Genetic analysis of the stationary phase-induced mcb operon promoter in Escherichia coli.
Genetic analysis of the stationary phase-induced mcb operon promoter in Escherichia coli.
复制标题
大肠杆菌稳定期诱导的 mcb 操纵子启动子的遗传分析。
DOI：
10.1046/j.1365-2958.1998.00690.x
复制
发表时间：
1998
影响因子：
3.6
通讯作者：
Siegele,DA
中科院分区：
文献类型：
--
作者：
Mao,W;Siegele,DA
A combination of deletion analysis and random mutagenesis was used to identify regulatory elements in Pmcb, the stationary phase‐induced promoter of themcboperon. Our results indicate that Pmcbis controlled by at least three different factors, two previously identified and at least one unknown factor, which act at four different sites in the promoter. Sequences between −344 and −164 upstream of the transcriptional start site were required for wild‐type levels ofmcbtranscription in stationary phase. More dramatic reductions in both exponential and stationary phase expression were observed when sequences from −164 to −54 were deleted. Point mutations located between −105 and −138 decreased both exponential and stationary phase expression. All but one of these mutations decreased OmpR‐dependent activation of Pmcbtranscription. EmrR, also known as MprA, acts directly or indirectly at sequences downstream of −54 to repress Pmcb. A minimal promoter containing sequences from −34 to +79 was still induced ≥10‐fold in stationary phase. Point mutations within this region identified sequences at −8, −11, −30, −31 and −32 as important for Pmcbactivity. These bases are in the gearbox sequence, present in Pmcband several other stationary phase‐inducedEscherichia colipromoters.
