4RZS

Lac repressor engineered to bind sucralose, unliganded tetramer


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.71 Å
  • R-Value Free: 0.239 
  • R-Value Work: 0.199 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Engineering an allosteric transcription factor to respond to new ligands.

Taylor, N.D.Garruss, A.S.Moretti, R.Chan, S.Arbing, M.A.Cascio, D.Rogers, J.K.Isaacs, F.J.Kosuri, S.Baker, D.Fields, S.Church, G.M.Raman, S.

(2016) Nat.Methods 13: 177-183

  • DOI: 10.1038/nmeth.3696
  • Primary Citation of Related Structures:  

  • PubMed 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 resp ...

    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 β-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.


    Organizational Affiliation

    Wyss Institute for Biologically-Inspired Engineering, Harvard University, Boston, Massachusetts, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Lac repressor
A, B, C, D
381Escherichia coli (strain K12)Mutation(s): 4 
Gene Names: lacI
Find proteins for P03023 (Escherichia coli (strain K12))
Go to UniProtKB:  P03023
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GOL
Query on GOL

Download SDF File 
Download CCD File 
A, B, C, D
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.71 Å
  • R-Value Free: 0.239 
  • R-Value Work: 0.199 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 91.090α = 90.00
b = 111.600β = 90.00
c = 189.330γ = 90.00
Software Package:
Software NamePurpose
XSCALEdata scaling
PDB_EXTRACTdata extraction
PHASERphasing
XDSdata reduction
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2015-12-23
    Type: Initial release
  • Version 1.1: 2016-01-06
    Type: Database references
  • Version 1.2: 2016-03-02
    Type: Database references
  • Version 1.3: 2017-11-22
    Type: Refinement description