Nucleotide sequence of traQ and adjacent loci in the Escherichia coli K-12 F-plasmid transfer operon.
Nucleotide sequence of traQ and adjacent loci in the Escherichia coli K-12 F-plasmid transfer operon.
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大肠杆菌 K-12 F 质粒转移操纵子中 traQ 和相邻基因座的核苷酸序列。
DOI：
10.1128/jb.171.1.213-221.1989
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发表时间：
1989
影响因子：
3.2
通讯作者：
Ippen-Ihler,K
中科院分区：
文献类型：
--
作者：
Wu,JH;Ippen-Ihler,K
分析包括基因trbA、traQ和trbB的F tra操纵子区域。DNA序列的测定表明，在tra操纵子链上，trbA基因开始于traF远端的19个核苷酸（nt），编码115个氨基酸的蛋白质，Mr-12，946。traQ基因起始于trbA远端399 nt处，编码94个氨基酸的Mr-10，867蛋白。发现编码179个氨基酸的Mr-19，507蛋白的trbB基因与traQ略微重叠;其起始密码子在traQ终止密码子之前11 nt开始。这些基因表达的产物的蛋白质分析和亚细胞分级分离表明，trbB产物被加工，并且这种蛋白质的成熟形式在周质中积累。相比之下，trbA和traQ的蛋白产物似乎是未加工的膜相关蛋白。DNA序列还揭示了在trbA和traQ之间的区域中存在先前未被怀疑的基因座阿尔塔。发现阿尔塔开放阅读框架位于与F tra操纵子互补的DNA链上，可编码104个氨基酸，12，132-道尔顿的多肽。由于该序列不会作为tra操纵子的一部分表达，因此在galK融合载体系统中评估潜在阿尔塔启动子区的活性。还通过测试artA-β-半乳糖苷酶融合蛋白的表达来检查阿尔塔启动子和翻译起始位点的体内利用。这些结果表明阿尔塔基因从其自身的启动子表达。
The F tra operon region that includes genes trbA, traQ, and trbB was analyzed. Determination of the DNA sequence showed that on the tra operon strand, the trbA gene begins 19 nucleotides (nt) distal to traF and encodes a 115-amino-acid, Mr-12,946 protein. The traQ gene begins 399 nt distal to trbA and encodes a 94-amino-acid, Mr-10,867 protein. The trbB gene, which encodes a 179-amino-acid, Mr-19,507 protein, was found to overlap slightly with traQ; its start codon begins 11 nt before the traQ stop codon. Protein analysis and subcellular fractionation of the products expressed by these genes indicated that the trbB product was processed and that the mature form of this protein accumulated in the periplasm. In contrast, the protein products of trbA and traQ appeared to be unprocessed, membrane-associated proteins. The DNA sequence also revealed the presence of a previously unsuspected locus, artA, in the region between trbA and traQ. The artA open reading frame was found to lie on the DNA strand complementary to that of the F tra operon and could encode a 104-amino-acid, 12,132-dalton polypeptide. Since this sequence would not be expressed as part of the tra operon, the activity of a potential artA promoter region was assessed in a galK fusion vector system. In vivo utilization of the artA promoter and translational start sites was also examined by testing expression of an artA-beta-galactosidase fusion protein. These results indicated that the artA gene is expressed from its own promoter.