McNicholas P M, Chiang R C, Gunsalus R P
Department of Microbiology and Molecular Genetics, University of California at Los Angeles 90095-1489, USA.
FEMS Microbiol Lett. 1996 Nov 15;145(1):117-23. doi: 10.1016/0378-1097(96)00398-9.
The Escherichia coli modABCD operon, which encodes a high-affinity molybdate uptake system, is transcriptionally regulated in response to molybdate availability by ModE. Here we describe a highly effective enrichment protocol, applicable to any gene with a repressor role, and establish its application in the isolation of transposon mutations in modE. In addition we show that disruption of the ModE C-terminus abolishes derepression in the absence of molybdate, implying this region of ModE controls the repressor activity. Finally, a mutational analysis of a proposed molybdate binding motif indicates that this motif does not function in regulating the repressor activity of ModE.
大肠杆菌的modABCD操纵子编码一种高亲和力的钼酸盐摄取系统，它受ModE的调控，根据钼酸盐的可利用性进行转录调节。在此，我们描述了一种高效的富集方案，该方案适用于任何具有阻遏作用的基因，并确立了其在分离modE中转座子突变方面的应用。此外，我们还表明，在没有钼酸盐的情况下，ModE C端的破坏会消除去阻遏作用，这意味着ModE的这一区域控制着阻遏物活性。最后，对一个假定的钼酸盐结合基序的突变分析表明，该基序在调节ModE的阻遏物活性方面不起作用。
