PEPTIDOGLYCAN-ASSOCIATED LIPOPROTEIN-TOLB INTERACTION
PEPTIDOGLYCAN-ASSOCIATED LIPOPROTEIN-TOLB INTERACTION
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DOI：
10.1074/jbc.270.19.11071
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发表时间：
1995-05-12
影响因子：
4.8
通讯作者：
BENEDETTI, H
中科院分区：
文献类型：
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作者：
BOUVERET, E;DEROUICHE, R;BENEDETTI, H
托拉、B、-Q和-R蛋白参与维持大肠杆菌的细胞被膜完整性;它们被A组大肠杆菌素和一些丝状噬菌体的单链DNA寄生，以允许它们进入细胞，托拉和TolR通过单个跨膜结构域锚定到内膜上，TolQ是具有三个跨膜片段的完整膜蛋白，最近发现TolB是周质的，尽管它是部分膜结合的。后一结果表明TolB可能与膜蛋白相互作用。其他证据支持TolB复合物的存在。为了进一步表征这种复合物，我们研究了哪些蛋白与TolB相互作用。为此，使用了两种不同的方法，首先，我们利用标记的TolB（TolBep）的存在在天然条件下进行免疫沉淀，以保持TolBep与其它蛋白质的推定结合。其次，进行了与甲醛的体内交联实验。这两种方法导致了相同的结果，并首次证明了Tol系统的组分TolB，与位于外膜的蛋白质，肽聚糖相关脂蛋白相互作用。
TolA, B, -Q, and -R proteins are involved in maintaining the cell envelope integrity of Escherichia coli; they have been parasitized by the group A colicins and the single strand DNA of some filamentous bacteriophages to permit them to enter the cells, TolA and TolR are anchored to the inner membrane by a single transmembrane domain, TolQ is an integral membrane protein with three transmembrane segments, and TolB has re cently been found to be periplasmic although it is partially membrane-associated The latter result suggests that TolB might interact with membrane proteins, Other lines of evidence favor the existence of a Tol complex, To further characterize this complex, we investigated which proteins interact with TolB, For this purpose, two different methods were used, First, we took advantage of the existence of a tagged TolB (TolBep) to perform immunoprecipitation under native conditions in order to preserve the putative associations of TolBep with other proteins, Secondly, in vivo cross-linking experiments with formaldehyde were performed, These two approaches led to the same result and demonstrated for the first time that a component of the Tol system, TolB, interacts with a protein located in the outer membrane, the peptidoglycan-associated lipoprotein.