Small RNA regualtors of the B. anthracis plasmid pXO1

描述（申请人提供）：炭疽芽孢杆菌是炭疽的病原体，是生物防御a类优先病原体。野生型炭疽杆菌携带两种质粒，pXO1和pXO2，这两种质粒都是产生疾病所绝对需要的。pXO1编码炭疽毒素成分，pXO2编码聚d -谷氨酸胶囊生产基因，两者都是必不可少的毒力因子。对这些质粒的研究大多集中在毒素和荚膜基因及其调控上，但对质粒本身的生物学特性知之甚少。本提案中描述的实验旨在鉴定和表征可能参与pXO1质粒编码功能调节的小rna。最初的重点将集中在质粒维持功能，包括复制和稳定遗传所需的功能，因为小rna经常在其他系统中调节这些功能。然而，在其他细菌中的研究已经清楚地表明，rna介导的调控在原核生物系统中一直被低估，并且可能在调控回路中发挥比以前想象的更重要的作用。正因为如此，研究小rna在控制质粒维持中的作用的方法将扩大到筛选整个质粒中可能介导质粒功能的其他调节方面的rna，包括毒素的产生。在潜在的调控rna被定位后，它们的靶标将被识别，它们在调控这些靶标中的作用将被确定。将进行详细的研究以确定这些小rna调控的分子机制。希望通过鉴定RNA控制的质粒功能靶标，可以开发出干扰这些功能的化合物，从而“解毒”生物体。此外，该系统中RNA调控规律的确定将为进一步研究可能编码在pXO2或炭疽芽孢杆菌染色体上的调控RNA铺平道路。

DESCRIPTION (provided by applicant): Bacillus anthracis is the causative agent of anthrax and a biodefense category A priority pathogen. Wild type B. anthracis carries two plasmids, pXO1 and pXO2, both of which are absolutely required for production of disease. pXO1 encodes the components of the anthrax toxin and pXO2 encodes the genes for production of the poly-D-glutamic acid capsule, both of which are essential virulence factors. Most of the research on these plasmids has focused on the toxin and capsule genes and their regulation, but little is known about the biology of the plasmids themselves. The experiments described in this proposal are designed to identify and characterize small RNAs that may be involved in regulation of pXO1 plasmid-encoded functions. Emphasis will initially focus on plasmid maintenance functions, including those required for replication and stable inheritance, since small RNAs frequently regulate these functions in other systems. However, work in other bacteria has clearly shown that RNA-mediated regulation has been underappreciated in prokaryotic systems and probably plays a much more important role in regulatory circuits than previously imagined. Because of this, procedures developed to examine the role of small RNAs in controlling plasmid maintenance will be expanded to screen the entire plasmid for RNAs that may mediate other regulatory aspects of plasmid function, including toxin production. After potential regulatory RNAs have been located, their targets will be identified and their role in regulating those targets will be determined. Detailed studies will be conducted to determine the molecular mechanisms of regulation of these small RNAs. It is hoped that by identifying RNA controlled targets of plasmid function, compounds can be developed to interfere with these functions and thereby "detoxify" the organism. Furthermore, determination of the rules of RNA regulation in this system will pave the way for further study of regulatory RNAs that may be encoded on pXO2 or the B. anthracis chromsome.