摘要
细菌响应营养饥饿或环境胁迫的反应称为严谨反应.本文采用Native-PAGE技术从毒死蜱胁迫下的Klebsiella sp.CPK菌株全细胞蛋白中分离得到了1种特异蛋白,该蛋白通过TOF-MS测序推测为魔斑合成酶RelA.对该蛋白编码基因进行PCR扩增,并利用ORF Finder,showorf等生物信息学软件对其开放性阅读框架进行鉴定,获得了1个全长为2 238bp的完整relA基因.序列及系统发育分析表明,Klebsiella sp. CPK菌株的RelA蛋白与E.coli RelA蛋白的同源性为92%,但与双功能的Rel-SpoT蛋白同源性却比较低.由此推测,Klebsiella sp. CPK RelA蛋白可能只有魔斑合成酶活性.另外,对relA基因进行功能互补分析表明,该基因编码的特异蛋白具有魔斑合成酶活性,从而证明了Klebsiella sp. CPK菌株在毒死蜱胁迫下能够产生典型的严谨反应。
Bacteria respond to nutritional starvation or environmental stress through the stringent response.In this study,a specific protein was obtained through whole cell protein native-PAGE,which was from a chlorpyrifos degrader Klebsiella sp.CPK treated by chlorpyrifos in the nutrient rich medium TYC.The specific protein was identified as a（p） ppGpp synthetase（RelA） through TOF-MS sequencing.A 2 238 bp complete（p）ppGpp synthetase coding region was cloned and identified by ORF Finder（NCBI）,showorf（EMBOSS explorer） bioinformatics software etc.Sequence and phylogenetic analysis of Klebsiella sp.CPK RelA showed that it shared 92% identity to E.coli RelA,but it showed low identity to bifunctional Rel-SpoT protein.These results indicated that Klebsiella sp.CPK RelA may only have（p）ppGpp synthetase activity.In addition,complementation test of Klebsiella sp.CPK relA in E.coli proved that the RelA has only（p）ppGpp synthetase activity.This study showed that chlorpyrifos stress could mount a classic stringent response in Klebsiella sp.CPK
出处
《中国生物化学与分子生物学报》
CAS
CSCD
北大核心
2010年第12期1128-1134,共7页
Chinese Journal of Biochemistry and Molecular Biology
基金
国家高科技研究发展计划(863计划
No.2008AA10Z402
No.2006AA10Z401)
中国农业科学院基础研究基金(No.0042009001)~~
