chlC (nar) operon of Escherichia coli includes structural genes for alpha and beta subunits of nitrate reductase.
chlC (nar) operon of Escherichia coli includes structural genes for alpha and beta subunits of nitrate reductase.
复制标题
大肠杆菌的 chlC (nar) 操纵子包括硝酸还原酶的 α 和 β 亚基的结构基因。
DOI：
10.1128/jb.153.3.1513-1520.1983
复制
发表时间：
1983
影响因子：
3.2
通讯作者：
DeMoss,JA
中科院分区：
文献类型：
--
作者：
Edwards,ES;Rondeau,SS;DeMoss,JA
硝酸还原酶的α和β亚基的合成由20 chlC：：Tn 5插入突变体的大肠杆菌测定免疫沉淀的亚基从细胞提取物的馏分。只有两个突变体以可检测的量产生任一亚基;这两个积累了α亚基，但没有β亚基。在这两种情况下，α亚基存在于胞质组分中，与野生型细胞相反，其中两个亚基主要存在于膜组分中。将含有来自五个突变体的Tn 5插入片段的EcoRI限制性片段克隆到pBR 322中。插入定位在两个连续的EcoRI片段上，跨越与两个片段的连续末端重叠的5.6千碱基区域。允许α亚基形成的插入定义了5.6-脱氢酶区域的一端。结果表明，编码硝酸还原酶α和β亚基的基因是chlC（nar）操纵子的一部分，该操纵子以α导致β的方向转录。
The synthesis of the alpha and beta subunits of nitrate reductase by 20 chlC::Tn5 insertion mutants of Escherichia coli was determined by immune precipitation of the subunits from fractions of cell extracts. Only two of the mutants produced either subunit in detectable amounts; these two accumulated the alpha subunit, but no beta subunit. In both cases the alpha subunit was present in the cytosolic fraction, in contrast to wild-type cells, in which both subunits are present mainly in the membrane fraction. EcoRI restriction fragments containing the Tn5 inserts from five of the mutants were cloned into pBR322. The insertions were localized on two contiguous EcoRI fragments spanning a 5.6-kilobase region that overlapped the contiguous ends of the two fragments. An insertion that permitted alpha subunit formation defined one end of the 5.6-kilobase region. The results indicated that the genes encoding the alpha and beta subunits of nitrate reductase were part of a chlC (nar) operon that is transcribed in the direction alpha leads to beta.