HPr prevents FruR-mediated facilitation of RNA polymerase binding to the fru promoter in Vibrio cholerae.
Chang-Kyu YoonSeung-Hwan LeeJing ZhangHye-Young LeeMin-Kyu KimYeong-Jae SeokPublished in: Nucleic acids research (2023)
Phosphorylation state-dependent interactions of the phosphoenolpyruvate (PEP):carbohydrate phosphotransferase system (PTS) components with transcription factors play a key role in carbon catabolite repression (CCR) by glucose in bacteria. Glucose inhibits the PTS-dependent transport of fructose and is preferred over fructose in Vibrio cholerae, but the mechanism is unknown. We have recently shown that, contrary to Escherichia coli, the fructose-dependent transcriptional regulator FruR acts as an activator of the fru operon in V. cholerae and binding of the FruR-fructose 1-phosphate (F1P) complex to an operator facilitates RNA polymerase (RNAP) binding to the fru promoter. Here we show that, in the presence of glucose, dephosphorylated HPr, a general PTS component, binds to FruR. Whereas HPr does not affect DNA-binding affinity of FruR, regardless of the presence of F1P, it prevents the FruR-F1P complex from facilitating the binding of RNAP to the fru promoter. Structural and biochemical analyses of the FruR-HPr complex identify key residues responsible for the V. cholerae-specific FruR-HPr interaction not observed in E. coli. Finally, we reveal how the dephosphorylated HPr interacts with FruR in V. cholerae, whereas the phosphorylated HPr binds to CcpA, which is a global regulator of CCR in Bacillus subtilis and shows structural similarity to FruR.
Keyphrases
- transcription factor
- dna binding
- escherichia coli
- dna methylation
- bacillus subtilis
- gene expression
- blood glucose
- dendritic cells
- type diabetes
- binding protein
- blood pressure
- metabolic syndrome
- regulatory t cells
- mouse model
- genome wide
- multidrug resistant
- biofilm formation
- heat stress
- oxidative stress
- insulin resistance
- pseudomonas aeruginosa
- heat shock
- skeletal muscle