枯草杆菌强基因启动子DNA片段的序列分析

SEQUENCE ANALYSIS OF DNA FRAGMENTS CONTAINING STRONG PROMOTER ACTIVITY FROM Bacillus subtilis AS1.398

对利用基因启动子探针型载体ｐＳＵＰＶ２，从枯草杆菌ＡＳ１．３９８中克隆３个稳定的具有强启动功能的ＤＮＡ片段，进行限制酶切分析发现，ｐＢＳＵ２２和ｐＢＳＵ４３中的插入片段小于０．２ｋｂ，ｐＢＳＵ４４中的插入片段为３ｋｂ．测序结果表明，３个插入片段中都有较为典型的原核生物基因启动子序列，其中ｐＢＳＵ２２和ｐＢＳＵ４３的插入序列几乎完全相同．同源性分析结果表明，这３个基因启动子序列与枯草杆菌全基因组序列中的两个未知功能的基因启动子序列，其同源性高达７０％以上．

Many DNA fragments containing promoter activity had been previously cloned from Bacillus subtilis AS1.398 by using promoter probe plasmid vector pSUPV2.Severn of them,which showed much higher promoter activity,were chosen for further study.By using kanamycin resistance test,three recombinants named pBSU22,pBSU43 and pBSU44 displayed the highest promoter activity.Restriction map analysis of these three plasmids demonstrated that the insert fragment in pBSU22 and pBSU43 was shorter than 0.2kb,and the one in pBSU44 was about 3kb.Therefore,the whole inserted fragment of pBSU22 and pBSU43 and 3’ terminal segment of the insert of pBSU44 were sequenced.The sequence analysis showed that they all had some typical prokaryotic promoter characters and the inserts in both pBSU22 and pBSU43 had almost the identical sequences.Results from homologous comparison through Internet demonstrated that they had high similarity with promoter sequences of some genes whose function have been unknown in the genome of Bacillus subtilis in the Genebank.