【摘要】 用含Tn5转座子的质粒pRL10 6 3a诱变苜蓿中华根瘤菌 (Sinorhizobiummeliloti) 0 4 2BM ,得到盐敏感突变株0 4 2BML 2。采用转座子挽救法对Tn5插入位点两边的序列进行克隆与测序 ,获得了 1179bp的转座子插入位点侧翼DNA序列。在GenBank中进行序列同源性和基因定位分析 ,结果表明 :转座子插入在一个功能未知的基因内部 ,此基因长 6 2 70bp。研究证明 :该基因与 0 4 2BM的耐盐性有关 ,并定名为rtsC。氨基酸疏水性分析表明 ,在RtsC蛋白的N端有两个跨膜区 ,该蛋白与细菌趋化性相关蛋白的功能域有同源性。并对RtsC蛋白在苜蓿中华根瘤菌0 4 2BM耐盐性中的作用进行了讨论更多还原

【Abstract】 Salt sensitive mutant 042BML-2 was obtained by mutating Sinorhizobium meliloti 042BM with transposon Tn5 carried on the plasmid pRL1063a.By transposon rescue,a 1.179 kb of DNA sequence of S.meliloti flanking the Tn5 insertion site was obtained.The sequence similarity analysis through BLAST analysis in GenBank revealed the transposon was inserted into a functionally unknown gene,which is 6 270 bp in length,of S.meliloti,and the gene was named rtsC.This study indicated that rtsC was associated with salt tolerance in S.meliloti 042BM.Hydrophobicity profile analysis of the putative amino acid sequence showed that two predicted transmembrane domains existed in N-terminal portion of RtsC.The significance of RtsC protein in the salt-tolerance in S.meliloti was discussed.更多还原