Abstract
Synthetic biological systems often require multiple, independently inducible promoters in order to control the expression levels of several genes; however, cross talk between the promoters limits this ability. Here, we demonstrate the directed evolution of AraC to construct an arabinose-inducible (P(BAD)) system that is more compatible with IPTG (isopropyl-beta-D-1-thiogalactopyranoside) induction of a lactose-inducible (P(lac)) system. The constructed system is 10 times more sensitive to arabinose and tolerates IPTG significantly better than the wild type. Detailed studies indicate that the AraC dimerization domain and C terminus are important for the increased sensitivity of AraC to arabinose.
Publication types
-
Research Support, N.I.H., Extramural
MeSH terms
-
AraC Transcription Factor / drug effects*
-
AraC Transcription Factor / genetics
-
Arabinose / metabolism
-
Arabinose / pharmacology*
-
Escherichia coli / genetics*
-
Escherichia coli / growth & development
-
Escherichia coli / metabolism
-
Escherichia coli Proteins / drug effects*
-
Escherichia coli Proteins / genetics
-
Evolution, Molecular
-
Isopropyl Thiogalactoside / metabolism
-
Isopropyl Thiogalactoside / pharmacology*
-
Lactose / pharmacology*
-
Mutagenesis, Site-Directed
-
Operon
-
Promoter Regions, Genetic / drug effects*
-
Promoter Regions, Genetic / physiology
Substances
-
AraC Transcription Factor
-
AraC protein, E coli
-
Escherichia coli Proteins
-
Isopropyl Thiogalactoside
-
Arabinose
-
Lactose