Activation of the glnA, glnK, and nac promoters as Escherichia coli undergoes the transition from nitrogen excess growth to nitrogen starvation
Activation of the glnA, glnK, and nac promoters as Escherichia coli undergoes the transition from nitrogen excess growth to nitrogen starvation
复制标题
DOI：
10.1128/jb.184.19.5358-5363.2002
复制
发表时间：
2002-10-01
影响因子：
3.2
通讯作者：
Ninfa, AJ
中科院分区：
文献类型：
--
作者：
Atkinson, MR;Blauwkamp, TA;Ninfa, AJ
大肠杆菌Ntr调节子的氮调节基因和操纵子被增强子结合转录激活因子NRI similar to P（NtrCsimilar to P）激活。在这里，我们研究了激活的glnA，glnK，和nac启动子作为细胞经历的过渡，从生长氨氮饥饿，并检查在此过渡期间NRI的扩增。结果表明，随着细胞变得缺乏氨，NRI的浓度增加，同时具有比glnA效率更低的增强子的Ntr基因的激活。当大肠杆菌在低浓度的氨与作为氮源的精氨酸的组合中生长时，获得二次生长模式，这与除了glnA之外的Ntr基因仅在NRI浓度扩增时被激活的假设一致。
The nitrogen-regulated genes and operons of the Ntr regulon of Escherichia coli are activated by the enhancer-binding transcriptional activator NRIsimilar toP (NtrCsimilar toP). Here, we examined the activation of the glnA, glnK, and nac promoters as cells undergo the transition from growth on ammonia to nitrogen starvation and examined the amplification of NRI during this transition. The results indicate that the concentration of NRI is increased as cells become starved for ammonia, concurrent with the activation of Ntr genes that have less-efficient enhancers than does glnA. A diauxic growth pattern was obtained when E, coli was grown on a low concentration of ammonia in combination with arginine as a nitrogen source, consistent with the hypothesis that Ntr genes other than glnA become activated only upon amplification of the NRI concentration.