Part:BBa_K1682000

Wild Type P_kdpF - potassium responsive promoter

Biology of P_kdpF

The potassium ion uptake in E. coli is regulated by several systems under different conditions. The potassium ion transporters, Trk and Kup are constitutively expressed (Epstein & Kim, 1971) while KdpFABC, another transporter is activated under low [K+] conditions (Laimins et al., 1981).

The kdpFABC operon is controlled by the KdpDE two-component system (TCS) which consists of KdpD, a membrane-bound sensor kinase, and KdpE, a cytoplasmic response regulator (Polarek, 1992; Walderhaug, 1992). KdpD is stimulated by both intracellular and extracellular K+ (Jung, 2000; Jung, 2001; Roe, 2000; Yan, 2011a; Laermann, 2013). KdpD phosphorylates KdpE upon low potassium concentration (Voelkner, 1993; Puppe, 1996; Jung, 1997a; Jung, 2000). Under an increase in [K+], KdpD phosphatase activity will be enhanced, causing a decrease in phospho-KdpE and kdpFABC expression. Phosphorylated KdpE turns on the expression of kdpFABC (Zhang, 2014a; Laermann, 2013).

Construct for characterization

To make a potassium-sensing device, we obtained the promoter, PkdpF, and combined it with a GFP reporter, BBa_E0240, in BioBrick RFC10 standard so that the promoter activity in different potassium level can be detected and characterized.

Sequence and Features

Assembly Compatibility:

• 10
  INCOMPATIBLE WITH RFC[10]

  Illegal EcoRI site found at 61
  
• 12
  INCOMPATIBLE WITH RFC[12]

  Illegal EcoRI site found at 61
  
• 21
  INCOMPATIBLE WITH RFC[21]

  Illegal EcoRI site found at 61
  
• 23
  INCOMPATIBLE WITH RFC[23]

  Illegal EcoRI site found at 61
  
• 25
  INCOMPATIBLE WITH RFC[25]

  Illegal EcoRI site found at 61
  
• 1000
  COMPATIBLE WITH RFC[1000]