RNA Polymerase Sigma Factors in Streptococcus pyogenes

化脓性链球菌（A群链球菌或GAS）是一种重要而常见的人类病原体。它引起的疾病范围很广，从自限性皮肤和咽喉感染，然而，有可能产生严重的后遗症，包括风湿性心脏病、急性肾小球肾炎和可能的儿童神经心理障碍，到严重的侵袭性疾病，如肌炎和链球菌中毒性休克综合征。由于单个GAS菌株似乎能够引起大多数或所有这些疾病，因此对宿主内特定环境差异的GAS基因表达的调节可能是决定感染过程的关键。在此，我们提出了一种新的方法，通过表征在不同条件下转录基因所需的新的RNA聚合酶（RNAP）次级sigma因子及其调控基因的表征，来更多地了解GAS中基因表达的控制。

Streptococcus pyogenes (the group A streptococcus or GAS) is an important and common human pathogen. The diseases it causes range from self-limiting skin and throat infections, with, however, the potential for serious sequelae including rheumatic heart disease, acute glomerulonephritis, and possibly pediatric neuropsychological disorders, to severe invasive diseases like myositis and streptococcal toxic shock syndrome. Since single strains of the GAS seem to be able to cause most or all of these diseases, regulation of the expression of GAS genes in response to specific environmental differences within the host is probably key in determining the course of the infectious process. We propose here a new approach to learn more about control of gene expression in the GAS by the characterization of a new RNA polymerase (RNAP) secondary sigma factor needed to transcribe genes under different conditions and the characterization of the genes it regulates.