Part:BBa_K559011

Pgad - Intracellular Chloride-Sensing Cassette

Pgad is chloride-sensitive promoter which was first discovered in Lactococcus lactis1, which is a gram-positive bacterium which can live in acidic environment. In this operon, gadC is glutamate-gamma-aminobutyrate antiporter and gadB is glutamate decarboxylase. They are both involved in intracellular pH regulation and co-expressed in the same operon under the control of Pgad. The gene before Pgad, named gadR, which is constitutively expressed under the control of PgadR, is a positive regulator of Pgad coupled genes while intracellular chloride is level elevated.

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  COMPATIBLE WITH RFC[21]
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  COMPATIBLE WITH RFC[1000]

Usage and Biology

It has been used to fuse with GFP BBa_E0040 to quantitatively control GFP gene expression by providing different chloride concentration. The results can be seen in Part:BBa_K559011:Experience.

Also, it has been cooperated with BBa_K559010 halorhodopsin complete system for the photo-tunable gene expression platform. BBa_K559010 co-related between light and intracellular chloride ion, with this Pgad takes chloride ions as the intermediate to fine-control gene expression level.