Role and regulation of the Shigella flexneri sit and MntH systems.
Role and regulation of the Shigella flexneri sit and MntH systems.
复制标题
福氏志贺氏菌和 MntH 系统的作用和调节。
DOI：
10.1128/iai.00562-06
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
Warner,Lisa
中科院分区：
文献类型：
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作者：
Runyen-Janecky,Laura;Dazenski,Ellyn;Hawkins,Stephanie;Warner,Lisa
福氏志贺菌至少具有两个推定的高亲和力锰获取系统，SitABCD和MntH。在福氏志贺菌中构建了编码这两种系统组分的基因突变。ThesitA mntH突变体表现出减少的增长，相对于野生型，在Luria肉汤（L肉汤）含有二价金属螯合剂亚乙基二氨基-O-二羟基苯基乙酸，并添加铁或锰恢复生长的野生型菌株的水平。虽然thesitA mntH突变体是没有缺陷的生存暴露于超氧化物发生器，它是有缺陷的生存暴露于过氧化氢。ThesitAmntH突变体在Henle细胞单层上形成野生型斑块，但在活化的巨噬细胞系中存活能力降低。表达S.志贺氏菌在Henle细胞中表达的flexneri situ和mntH启动子的活性高于在L肉汤中表达的。无论是铁或锰，抑制这两个thesitandmntH启动子的表达，这种抑制是部分依赖于Fur和MntR，分别。ThemntH启动子，而不是thesitpromoter，在过氧化氢的存在下表现出OxyR依赖的诱导。
Shigella flexneripossesses at least two putative high-affinity manganese acquisition systems, SitABCD and MntH. Mutations in the genes encoding the components of both of these systems were constructed inS. flexneri. ThesitA mntHmutant showed reduced growth, relative to the wild type, in Luria broth (L broth) containing the divalent metal chelator ethylene diamino-o-dihydroxyphenyl acetic acid, and the addition of either iron or manganese restored growth to the level of the wild-type strain. Although thesitA mntHmutant was not defective in surviving exposure to superoxide generators, it was defective in surviving exposure to hydrogen peroxide. ThesitA mntHmutant formed wild-type plaques on Henle cell monolayers but had a reduced ability to survive in activated macrophage lines. Expression of theS. flexneri sitandmntHpromoters was higher whenShigellawas in Henle cells than when it was in L broth. Expression of both thesitandmntHpromoters was repressed by either iron or manganese, and this repression was partially dependent upon Fur and MntR, respectively. ThemntHpromoter, but not thesitpromoter, exhibited OxyR-dependent induction in the presence of hydrogen peroxide.