title: Natural LacI from E. coli yields faster response and higher level of expression than the LVA-tagged LacI.
abstract: The lac promoter is one of the most commonly used promoters for expression control of recombinant genes in E. coli. In the absence of galactosides, the lac promoter is repressed by its repressor protein LacI. Since the lac promoter is regulated by a repressor, overexpression of LacI is necessary for regulation when the promoter is introduced on a high-copy plasmid. For that purpose, a modified variant of LacI, a LVA-tagged LacI, was submitted to the Registry of Standard Biological Parts and has been used for more than 500 constructs since then. We have found, however, that natural LacI is superior to the LVA-tagged LacI as controller of expression.
authors.affiliation: Department of Biochemistry and Molecular Biology, ‡Department of Cancer & Inflammation Research, §Department of Mathematics and Computer Science, ∥SDU Business, University of Southern Denmark , Campusvej 55, 5230 Odense M, Denmark.
authors.forename: Patrick Rosendahl
authors.initials: PR
authors.lastname: Andreassen
authors.forename: Sofie
authors.initials: S
authors.lastname: Fredberg
authors.forename: Mattias
authors.initials: M
authors.lastname: Horan
authors.forename: Maria Højberg
authors.initials: MH
authors.lastname: Knudsen
authors.forename: Kirstine
authors.initials: K
authors.lastname: Jacobsen
authors.forename: Andreas
authors.initials: A
authors.lastname: Kjær
authors.forename: Thøger Jensen
authors.initials: TJ
authors.lastname: Krogh
authors.forename: Tina
authors.initials: T
authors.lastname: Kronborg
authors.forename: Nicky Cordua
authors.initials: NC
authors.lastname: Mattsson
authors.forename: Sissel Ida
authors.initials: SI
authors.lastname: Schmidt
authors.forename: Heidi
authors.initials: H
authors.lastname: Wille
authors.forename: Ann
authors.initials: A
authors.lastname: Andersen
mesh_terms: D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D005818:Genetic Engineering / Q000379:methods*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D007763:Lac Operon / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D013050:Spectrometry, Fluorescence
chemical_list: D049452:Green Fluorescent Proteins