Evidence that nitrogen regulatory gene ntrC of Salmonella typhimurium is transcribed from the glnA promoter as well as from a separate ntr promoter.
Evidence that nitrogen regulatory gene ntrC of Salmonella typhimurium is transcribed from the glnA promoter as well as from a separate ntr promoter.
复制标题
有证据表明鼠伤寒沙门氏菌的氮调节基因ntrC是从glnA启动子以及单独的ntr启动子转录的。
DOI：
10.1007/bf00327426
复制
发表时间：
1984
期刊：
影响因子：
--
通讯作者：
Kustu,S
中科院分区：
文献类型：
--
作者：
Krajewska-Grynkiewicz,K;Kustu,S
Previous work has indicated that nitrogen regulatory genesntrBandntrCofSalmonella typhimuriumare closely linked toglnA, the structural gene encoding glutamine synthetase; proceeding clockwise the order of genes in the 86 U region of the map ispolA...ntrC ntrB glnA glnApromoter...rha. To studyntrCtranscription we have constructed operon fusions ofntrCtolacZusing the Casadaban Mud1 (Aprlac) phage so that we can measure β-galactosidase activity as a reflection ofntrCtranscription and we have introduced into fusion strains promoter constitutive mutations atglnA[glnAp(Con)]. TheglnAp(Con) mutations, which elevateglnAexpression in fusion strains, also elevate β-galactosidase activity, indicating thatntrCis cotranscribed withglnA. Consistent with this interpretation, polar insertion mutations inglnAdecrease β-galactosidase activity of fusion strains carryingglnAp(Con) mutations. However,glnAinsertions do not eliminate β-galactosidase activity ofglnAp(Con)ntrC::Mud1 strains and they have little effect on β-galactosidase activity of the originalntrC::Mud1 fusion strains. The latter results confirm thatntrCcan also be transcribed from anntrpromoter downstream ofglnA. Polar insertion mutations inntrBeliminate β-galactosidase activity of both the original fusion strains and fusion strains carryingglnA(Con) mutations, indicating that thentrpromoter lies betweenglnAandntrB.
