苜蓿根瘤菌nod A蛋白在细胞中的定位

LOCALIZATION OF THE Nod A PROTEIN OF RHIZOBWM MELILOTI IN E. COLI

应用噬菌体T7 RNA聚合酶/启动子表达系统,质粒pT7—6作为载体,构建了带有首蓿根瘤菌(Rhizobium meliloti)nod A基因的重组质粒pBF3.nod A在T7启动子的控制下,经诱导在大肠杆菌JAKE中得到表达,产物为21.5kD多肽.对nod A基因在大肠杆菌中的翻译产物(NodA)进行细胞定位分析表明,NodA同时存在于细胞质和细胞膜中.

The translation product of the nod A of Rhizobium meliloti has been examined in T7 promoter plasmid vector and expressed in E.coli cells. Plasmid pBF3 carrying 1. 8kb BamHl-SacⅡ DNA fragment from pRM31 encodes 21. 5kD polypeptide(NodA). Localization studies of the nodA gene product in E. coli showed that the Nod A was present in both cytoplasm and membrane. Some NodA associates with interrior membrane of cells after translation in the cytoplasm.