Roof S K, Allard J D, Bertrand K P, Postle K
Department of Microbiology, Washington State University, Pullman 99164-4233.
J Bacteriol. 1991 Sep;173(17):5554-7. doi: 10.1128/jb.173.17.5554-5557.1991.
Alkaline phosphatase (PhoA) fusions to TonB amino acids 32, 60, 125, 207, and 239 (the carboxy terminus) all showed high PhoA activity; a PhoA fusion to TonB amino acid 12 was inactive. The full-length TonB-PhoA fusion protein was associated with the cytoplasmic membrane and retained partial TonB function. These results support a model in which TonB is anchored in the cytoplasmic membrane by its hydrophobic amino terminus, with the remainder of the protein, including its hydrophobic carboxy terminus, extending into the periplasm.
碱性磷酸酶（PhoA）与托敏B（TonB）的第32、60、125、207和239位氨基酸（羧基末端）融合均显示出高PhoA活性；PhoA与托敏B第12位氨基酸的融合无活性。全长托敏B - PhoA融合蛋白与细胞质膜相关，并保留了部分托敏B功能。这些结果支持了一种模型，即托敏B通过其疏水氨基末端锚定在细胞质膜中，蛋白质的其余部分，包括其疏水羧基末端，延伸到周质中。
