4RZT: Lac repressor engineered to bind sucralose, sucralose-bound tetramer

Citation:
Abstract
Genetic regulatory proteins inducible by small molecules are useful synthetic biology tools as sensors and switches. Bacterial allosteric transcription factors (aTFs) are a major class of regulatory proteins, but few aTFs have been redesigned to respond to new effectors beyond natural aTF-inducer pairs. Altering inducer specificity in these proteins is difficult because substitutions that affect inducer binding may also disrupt allostery. We engineered an aTF, the Escherichia coli lac repressor, LacI, to respond to one of four new inducer molecules: fucose, gentiobiose, lactitol and sucralose. Using computational protein design, single-residue saturation mutagenesis or random mutagenesis, along with multiplex assembly, we identified new variants comparable in specificity and induction to wild-type LacI with its inducer, isopropyl beta-D-1-thiogalactopyranoside (IPTG). The ability to create designer aTFs will enable applications including dynamic control of cell metabolism, cell biology and synthetic gene circuits.
PDB ID: 4RZTDownload
MMDB ID: 134963
PDB Deposition Date: 2014/12/24
Updated in MMDB: 2017/12
Experimental Method:
x-ray diffraction
Resolution: 3.1  Å
Source Organism:
Similar Structures:
Biological Unit for 4RZT: tetrameric; determined by author and by software (PISA)
Molecular Components in 4RZT
Label Count Molecule
Proteins (4 molecules)
4
LAC Repressor
Molecule annotation
Chemicals (4 molecules)
1
4
* Click molecule labels to explore molecular sequence information.

Citing MMDB
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