MOLECULAR CHARACTERIZATION OF THE OLIGOPEPTIDE PERMEASE OF SALMONELLA-TYPHIMURIUM
MOLECULAR CHARACTERIZATION OF THE OLIGOPEPTIDE PERMEASE OF SALMONELLA-TYPHIMURIUM
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DOI：
10.1016/0022-2836(87)90332-9
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发表时间：
1987-05-05
影响因子：
5.6
通讯作者：
HIGGINS, CF
中科院分区：
文献类型：
--
作者：
HILES, ID;GALLAGHER, MP;HIGGINS, CF
鼠伤寒沙门氏菌的寡肽通透酶（Opp）是周质结合蛋白依赖性转运系统，并且处理含有2至5个氨基酸残基的任何肽。Opp起着重要的营养作用，也是细胞壁肽循环所必需的。我们已经确定了opp操纵子的核苷酸序列。除了先前通过遗传手段鉴定的四个opp基因（oppABCD）之外，第五个基因oppF被示出作为opp操纵子的一部分被共转录。使用反向遗传学，我们表明，oppF也编码的Opp运输系统的一个重要组成部分。这五种蛋白质OppABCDF是Opp功能所需的唯一蛋白质。研究了操纵子内opp表达和基因差异表达的调节。我们设计了一种简单的方法，构建lacZ基因融合到任何S。鼠伤寒沙门氏菌染色体基因，使用噬菌体Mu的衍生物。使用该程序，选择opp-lacZ基因融合体。所得Opp-LacZ杂合蛋白用于显示OppB、OppC和OppD是膜结合蛋白。详细比较的Opp组件与其他结合蛋白依赖的运输系统提供了深入了解这些运输系统的机制和演变。
The oligopeptide permease (Opp) of Salmonella typhimurium is a periplasmic binding protein-dependent transport system and handles any peptides containing from two to five amino acid residues. Opp plays an important nutritional role and is also required for the recycling of cell wall peptides. We have determined the nucleotide sequence of the opp operon. In addition to the four opp genes identified previously by genetic means (oppABCD) a fifth gene, oppF, is shown to be cotranscribed as part of the opp operon. Using reverse genetics, we show that oppF also encodes an essential component of the Opp transport system. The five proteins, OppABCDF, are shown to be the only proteins required for Opp function. Regulation of opp expression and of the differential expression of genes within the operon is investigated. We have devised a simple means of constructing lacZ gene fusions to any S. typhimurium chromosomal gene in vivo, using derivatives of bacteriophage Mu. Using this procedure, opp-lacZ gene fusions were selected. The resultant Opp-LacZ hybrid proteins were used to show that OppB, OppC and OppD are membrane-associated proteins. A detailed comparison of the Opp components with those of other binding protein-dependent transport systems provides insight into the mechanism and evolution of these transport systems.