CASCADE REGULATION OF NIF GENE-EXPRESSION IN RHIZOBIUM-MELILOTI
CASCADE REGULATION OF NIF GENE-EXPRESSION IN RHIZOBIUM-MELILOTI
复制标题
DOI：
10.1016/s0092-8674(88)80012-6
复制
发表时间：
1988-08-26
期刊：
影响因子：
64.5
通讯作者：
KAHN, D
中科院分区：
文献类型：
--
作者：
DAVID, M;DAVERAN, ML;KAHN, D
我们报告的发现两个基因从苜蓿根瘤菌，fixL和fixJ，这是不同的固氮（nif和fix）基因的共生表达的正调节器。nif基因调控显示由级联反应组成：fixLJ基因激活nifA，nifA又激活nifHDK和fixABCX。在自由生活的微好氧培养物中可以诱导出生活nifA、fixN。苜蓿，表明氧在NIF和FIX基因调控中的主要生理作用。fixN和nifA的微需氧表达取决于fixL和fixJ。FixL和FixJ蛋白属于在原核生物中广泛分布的双组分调节系统家族，并且对细胞环境有响应。我们提出FixL具有跨膜蛋白的特征，它感知环境信号并将其转导给nif和fix基因的转录激活因子FixJ。
We report the discovery of two genes from Rhizobium meliltoti, fixL and fixJ, which are positive regulators of symbiotic expression of diverse nitrogen fixation (nif and fix) genes. nif gene regulation is shown to consist of a cascade: the fixLJ genes activate nifA, which in turn activates nifHDK and fixABCX. Life nifA, fixN can be induced in free-living microaerobic cultures of R. meliloti, indicating a major physiological role for oxygen in nif and fix gene regulation. Microaerobic expression of fixN and nifA depends on fixL and fixJ. The FixL and FixJ proteins belong to a family of two-component regulatory systems widely spread among prokaryotes and responsive to the cell environment. We proposed that FixL, which has features of a transmembrane protein, senses an environmental signal and transduces it to FixJ, a transcriptional activator of nif and fix genes.