Nitrogen regulation of synthesis of the high affinity methylammonium transport system of Escherichia coli.
Nitrogen regulation of synthesis of the high affinity methylammonium transport system of Escherichia coli.
复制标题
大肠杆菌高亲和力甲基铵转运系统合成的氮调节。
DOI：
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发表时间：
1984
期刊：
影响因子：
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通讯作者：
F. Bastarrachea
中科院分区：
文献类型：
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作者：
L. Servín;F. Bastarrachea
14CH3NH+3（甲基铵）的摄取测量作为探针的NH+4运输在完整的大肠杆菌细胞和衍生物受损的NTR调节系统。结果表明，高亲和力14 CH 3 NH +3转运系统的表达（a）需要从头多肽合成，（B）在氮限制下被glnG和glnF调节产物激活，（c）在氮过量下被glnL产物抑制。由于其携带gltB31突变而缺乏谷氨酸合酶活性的细胞不能激活14CH3NH+3转运的合成。这可以解释携带gltB突变的细胞不能在低浓度的NH+4上生长。
Uptake of 14CH3NH+3 (methylammonium) was measured as a probe of NH+4 transport in intact Escherichia coli cells and derivatives impaired in the Ntr regulatory system. The results suggest that expression of the high affinity 14CH3NH+3 transport system (a) requires de novo polypeptide synthesis, (b) is activated by the glnG and glnF regulatory products under nitrogen limitation, and (c) is repressed under nitrogen excess by the glnL product. Cells deficient in glutamate synthase activity by virtue of their harbouring the gltB31 mutation were unable to activate synthesis of 14CH3NH+3 transport. This could explain the inability of cells carrying gltB mutations to grow on low concentrations of NH+4.