GENETIC AND MOLECULAR CHARACTERIZATION OF THE ESCHERICHIA-COLI SECD OPERON AND ITS PRODUCTS
GENETIC AND MOLECULAR CHARACTERIZATION OF THE ESCHERICHIA-COLI SECD OPERON AND ITS PRODUCTS
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DOI：
10.1128/jb.176.3.804-814.1994
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发表时间：
1994-02-01
影响因子：
3.2
通讯作者：
BECKWITH, J
中科院分区：
文献类型：
--
作者：
POGLIANO, KJ;BECKWITH, J
大肠杆菌的secD操纵子是蛋白质有效输出所必需的。我们的特点是这个操纵子，并发现，除了secD和secF，它包含上游基因yajC，但不是基因queA或tgt，在以前的报告相反。对体外构建并重组到染色体上的yajC突变的分析表明，yajC既不是必需的，也不是sec基因。secD操纵子不响应于分泌缺陷或温度变化而被诱导。TnphoA融合已被用于分析SecD在内膜中的拓扑结构;该蛋白质包含六个跨膜段和一个大的周质结构域。TnphoA与SecD和SecF的融合体也已重组到染色体上，并用于测定细胞内这些蛋白质的水平。我们的研究结果表明，每个细胞中的SecD和SecF分子少于30个。
The secD operon of Escherichia coli is required for the efficient export of proteins. We have characterized this operon, and found that, in addition to secD and secF, it contains the upstream gene yajC, but not the genes queA or tgt, in contrast to previous reports. An analysis of yajC mutations constructed in vitro and recombined onto the chromosome indicates that yajC is neither essential nor a sec gene. The secD operon is not induced in response to either secretion defects or temperature changes. TnphoA fusions have been used to analyze the topology of SecD in the inner membrane; the protein contains six transmembrane stretches and a large periplasmic domain. TnphoA fusions to SecD and SecF have also been recombined onto the chromosome and used to determine the level of these proteins within the cell. Our results indicate that there are fewer than 30 SecD and SecF molecules per cell.