A Rhizobium meliloti symbiotic regulatory gene
A Rhizobium meliloti symbiotic regulatory gene
复制标题
苜蓿根瘤菌共生调控基因
DOI：
10.1016/0092-8674(84)90053-9
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发表时间：
1984
期刊：
影响因子：
64.5
通讯作者：
F. Ausubel
中科院分区：
文献类型：
--
作者：
W. Szeto;J. Zimmerman;V. Sundaresan;F. Ausubel
我们已经确定了苜蓿根瘤菌的两个紧密相连的共生操纵子，固氮酶操纵子（nifHDK基因）和“P2”操纵子的表达所需的调控基因。该调控基因定位于nif/fDK操纵子上游5.5kb的1.8kb区域。调节基因是MffDK和P2 mRNA积累和R.苜蓿nifH-/acZ融合质粒在共生生长过程中的表达。MH启动子和P2启动子可在自由存活的R.含有组成型产生大肠杆菌nfrC（g/nG）或肺炎克雷伯氏菌nifA调节基因产物的质粒的苜蓿属植物。中华民国苜蓿调节基因与E. colinfrG（glnG），对K. pneumoniae nifA DNA。我们的研究结果表明，R.苜蓿调节基因是一个正转录激活因子，与苜蓿根瘤菌的生长有关。pneumoniae nif调控基因
We have characterized a Rhizobium meliloti regulatory gene required for the expression of two closely linked symbiotic operons, the nitrogenase operon (nifHDK genes) and the “P2” operon. This regulatory gene maps to a 1.8 kb region located 5.5 kb upstream of the nif/fDK operon. The regulatory gene is required for the accumulation of MffDK and P2 mRNA and for the derepression of an R. meliloti nifH-/acZ fusion plasmid during symbiotic growth. The MH and P2 promoters can be activated in freeliving cultures of R. meliloti containing plasmids that produce the Escherichia coli nfrC (g/nG) or the Klebsiella pneumoniae nifA regulatory gene products constitutively. The R. meliloti regulatory gene hybridizes to E. coli nfrG (glnG) and, to a lesser extent, to K. pneumoniae nifA DNA. Our results suggest that the R. meliloti regulatory gene acts as a positive transcriptional activator and that it is related to the K. pneumoniae nif regulatory genes.