A NOVEL PERIPLASMIC CARRIER PROTEIN INVOLVED IN THE SORTING AND TRANSPORT OF ESCHERICHIA-COLI LIPOPROTEINS DESTINED FOR THE OUTER-MEMBRANE
A NOVEL PERIPLASMIC CARRIER PROTEIN INVOLVED IN THE SORTING AND TRANSPORT OF ESCHERICHIA-COLI LIPOPROTEINS DESTINED FOR THE OUTER-MEMBRANE
复制标题
DOI：
10.1002/j.1460-2075.1995.tb07342.x
复制
发表时间：
1995-07-17
期刊：
影响因子：
11.4
通讯作者：
TOKUDA, H
中科院分区：
文献类型：
--
作者：
MATSUYAMA, S;TAJIMA, T;TOKUDA, H
脂蛋白位于大肠杆菌的外膜或内膜中，具体取决于位于 N 末端脂肪酰化 Cys 旁边的氨基酸种类。然而，在原生质体中表达的主要外膜脂蛋白（Lpp）作为成熟形式保留在内膜中。在周质中发现了一种对于Lpp从内膜释放所必需的新蛋白质并进行了纯化。确定了该20kDa蛋白质（p20）的部分氨基酸序列并用于克隆p20基因。基因测序显示p20是作为带有信号序列的前体合成的，p20仅与外膜定向脂蛋白如Lpp形成可溶性复合物，表明p20在脂蛋白的分选中起着关键作用。在 p20 存在的情况下，从内膜释放的 Lpp 在体外被特异性组装到外膜中。这些结果表明p20是一种周质载体蛋白，参与脂蛋白从内膜到外膜的易位。
Lipoproteins are localized in the outer or inner membrane of Escherichia coli, depending on the species of amino acid located next to the N-terminal fatty acylated Cys. The major Outer membrane lipoprotein (Lpp) expressed in spheroplasts was, however, retained in the inner membrane as a mature form, A novel protein that is essential for the release of Lpp from the inner membrane was discovered in the periplasm and purified, The partial amino acid sequence of this 20 kDa protein (p20) was determined and used to clone a gene for p20. Sequencing of the gene revealed that p20 is synthesized as a precursor with a signal sequence, p20 formed a soluble complex only with outer membrane-directed lipoproteins such as Lpp, indicating that p20 plays a critical role in the sorting of lipoproteins. Lpp released from the inner membrane in the presence of p20 was specifically assembled into the outer membrane in vitro. These results indicate that p20 is a periplasmic carrier protein involved in the translocation of lipoproteins from the inner to the outer membrane.