Repressors
& Small Molecules
•Inducers can
inactivate repressors:
–IPTG
(Isopropylthio-ß-galactoside) à Lac
repressor
–aTc
(Anhydrotetracycline) à Tet repressor
•Use as a logical gate:
operator
promoter
gene
RNAP
active
repressor
operator
promoter
gene
RNAP
inactive
repressor
inducer
no
transcription
transcription
Inducer
Repressor
Output
