嗜麦芽菌素P28尾鞘基因启动子活性分析  

Activity Analysis for Sheath Tail Gene Promoter of Maltocin P28

作　　者：于志洋 黄玉屏[1] YU Zhiyang;HUANG Yuping(College of Life Sciences,Wuhan University,Wuhan 430072,Hubei,China)

机构地区：[1]武汉大学生命科学学院

出　　处：《武汉大学学报（理学版）》2018年第4期343-348,共6页Journal of Wuhan University:Natural Science Edition

基　　金：湖北省自然科学基金(2014CFB699);国家微生物资源平台项目(NIMR-2017-8)资助

摘　　要：嗜麦芽菌素P28是由嗜麦芽寡养单胞菌（Stenotrophomonas maltophilia）合成的细菌素,启动子Ps控制其主要结构基因（尾鞘基因和尾管基因）的转录.本研究首先用RACE方法确定嗜麦芽菌素P28的主要结构基因转录起始位点位于尾鞘基因翻译起始位点ATG上游47bp处的G碱基,然后以lacZ（β-半乳糖苷酶基因）为报告基因对201bp长的启动子Ps从5′端进行缺失突变,发现具有启动活性的最小启动子片段长度为55bp.当启动子片段截短为89bp时,启动子Ps-89活性不仅有明显升高,同时不受丝裂霉素C影响.扫描突变分析Ps-201启动子中124bp与89bp之间的碱基,结果显示,碱基序列-GTCTG-是Ps-201的关键调控序列,突变后活性提高了2.53倍.Maltocin P28 is a kind of bacteriocin produced by Stenotrophomonas maltophilia.Its two main structural genes,the tail sheath gene and tube gene,are transcribed in one operon.The promoter Psupstream of the tail sheath gene controls their transcription.Using the RACE＇s method,the transcription initiation site of the tail sheath gene was confirmed at Guanosine（G）,which was 47 bp upstream the translation initiation codon ATG.In this study,lacZ（β-galactosidase）was chosen as a reporter gene to analyze the promoter activity.The length of promoter Ps-201 was gradually deleted from 5′-terminal and then serial deletion mutants were constructed.Theβ-galactosidase activities of recombinant strains show that the shortest length of Psis 55 bp.The promoter activity has a significant increase and is not affected by mitomycin C when the promoter length is shortened to 89 bp.Subsequently,the scanning mutation of nucleotides between 124 bp and 89 bp in Ps-201 indicates that the nucleotide-GTCTG-is the key regulatory sequence of Ps-201,as the activity of the mutant increases 2.53 folds.

关 键 词：嗜麦芽寡养单胞菌 嗜麦芽菌素 启动子 调控序列 

分 类 号：Q93[生物学—微生物学]