部分革兰氏阴性菌胞外功能sigma因子结构与调控铁离子的利用机制

发布时间：2018-04-14 15:30

本文选题：胞外功能σ因子 + 铁离子调控　；参考：《中国生物化学与分子生物学报》2017年02期

【摘要】：铁离子是大多数细菌生存所必需的一种营养物质,但摄入过多的铁离子也会对细菌造成损伤。因此,细菌对铁离子的摄取受到严格调控。革兰氏阴性菌对铁离子的摄取主要受Fur(ferric uptake regulator)蛋白和σ(sigma)因子的调控。σ因子是RNA聚合酶的可解离亚基,能使RNA聚合酶结合到基因的启动子区域,从而引起基因转录。因此,σ因子在原核生物转录起始过程中必不可少。细菌中存在多种σ因子,参与铁离子调控的σ因子即是胞外功能σ因子(extra-cytoplasmic function sigma factor,ECF sigma factor)。通常,胞外功能σ因子活性可被抗σ因子(anti-sigma factor)抑制。当受到外界环境信号的刺激,σ因子与抗σ因子解离,从而使σ因子活化并结合RNA聚合酶核心酶形成全酶,引起目的基因的转录。本文将就胞外功能σ因子在σ因子家族中的分类地位、结构特点以及对3价铁离子和血红素的转运调控机制作一综述。
[Abstract]:Iron ion is a nutrient necessary for the survival of most bacteria, but excessive intake of iron ion can also damage bacteria.Therefore, the uptake of iron ions by bacteria is strictly regulated.The uptake of iron ions by Gram-negative bacteria is mainly regulated by Fur(ferric uptake regulator protein and 蟽 sigma) factor, which is the dissociable subunit of RNA polymerase, which can bind RNA polymerase to the promoter region of the gene and induce gene transcription.Therefore, 蟽 factor is essential in the initiation of prokaryote transcription.There are many kinds of 蟽 factors in bacteria. The 蟽 factor involved in the regulation of iron ion is extra-cytoplasmic function sigma factor of extracellular sigma factor.In general, the activity of extracellular function 蟽 factor can be inhibited by anti sigma factor.When stimulated by external environmental signals, 蟽 factor dissociates from anti 蟽 factor, which activates 蟽 factor and binds to RNA polymerase core enzyme to form a whole enzyme, which causes transcription of the target gene.In this paper, the taxonomic position, structural characteristics of extracellular function 蟽 factor in the 蟽 factor family and the mechanism of regulating the transport of trivalent iron ions and heme are reviewed.
【作者单位】：四川农业大学动物医学院禽病防治中心;四川农业大学动物医学院预防兽医研究所;四川省动物疫病与人类健康四川省重点实验室;
【基金】：四川省国际科技交流合作项目(No.2016HH0052) 国家自然科学基金青年科学基金项目(No.31302131) 教育部博士点基金(新教师类)(No.20135103120006)资助~~
【分类号】：R378

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