Expression of ptsG encoding the major glucose transporter is regulated by ArcA in Escherichia coli.
Because the phosphoenolpyruvate:sugar phosphotransferase system plays multiple regulatory roles in addition to the phosphorylation-coupled transport of many sugars in bacteria, synthesis of its protein components is regulated in a highly sophisticated way. Thus far, the cAMP receptor protein (CRP) complex and Mlc are known to be the major regulators of ptsHIcrr and ptsG expression in response to the availability of carbon sources. In this report, we performed ligand fishing experiments by using the promoters of ptsHIcrr and ptsG as bait to find out new factors involved in the transcriptional regulation of the phosphoenolpyruvate:sugar phosphotransferase system in Escherichia coli, and we found that the anaerobic regulator ArcA specifically binds to the promoters. Deletion of the arcA gene caused about a 2-fold increase in the ptsG expression, and overexpression of ArcA significantly decreased glucose consumption. In vitro transcription assays showed that phospho-ArcA (ArcA-P) represses ptsG P1 transcription. DNase I footprinting experiments revealed that ArcA-P binds to three sites upstream of the ptsG P1 promoter, two of which overlap the CRP-binding sites, and the ArcA-P binding decreases the CRP binding that is essential for the ptsG P1 transcription. These results suggest that the response regulator ArcA regulates expression of enzyme IICB(Glc) mediating the first step of glucose metabolism in response to the redox conditions of growth in E. coli.
Jeong
Jin-Young
JY
Laboratory of Macromolecular Interactions, School of Biological Sciences and Institute of Microbiology, Seoul National University, Seoul 151-742, Korea.
Kim
You-Jin
YJ
Cho
Namwook
N
Shin
Dongwoo
D
Nam
Tae-Wook
TW
Ryu
Sangryeol
S
Seok
Yeong-Jae
YJ
D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D001692:Biological Transport; D000242:Cyclic AMP / Q000378:metabolism; D003850:Deoxyribonuclease I / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins; D017353:Gene Deletion; D005838:Genotype; D005947:Glucose / Q000378:metabolism*; D007763:Lac Operon; D008024:Ligands; D008969:Molecular Sequence Data; D009004:Monosaccharide Transport Proteins / Q000378:metabolism*; D010641:Phenotype; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000096:biosynthesis* / Q000737:chemistry; D010766:Phosphorylation; D010957:Plasmids / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012097:Repressor Proteins / Q000378:metabolism*; D014158:Transcription, Genetic; D001616:beta-Galactosidase / Q000378:metabolism
D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; D008024:Ligands; D009004:Monosaccharide Transport Proteins; D012097:Repressor Proteins; C041610:arcA protein, E coli; D000242:Cyclic AMP; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; C031629:phosphoenolpyruvate-glucose phosphotransferase; D003850:Deoxyribonuclease I; D001616:beta-Galactosidase; D005947:Glucose