Analysis of a Shigella dysenteriae Fe regulated promoter

描述(申请人提供)：每年有数百万例志贺氏菌引起的志贺氏菌病病例报告。志贺氏菌属必须获得所有必需的营养，包括铁(Fe)，才能在人类宿主内生存并引发疾病。微环境中铁的存在影响志贺氏菌获取铁所需其产物的基因的表达(Mills和Payne，1995；Mills和Payne，1997)。铁调控基因表达的机制尚不完全清楚。本研究旨在研究外膜血红素受体基因Shua对铁影响表达的调控机制，该基因的功能对痢疾链霉菌利用血红素作为营养铁源具有重要作用。本研究的具体目的是：1)确定Shua基因表达的启动子；2)研究铁调控Shua基因表达的机制；3)分析血红素对Shua基因表达的影响。完全了解铁的获取，包括涉及的基因和蛋白质，将导致对志贺氏菌所采用的策略的更全面的理解。以求在人类宿主内生存和繁殖。

DESCRIPTION (provided by applicant): Millions of cases of shigellosis, caused by the Shigella species, are reported annually. Shigella spp. must acquire all essential nutrients, including iron (Fe), to survive and cause disease within the human host. The presence of Fe within the microenvironment influences the expression of genes whose products are required for Fe acquisition by Shigella (Mills and Payne, 1995; Mills and Payne, 1997). The mechanisms governing Fe regulated gene expression are not fully understood. This proposal aims to characterize the mechanisms controlling the Fe influenced expression of shuA, a gene encoding an outer membrane heme receptor whose function is essential for the utilization of heme as a source of nutrient Fe by S. dysenteriae. The specific aims set forth in this proposal are to: 1) characterize the promoter controlling expression of S. dysenteriae shuA; 2) investigate the mechanisms controlling the Fe-regulated expression of shuA; and 3) analyze the influence of heme on the expression of shuA. A complete understanding of Fe acquisition, including the genes and proteins involved, will lead to a fuller appreciation of the strategies employed by Shigella spp. for survival and proliferation within the human host.