A single mutation in the core domain of the lac repressor reduces leakiness.

ABSTRACT:

Background

The lac operon provides cells with the ability to switch from glucose to lactose metabolism precisely when necessary. This metabolic switch is mediated by the lac repressor (LacI), which in the absence of lactose binds to the operator DNA sequence to inhibit transcription. Allosteric rearrangements triggered by binding of the lactose isomer allolactose to the core domain of the repressor impede DNA binding and lift repression. In Nature, the ability to detect and respond to environmental conditions comes at the cost of the encoded enzymes being constitutively expressed at low levels. The readily-switched regulation provided by LacI has resulted in its widespread use for protein overexpression, and its applications in molecular biology represent early examples of syntheti

SUBMITTER: Gatti-Lafranconi P 

PROVIDER: S-EPMC3722110 | biostudies-literature | 2013 Jul

REPOSITORIES: biostudies-literature