Dual transcriptional regulation of the Escherichia coli phosphate-starvation-inducible psiE gene of the phosphate regulon by PhoB and the cyclic AMP (cAMP)-cAMP receptor protein complex
Sk. Kim et al., Dual transcriptional regulation of the Escherichia coli phosphate-starvation-inducible psiE gene of the phosphate regulon by PhoB and the cyclic AMP (cAMP)-cAMP receptor protein complex, J BACT, 182(19), 2000, pp. 5596-5599
We have shown that the Escherichia coli phosphate-starvation-inducible psiE
gene is regulated by both phosphate and the carbon source by using both la
cZ and chloramphenicol acetyltransferase gene (cat) fusions. Yet, under all
conditions tested, a single transcriptional start site lying 7 bp downstre
am of a predicted -10 region was revealed by primer extension analysis, DNa
se I footprinting showed that the PhoB transcriptional-activator protein pr
otects two predicted pho buses lying upstream of and near the -35 promoter
region. Similar analysis showed that the cyclic AMP (cAMP)-cAMP receptor pr
otein (cAMP-CRP) complex binds a region that overlaps with the downstream p
ho box. These results, together with measurements of the in vivo psiE promo
ter activity under various conditions, show that expression of the psiE gen
e is under direct positive and negative control by PhoB and cAMP CRP, respe
ctively.