Molecular analysis of the chromosomal region encoding the nifA and nifB genes of Acetobacter diazotrophicus
Molecular analysis of the chromosomal region encoding the nifA and nifB genes of Acetobacter diazotrophicus
复制标题
固氮醋杆菌 nifA 和 nifB 基因染色体区域的分子分析
DOI：
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
D. Meletzus
中科院分区：
文献类型：
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作者：
K. Teixeira;M. Wülling;T. Morgan;R. Galler;E. Zellermann;J. Baldani;C. Kennedy;D. Meletzus
固氮醋杆菌 nifA 基因是通过其将 Nif+ 表型恢复到 Azotobacter vinelandii 的 nifA 突变体的能力而分离的。测序结果显示，nifA基因位于nifB基因的上游且相邻，两者以相同方向转录，但独立于不同的启动子。 nifB 基因的 3' 端位于固氮酶结构基因簇 nifHDK 上游约 2.5 kb 处。推导的固氮固氮菌 nifA 和 nifB 基因产物的氨基酸序列分别与 Azorhizobium caulinodans 和 Rhodobacter capsulatus 的 NifA 和 NifB 蛋白最相似。在暴露于高水平铵的培养物中，固氮放线菌 nifA 表达受到抑制，而氧气显然没有影响。氧和铵均阻止 nifB 报告菌株的表达，这与铵抑制 nifA 表达的观察结果一致，并表明固氮固氮菌 NifA 活性与其他变形菌 α 组固氮菌一样受到氧的抑制。
The Acetobacter diazotrophicus nifA gene was isolated by its ability to restore a Nif+ phenotype to a nifA mutant of Azotobacter vinelandii. Sequencing revealed that the nifA gene was upstream and adjacent to the nifB gene and both are transcribed in the same direction but independently from different promoters. The 3′ end of the nifB gene was located approximately 2.5 kb upstream of the nitrogenase structural gene cluster, nifHDK. The deduced amino acid sequences of the A. diazotrophicus nifA and nifB gene products were most similar to the NifA and NifB proteins of Azorhizobium caulinodans and Rhodobacter capsulatus, respectively. A. diazotrophicus nifA expression was repressed in cultures exposed to high levels of ammonium while oxygen apparently had no influence. Both oxygen and ammonium prevented expression of a nifB-reporter strain, consistent with the observation that ammonium repressed nifA expression, and indicating that A. diazotrophicus NifA activity is inhibited by oxygen as in other Proteobacterial α group diazotrophs.
影响因子：
3.5
作者：
METCALF, WW;WANNER, BL
通讯作者：
WANNER, BL