Braun Martin, Silhavy Thomas J
Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
Mol Microbiol. 2002 Sep;45(5):1289-302. doi: 10.1046/j.1365-2958.2002.03091.x.
In Gram-negative bacteria, all components of the outer membrane are synthesized in the cytoplasm or the cytoplasmic leaflet of the inner membrane and must thus traverse the inner membrane and the periplasm on the way to their final destination. In this study, we show Imp/OstA to have characteristics typical for proteins involved in envelope biogenesis. Imp is essential and forms a high-molecular-weight disulphide-bonded complex in the outer membrane. Upon depletion of Imp, lipids and outer membrane proteins appear in a novel membrane fraction with higher density than the outer membrane. We propose Imp to be part of a targeting/usher system for components of the outer membrane.
在革兰氏阴性菌中，外膜的所有成分都在内质网或内膜的细胞质小叶中合成，因此在到达最终目的地的途中必须穿过内膜和周质。在本研究中，我们发现Imp/OstA具有参与包膜生物合成的蛋白质的典型特征。Imp是必不可少的，并且在外膜中形成高分子量的二硫键结合复合物。当Imp缺失时，脂质和外膜蛋白会出现在一个密度比外膜更高的新膜组分中。我们认为Imp是外膜成分靶向/输出系统的一部分。
