Abstract:

Two plastid division genes, NtFtsZ1 and NtFtsZ2 isolated from Nicotiana tabacum L. were fused with gfp and expressed in Escherichia coli. The regular localizations of full length NtFtsZs∶GFP along the filamentous bacteria indicated that the NtFtsZs could recognize the potential division sites in E. coli and be polymerized with heterogeneous FtsZ from bacteria. The overexpression of NtFtsZs∶gfp inhibited the division of host strain cells and resulted in the long filamentous bacterial morphology. These results suggested that eukaryotic ftsZs have similar function to their prokaryotic homologs. Meanwhile, the different deletions of motifs of NtFtsZs are also employed to investigate the functions of these proteins in E. coli. The results showed that the C terminal domains of NtFtsZs were related to the correct localization of NtFtsZs in E. coli and the N terminal domains of NtFtsZs were responsible for the polymerization of homogeneous and heterogeneous FtsZ proteins. The significance of these results in understanding the functions of NtFtsZs in plastid division were discussed.

烟草质体分裂蛋白NtFtsZs, 在大肠杆菌中的定位分析
王 东₁ 孔冬冬₁ 鞠传丽₂ 胡 勇₂ 何奕昆_1,2  孙敬三_1*

（1. 中国科学院植物研究所，北京100093；2. 首都师范大学生物系，北京100037）

摘要：分别构建了两个烟草(Nicotiana tabacum L.)质体分裂基因NtFtsZ1和NtFtsZ2与编码绿色荧光蛋白的gfpS65A、V68L、S72A基因相融合的原核表达载体,并导入大肠杆菌( Escherichia coli ) JM109菌株中进行表达.全长NtFtsZs∶GFP融合蛋白在菌体中有规律地定位,暗示NtFtsZs能识别大肠杆菌潜在的分裂位点,并能与大肠杆菌的内源FtsZ发生聚合作用;融合蛋白的诱导表达抑制了宿主菌的分裂,形成了明显的丝状菌体,证明真核生物的 ftsZ 基因与大肠杆菌的 ftsZ 基因有相似的作用.同时构建了NtFtsZs不同缺失的原核表达载体,对这两个基因所编码蛋白不同结构域的功能做了初步分析.实验结果表明,烟草FtsZ蛋白的C端结构域与其在大肠杆菌细胞中的正确定位有关.

关键词： 烟草；质体分裂基因；NtFtsZ；绿色荧光蛋白；缺失表达；原核定位

通讯作者。E-mail:yhe @ duke.edu;sunjs @ ns.ibcas.ac.cn

Key words: Nicotiana tabacum, plastid division gene, NtFtsZ, GFP, localization in Escherichia coli