacterium tuberculosis will be analyzed by detecting bacterial-growth curve and morphology of rv0047c knockout and over-expression recombinant strains under various environmental stimuli. Third, target genes regulated by Rv0047c will be identified by microarray analysis, RT-PCR and ChIP experiment to explore the regulation pathways. The results will elucidate the roles of a new nucleoid-associated protein Rv0047c and provide insights into the nucleoid-associated protein mediated stress response mechanisms of mycobacteria.