Membrane topology of the DrrB protein of the doxorubicin transporter of Streptomyces peucetius
Membrane topology of the DrrB protein of the doxorubicin transporter of Streptomyces peucetius
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DOI：
10.1074/jbc.m402898200
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发表时间：
2004-06-25
影响因子：
4.8
通讯作者：
Kaur, P
中科院分区：
文献类型：
--
作者：
Gandlur, SM;Wei, L;Kaur, P
柔红霉素和阿霉素是两种常用的抗癌药物，由土壤细菌粉红色链霉菌产生。编码DrrA和DrrB两种蛋白质的drrAB基因座决定了白链霉菌对这些抗生素的自身抗药性。DRRA是一种三磷酸腺苷结合蛋白。它属于ABC转运蛋白家族，与癌细胞的P-糖蛋白在序列和功能上有相似之处。DrrB是一种完整的膜蛋白，可能作为柔红霉素和阿霉素外流的转运蛋白。总而言之，DrrA和DrrB被认为形成了一个由ATP驱动的泵，用于这些药物的外流。已经克隆了drrAB基因，并在大肠杆菌中以功能形式表达了这两种蛋白。利用基因融合方法对DrrB蛋白进行了拓扑分析。创建了drrB基因与LacZ、PhoA或GFP报告基因的随机和定点融合。在融合数据的基础上，提出了DrrB蛋白的拓扑模型，该蛋白有8个跨膜结构域，N端和C端都在细胞质中。
Daunorubicin and doxorubicin, two commonly used anticancer agents, are produced by the soil bacterium Streptomyces peucetius. Self-resistance to these antibiotics in S. peucetius is conferred by the drrAB locus that codes for two proteins, DrrA and DrrB. DrrA is an ATP-binding protein. It belongs to the ABC family of transporters and shares sequence and functional similarities with P-glycoprotein of cancer cells. DrrB is an integral membrane protein that might function as a transporter for the efflux of daunorubicin and doxorubicin. Together, DrrA and DrrB are believed to form an ATP-driven pump for the efflux of these drugs. The drrAB locus has been cloned, and the two proteins have been expressed in a functional form in Escherichia coli. A topological analysis of the DrrB protein was performed using gene fusion methodology. Random and site-directed fusions of the drrB gene to lacZ, phoA, or gfp reporter genes were created. Based on the fusion data, a topological model of the DrrB protein is proposed in which the protein has eight membrane-spanning domains with both the N terminus and the C terminus in the cytoplasm.